# Delta 40-601 SS rehab help



## MrUnix

A couple of weekends ago at a yard sale, I ran across a Delta 40-601 18" scroll saw that I couldn't resist taking home with me. It worked, but it couldn't keep a constant speed and varied from dead slow to super fast. The PO told me that it had a bad speed sensor and had already yanked it out (it was sitting on top of the machine). Other than that, it was in great shape, had it's original metal stand, a quick change kit (new - still in the box) along with about a hundred various blades (most still new in unopened packages). For $35 I figured the blades and quick change kit alone were worth it.

So, I got it home and started looking for some place to get a new sensor. Doing the research, I noticed that the majority of speed problems with these saws was not the sensor, but the 'speed control rotor' that the sensor works with to determine rotational speed. Seems they were made of some kind of bakelite material and had a habit of breaking apart. I got around to opening up the machine and sure enough, the rotor was gone, but the metal hub was still there. Grrrr.. Ok, yet another one of those parts that is no longer available. However, I did garner from my digging around the net that the sensor picked up a magnetic pulse from the rotor, so I got a wild idea to try and make one to replace it with.

The rotor is about 2" in diameter, so I got out my 2 1/4" hole saw and threw it in a drill press. I had some scrap hardwood (cherry I believe) and made the circle, then used a forstner bit to make a hole for the metal hub. I dug up a small rare earth magnet in my box-o-junk and embeded it on the edge, glued in the hub and gave it a try.










To my surprise, it worked! But I'm pretty sure it's running much faster than what the speed indicator tells me, and maxed out, the thing feels like it wants to explode (way, way too fast!). However, the slowest speed it runs at is just about as slow as I would ever want to go, and I can ramp it up for larger stuff if needed.. so all in all, I'm pretty happy with it.










(You can see the speed sensor installed just above the rotor)

Now.. my question for those of you in the know.. I am pretty sure that those original rotors had more than one magnet in them, but not sure how many or how big. I would love to have an original to examine, but if someone who has one of these saws could just tell me what theirs has, that would be fantastic. It's pretty easy to get to.. you just remove the four screws holding the gear box cover on the bottom and it's right there. By rotating the gears and using a piece of metal, it should be pretty easy to figure out how many embedded magnets are in the rotor.

Any help would be GREATLY appreciated!!

Cheers,
Brad


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## OldWrangler

Go to eReplacementParts.com and put in Delta Scroll Saw 40-601. They probably have the part and the4y also have a schemematic of the machine that might help. Great people and if they don't have a part, they will find one. Try'em.

Download Diagram 
Fig # Part # Img Part Name Availability Price Qty 
1 430031020002 
Yoke 
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2 901041500202 
Set Screw Obsolete - Not Available 
Discontinued 
$0.00 N/A 
3 430031060001 
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$35.35 
5 430034120001

Screw Assy 
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$9.06 
6 430031050001

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$1.28 
7 905010131507

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8 904152231506 
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9 961030102859

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10 430030890001

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11 901030103318S

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12 430030270002

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13 430030790002

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14 905010120303 
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15 905010102708

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16 908250131439

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17 430030270003

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19 422250680001 
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21 901030100760

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22 491957-00

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24 438010040080 
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27 928060231012 
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30 430030050002 
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31 430020790001 
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33 430030380001

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35 430030790004 
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37 430030310001 
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39 400061310022

Speed Sensor 
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40 901041509428S

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$1.51 
47 430030550001

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48 901030408015S

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49 904010101614S

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54 902020401303S

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55 430031080002

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## MrUnix

"*Go to eReplacementParts.com and put in Delta Scroll Saw 40-601. They probably have the part and the4y also have a schemematic of the machine that might help. Great people and if they don t have a part, they will find one. Try em.*"

Been there, done that 

DeltaMachineryParts, eReplacementPartrs, toolpartsdirect, mikestools, acetool, etc.. all have them either listed as obsolete/not available or "special order".. I contacted Delta and they told me they are no longer available. I also contacted any supplier that had them listed as available but 'special order', and they all told me that they couldn't get it either. E-bay has been a bust as well. Hence my fabrication above!

Cheers,
Brad


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## Redoak49

I think that there are a couple of things that you might try. You could put a meter on the output of the sensor and see what happens when the magnet goes by. It maybe a hall effect transistor. You could then tell if the current magnet is working. If it is, I would just try adding a second magnet and see if the speed is in the proper range.

I did some searching online also and you are correct that it does not seem to be available but there are some good pictures of the sensor and the magnet with the wheel.


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## kyscroller

Brad I just pulled the bottom off my 40-601 and looked at it. There are no magnets showing but I can tell you it is magnetic all the way around it. They are not very strong though. I held a scroll saw blade lightly while rotating it looking for a non magNetic point on the wheel. Might want to try picking up some of those flexible strip magnet from like Michaels and glue it to the edge and see if that may work better. Hope this helps.


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## MrUnix

"*Brad I just pulled the bottom off my 40-601 and looked at it. There are no magnets showing but I can tell you it is magnetic all the way around it. [...] Hope this helps*."

Thanks a bunch for looking at your machine, however, now I'm totally confused !!!

The sensor obviously picks up some kind of magnetic signal from the rotor, as otherwise my 'fix' wouldn't be working at all.. a continuous magnetic field doesn't seem like it would offer any input at all to the sensor! Maybe they are just spaced so close to each other that it appears to be continuous.. I dunno. I think my next move is to try and find a way to measure the speed it currently runs at (at the slowest setting) and compare that to what it 'thinks' it's running at via the front indicator (40 SPM). If I can get a ratio (actual vs indicated) then I might be able to figure out how many more magnets it needs. I was hoping this would be a bit easier to figure out!

Cheers,
Brad


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## nicksmurf111

If it's a hall effect sensor, I think all you need is a chunk of metal. You need to know how many lobes the original had on it. If the original had 4 lobes, and you are trying to use 1, it will run 4 times as fast. Look up how a ignition coil pickup on an 1970's vehicle works, or even the crank and camshaft sensors on modern vehicles. It's just a chunk of metal with teeth which induces a very small voltage into the winding.


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## nicksmurf111

I was looking at the picture and there is no indication how many pieces of metal are in the thing.

http://www.mikestools.com/430-03-100-0001-Delta-Speed-Control-Rotor.aspx

This picture on Ebay shows 4 casting marks in the palstic. But I think that's probably from the mold.

http://www.ebay.com/itm/Speed-Sensor-Rotor-430-03-100-0001-for-Delta-40-601-18-034-Scroll-Saw-/261447031797?nma=true&si=rtX0%252FPwCcl1Ej7FbFyazAGN57TI%253D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557


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## Rwood

sounds like I might help. I had two 601's sold 1 to a guy from work , 3 weeks later his rotor shattered 
Took mine off,thinking I could turn one out on lathe .
To count magnets I used one of those hard to reach expandable magnet tools , stuck it on vise held the rotor close ,
Counted 28 pauses . Not very strong mags but easy to count
Thinking I will try hole punching some those flat icebox mags ,not sure how to apply to new rotor


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## MrUnix

> Counted 28 pauses . Not very strong mags but easy to count
> Thinking I will try hole punching some those flat icebox mags ,not sure how to apply to new rotor


Wow..

I know mine is running fast with just 1 magnet.. but I can't imagine that it's running 28x fiaster! Even so, it is functional as is and I've been giving it a pretty good workout lately. First scroll saw I've ever owned and I am having a lot of fun with the thing.

Thanks a zillion for taking the time to check it out. We all finally know the answer to 'how many magnets'  I also like your idea of the fridge magnets and may give that a try to see how it goes. I'm thinking that they could be attached (glued) to the outside edge of the rotor then the whole thing covered with a couple layers of polyurethane or even painted over to help keep them in place. Maybe get fancy and fill in the gaps between magnets with some epoxy or something. Sure would be easier if I had a lathe!

Cheers,
Brad


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## MrUnix

Just an update on this..

A few months ago I picked up a nice little Delta lathe (~1948 model 46-110) that I finished restoring a couple weeks ago. Came out really nice and works great, so I decided to try fabricating a better speed rotor for the scroll saw with it.. I wanted to try the refrigerator magnet idea to see if they were strong enough for the sensor to detect. I grabbed the strongest magnet I had on the fridge, which still is pretty weak as far as magnets are concerned. Then I punched them out using a standard hole punch. The punch produces a circle just a gnats hair smaller than 1/4 inch, and a 1/4 inch forstner bit was used to drill the slightly recessed holes for them to sit in. I glued them in and then coated the whole outside edge with a couple coats of polyurethane to keep everything in place.










Unfortunately, it didn't work. It acted just like it did when I first got it (without a speed rotor), with the speed all over the place varying from fast to slow and back. It seems those magnets just don't have enough strength apparently. Next step is to try and find some stronger magnets. Updates to follow when I do.

Cheers,
Brad


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## HappyBob

You might try adjusting air gap to .010. This info I found on vintagemachinery.org website under the publications reprint section scroll saws dated insert 03-10-2005. The rotor p/n 125 would have had metal spaced around it "teeth" that the sensor would "count" and send pulses generated by the "hall effect" pick-up sensor p/n/39 to the controller. Also found that this rotor was used on lathes 46-400 type1 & 2. The metal teeth are just that- metal and not magnets.
Hope that this helps.


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## MrUnix

Thanks Bob.. I have that service buliten and did set the sensor gap to 0.010" or better. Also, there appears to be some disagreement about what is actually in the rotor. You can't really tell by looking at an original one as they just look like a plain plastic disc with a metal hub. Some (like you) say it's just metal, others say it's magnets. My original attempt at making a replacement rotor used a single magnet, and it did actually work to regulate the speed.

If it is a Hall effect sensor, like I and most others believe it is, then the rotor should have magnets in it. Hall effect sensors vary the output voltage in response to a magnetic field, which kind of supports the magnet theory. However, I made a custom faceplate for the lathe to make it easier to make the rotors, so I can fab up a small batch of them and test various configurations.. magnets, different types of metal, number of them around the rotor, etc..

Cheers,
Brad


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## nicksmurf111

All the hall effect sensors I have seen use a ferrous metal rotor. Go look at the anti lock brakes on your car, or the cam or crankshaft sensor, or a distributor made between the 70's and 90's.


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## MrUnix

Not to get off topic, but there are two major system types of non-contact speed detection of a rotating shaft (well, three if you include optical); inductive and active. For inductive, the magnetic field is inside the sensor and it measures the field change as a frerromagnetic rotors teeth are passed by it. Active sensors use a Hall effect transistor to vary it's output voltage as an external magnetic field passes by it. What type is used on these scroll saws is currently unknown, but I do know that it worked when I used a magnet, which leads me to believe that it's a hall effect sensor, not an inductinve one.. but I will test both to be sure.

Cheers,
Brad


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## nicksmurf111

I see. My father sells inductive type ones for manufacturing (robot) uses. Quite amazing, but simple at the same time.


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## MrUnix

Update.. *SUCCESS*!

I ordered a batch of 100 1/4" rare earth magnets from Amazon to try out in the rotor (really cheap.. just under $7 and free shipping). Apparently though, these things literally came over on a slow boat from China.. I ordered them online on October 20th and just got them yesterday (November 17th).. and the labels on the envelope (in both english and chinese) were marked "China Post"! Heck, I don't care.. they were cheap and I wasn't in any real hurry.

So I made up a rotor to test, installed the magnets and threw it in.. and it worked great. It's a completely different machine now and runs like new. So for anyone with one of these saws with a busted rotor, there is hope! Even though the stock rotors are no longer available, one can be made fairly easily for a couple of bucks. Thanks to everyone who helped me solve this problem! It would have been a big green paper weight without the assistance.

Cheers,
Brad

PS: As an added bonus, using the much stronger rare earth magnets makes the air gap setting between the sensor and rotor completely non-critical. I forgot to adjust the sensor when I tested the new rotor, and there was about a 1/8" or larger gap.. still worked great and moving the sensor closer had absolutely no effect on how it ran. Kind of makes sense, as rare earth magnets were very, very expensive back when these machines were made, so they most likely used much weaker ceramic magnets which required closer placement.


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## Bevo77

Mr. Unix, I purchased this scroll saw in 1988 and enjoyed it until a few years ago when the speed started varying uncontrollably. I left it alone until last week, when I disassembled it and discovered the Speed Sensor Rotor in pieces. I then started the web search for replacement parts and discovered your post. I am going to try your repair as the rest of the saw is in excellent condition. I am going to order the "slow boat from China" magnets but I am unsure what glue to use. What did you use to glue the magnets and how did you attach the the replacement rotor to the existing shaft? I would appreciate any info. and suggestions.


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## MrUnix

You can probably use any glue you like.. I just used regular wood glue (titebond). I drilled 1/4" holes about 1/16" deep with a forstner bit just like shown in my post up towards the top of this thread. Once they were glued in, I made sure they would not come out by coating the outer edge with a couple coats of polyurethane which sort of sealed everything in place. Initially when testing, I just wrapped the outer edge with some electrical tape and that worked just fine as well. One tip that might be useful: I found that the interaction between magnets made them want to flip and pop out occasionally when trying to put another one next to it.. so I cut down some stick pins from my wifes sewing box and stuck them in each hole with the head slightly sunk into the wood.. this gave the magnets something to stick to while I was installing them.

As for securing to the shaft, you can re-use the metal hub from the original rotor like I did with my first prototype (with one magnet). What I eventually wound up doing was to make a wooden faceplate for my lathe with a 3/8" bolt centered on it. I drilled a 3/8" hole in a wood blank, mounted it on the faceplate and then turned it on that.. which ensured that the rotor was perfectly centered around the shaft. I started out with about a 1" thick piece of stock and made an extended hub that I could then drill and tap for a set screw (#8-32) that I made from a spare screw (just cut the head off and use dremel to make a screwdriver slot):










After drilling and taping, I sanded the hub down so the whole thing was just a bit shy of 3/4" thick, which is about as wide as you can go without running into clearance problems. It fits pretty snug on the shaft anyway, and with the set screw lightly tightened against the flat spot on the shaft, it ain't going anywhere.

Cheers,
Brad


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## Bevo77

Brad,

Thanks for the quick reply. I will give this a try and let you know how it works out.

Jeff


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## jebx

Brad,

First off THANK YOU!

Just curious how many magnets you ened up putting on the final rotor?

You should whip up a few more rotors with the extra magnets and sell them.


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## MrUnix

Thanks Jeb (and Jeff!),

The rotor really needs 28 magnets, but because I bought 1/4" ones, there is no way to fit that many on a 2" diameter rotor (you can maybe get 24 or thereabouts if you place them really, really close to each other). Since my lathe has 60 indexing holes, I just went with 20 to make things easier. It still works just fine, although it does run slightly faster than what the front indicator says it is.. which I haven't found to be a problem at all so far. The slowest speed it can be set to is 40 spm which is way, way to slow for anything I can think of doing, and with the 20 magnet rotor, it is still way too slow for any useful work (probably closer 60 spm with the replacement rotor). And the upper end of the speed range is well beyond anything I would want to use, so even with the replacement rotor, there is a nice wide speed range available.

I've thought about ordering some 1/8" magnets and trying to make some with 28, but since the one I have works so well, I'm not all that motivated and would rather just cut wood  As for making extras and selling them, I'm not sure there is much of a demand.. but if enough people express an interest, it wouldn't be too much trouble to crank out a few extras.

Cheers,
Brad


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## Kyzach

This thread gave me a little inspiration to tackle the broken rotor on my scroll saw. I used the original hub from the rotor and 1/2" plywood. I used 24 magnets because that's what came in the package I bought. I'm not really concerned with the accuracy of the readout, so long as the speed is stable. I put the magnets on edge to allow more magnets. I coated the assembly with epoxy to secure it all together.


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## MrUnix

I like the idea of placing them on edge like that.. did it work? Just curious because the magnetic field radiates off the faces of the magnets, not the edges (which is why I placed mine flat). Orienting them like that would solve my space problem, and I could make up a rotor with the correct number of magnets (if and when I get the motivation to mess with it more)!

Cheers,
Brad


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## Kyzach

So far it seems to be working good. There's a bit of vibration I still need to address. I'm not sure if my modification is causing it or if it's something else. I bought the saw broken for $45. Even with the vibration, I think it was worth it. If I discover the cause, I'll post it here.


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## Kyzach

I'm pretty sure my counterbalances are not aligned correctly. I didn't consider marking them before I pulled the assembly apart to replace the rotor. Is there an indexing mark or some other approach to getting these lined up correctly?


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## MrUnix

> I m pretty sure my counterbalances are not aligned correctly. I didn t consider marking them before I pulled the assembly apart to replace the rotor. Is there an indexing mark or some other approach to getting these lined up correctly?


No indexing marks that I'm aware of, or at least I didn't see any.. I did mark them before disassembly so I would be sure to put them back in the correct position. Here is the best picture I could find of them which might give you a good idea of their orientation.. you might have to mess with them a bit, shifting by a tooth at a time until you get them in the right position, but it should get you close as a starting point:










Cheers,
Brad


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## Kyzach

Thank you for the quick response and the picture. After looking at it, it makes sense the counterbalances would be opposite of each other. I'll start from there and move it a tooth at a time like you suggested.


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## CastIronMan

I recently bought a Delta 40-601 Scroll Saw from a retired 85-year old woodworker. He was asking $125 for it, which included the stand and original manual/parts list. This guy used to be a Delta Tool Dealer. He had a Delta Radial Drill Press and Delta 14" Bandsaw too, but they were not for sale. At least not yet..

The Saw generally runs at a constant speed (stays at the selected speed based on the speed control knob setting). It will drift a little, and surge a little bit at speeds under 100 SPM. The Service manual says that is normal.

What doesn't sound normal, at least to me, is the noise in the gearbox region, which sounds like gear noise.. At this point, I am not sure if the noise is coming from the gears, or bearings on the gear shafts, the counter weights, or the drive arm that is attached to the motor counter weight..

I have posted videos of the Saw in action, one of which is a close up of the gearbox region. The sound is prominently coming from the gear area. I have put my ear up to the motor, and that sounds fine. The bearings at the middle of the C-Arm (the C-Arm pivot shaft) seem to be quiet as well.

I could use the Saw the way it is, but I would prefer to eliminate the noise if possible. This is my first Scroll Saw, so I am not very familiar with them or this particular model. What attracted me to it was its ability to run at a very slow SPM rate, and its ability to cut metal, and cut plastic without melting the plastic.

Do to the noise issue, I got him to come down on the price to $100. So that is what I payed for it.. He said he had only ever cut wood on it. He never tried to cut metal or plastic. It has a Quickset II Blade Chuck for the upper end blade mounting and dismounting.

It is generally a clean looking Saw. There is some wood dust and grit on the gears, and counter weights, but the overall condition is good compared to some others I have seen. This Saw was manufactured in December 1992.

What do you guys think might be causing the noise, you think it is the gears?

Videos below were shot at night, with a 60 watt desk lamp, using an iPhone. Don't know how to embed videos on this particular forum. I tried but it didn't seem to work so, I just posted links..


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## MrUnix

Got no idea.. does sound like something rubbing/hitting though. Only suggestion would be to yank it apart, clean it out a bit and try to narrow down things. Also, it seems to kind of go away when you turn up the speed a bit.. I cannot imagine any time that you would ever run it as slow as you had it, and really have no idea why Delta would have designed it to go that slow anyway.

Might try disconnecting the link arm and running it to isolate the motor from the equation. Check those bearings in the link arm while you have it off.. I had to replace the lower one on mine as it was a bit crunchy when I bought the saw.

Cheers,
Brad


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## CastIronMan

I initially thought there might have been rubbing/contact, between the two counter weights or the connecting rod and the motor shaft counter weight. What you are calling the "link arm", Delta refers to as the "Connecting Rod". I only see 4 bearing locations in the gearbox area. One bearing on the gear side of the Speed Sensor Rotor shaft. One bearing (a closed end Needle Bearing, on late saws like mine) on the Speed Sensor end of the Speed Sensor Rotor shaft. One bearing in the lower end of the Connecting Rod. And maybe a bushing (don't know if that is a bearing or bushing) in the upper end of the Connecting Rod.

I'm thinking the noise is either coming from the two gears themselves, due to wear and age. Or from one or more of those bearings.. I'll have to attempt to disassemble the parts inside there.. They all do need to be cleaned..

How did you replace the bearing in the lower Connecting Rod? Did you need to use a bearing puller and bearing press to do the job?

As you can see in the photos below, the gears in my saw are not quite lined up end to end, width wise. There is a bit of an overlap between them. I'll try to fix that and get them perfectly lined up to each other. I think it is going to be a bitch to get all those parts out of there, and put them back in..

These gears are no longer made or stocked by Delta. Quality Aftermarket reproductions of them would be nice.. Better yet, Delta should have put metal gears in these saws, instead of plastic. Or for strength, a double roller chain and metal gears set-up like the timing chain assembly in a Mopar 340 V8 Engine. A toothed belt drive, with toothed pulleys would have been quieter and probably would have lasted longer than the gears. Either of those solutions would be superior to the two plastic gears (they might be made of bakelite)..





A photo of the 22-year old, arthritic Delta 40-601:



I hope this ends up being better than a $100 Harbor Freight, "Made in China" Scroll Saw..


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## MrUnix

Call the thing whatever you want 

You can get the bearings out fairly easily with a wood dowel or pin punch and a soft blow hammer.. I used a press to get it back in just because it was too hard to line up a C-clamp with that small of a bearing and I had access to my father in laws press (only time I've ever used a press for a bearing, and I've done hundreds of bearing replacements over the years!). It does look like there might be some contact between your counterweights, which is an easy fix.. just loosen the set screws (there are two of them if I remember correctly), slide it over a bit and re-tighten. You may need to do the upper one instead of the lower one if the arm doesn't line up right.. you should be able to determine that once you get in there and see how they line up. The gears are not really a problem and metal would probably have caused even more noise. The machine is really very easy to take apart. I wrote up the disassembly/assembly procedure a while back and can send it to you if you like.

Cheers,
Brad

PS: There is a small washer that is used as a spacer between the bearing and counterweight where it attaches to the connecting rod using the socket head screw. Mine was worn down considerably and needed replacement.. that might be something you would want to check as well.


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## CastIronMan

Brad,

I don't have a bearing press.. I will check that spacer washer on the connecting rod.

Yes, if you could send your disassembly/assembly procedure, I would appreciate it!

I can't send you a PM, yet (not enough posts made), but perhaps you can send one to me and I can respond to it.

Thanks,

Steve


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## MrUnix

You really don't need a press.. bench vice, C-clamp, vice grips, laying it flat and tapping it in with a soft blow hammer.. lots of different ways. Like I said, I've done hundreds of bearing replacements and never needed a press; just happened to have access to one at the time. Will send the instructions via PM.

Cheers,
Brad


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## CastIronMan

I didn't quite find it easy to take apart. The table support 5/8 inch bolt would not budge.. I tried several closed end and open end 5/8 wrenches, none of which were a real snug fit around the bolt head. Then I found one closed 5/8 wrench in my tool box that fit the bolt like a glove. I put that on and hit the end of the wrench with a hammer a few times. That resulted in the wrench itself bending! The bolt still would not move.. I was trying to turn counter clockwise (Lefty Loosey, Righty Tighty) So, I gave up trying to loosen that bolt. I didn't want the impact of the hammer sending shock waves to the electronic speed control board or to strip the head of the bolt.

Similar problem trying to loosen the hex screw, that secures the connecting rod to the motor shaft counter weight. Couldn't get that to budge either.. I was trying to hold the counter weight with my hand while turning the hex screw with a T-Handle hex wrench. My hands aren't strong enough apparently to hold the counter weight in place while torquing the screw..

I verified that there was no physical contact occurring between the two counter weights. I grabbed the connecting rod, at the bottom, with my hand, and slowly turned the motor shaft. I did this after removing the bottom plate of the Air Bellows Pump. It seemed as though the bearings are all good and quiet.

The plastic gears on the other hand, have a little slop in them. I could grab one of the counter weights and wiggle it back and forth a little bit, hearing and feeling some slop between the two gears, as they changed direction from the wiggling.

I was able to loosen the set screws on the counter weight/gear that is mounted on the speed control rotor shaft. I then slid that a little over towards the speed control rotor. Making sure the two gears were perfectly aligned, edge to edge, without any overlap. Then tightened the set screws back down. I checked the tightness on the other set screws for the motor counter weight and the speed control rotor. They were fine.

After doing this gear alignment, the noise has definitely been reduced at speeds under 600 SPM. Overall, I still get noise, but not quite as bad as before. A little improvement.. I ran it up to 1000 SPM today, during my tests. Vibration of the saw is low at speeds under 800 SPM. But when I get to 1000 SPM there is a definite increase in overall vibration. I had turned the speed up to 1750-1800 SPM at the old man's home, before I bought it. Thinking if it was going to break down, it would do it then, before I paid money for it.. It survived that test..

I really do think the noise is coming from the gears, due to the slop and some wear on them. I don't think I'm going to get any more noise reduction, without replacing the gears, which are not available.

I put Labelle 106 white grease on my mixed plastic and metal gears, in my Tamiya 1/16 RC Tiger Tank's gearboxes. Labelle 106 is formulated for use on Plastic Gears, and contains PTFE (slickest substance known to man, they say). I'm wondering if I put some Labelle 106 on the Scroll Saw gears, if it might help to quiet them down. The only issue with that, is saw dust will find its way down to the gears, as it already has, and the saw dust will stick to the white grease. Not sure if the mix of the grease and sawdust would harm the gears, or cause additional problems…

There is no mention in the Delta manual of applying any kind of grease on the gears. Apparently, Delta just ran them dry with no lubrication of any sort. Which accelerates the wearing of gears, when they have no lubrication. Perhaps this was because of the gears being exposed to saw dust (from wood, plastic and metal)?


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## MrUnix

As long as nothing is hitting/binding, start making saw dust! That 5/8" bolt should not be that tight.. it allows you to rotate the table, but it's not that common to do so, so I wouldn't worry too much about it. I would however check to make sure that the connecting rod is not hitting the counterweight.. it looked really close in your picture and that washer/spacer keeps if far enough away to clear it.. if it's worn, that could be the source of your noise. Mine was worn down to almost nothing. A hex key socket and socket wrench might be helpful to get it loose.. maybe spray it down with some penetrating oil for a while before trying again.

Cheers,
Brad

PS: Instead of trying to hold the gear/counterweight, position the hex key so you can use the connecting rod for leverage.. then just squeeze the two together (pulling the hex key towards the rod and visa-versa). Makes it much easier, and with the socket/socket wrench you will get more force.


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## CastIronMan

I was using a Hex T-Handle through the hole, in the side of the cast iron base, after removing the black plastic plug. Inserting the Hex T-Handle shaft through the hole, into the connecting rod hex screw.

I could stick another Hex T-Handle in one of the counter weight set screws to keep the shaft from turning, while torquing the hex screw.. I didn't try that.

The method you describe seems like it would require Iron Man finger strength. I don't have a hex socket..

Do you have any opinion or comment on applying grease to the gears?


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## MrUnix

I don't think grease is necessary, but I don't think it would hurt anything either.. those gears are enclosed and really shouldn't get any sawdust in there.

Don't know what to tell you about removing that socket head screw.. sometimes things just don't come apart easily and you need to figure out creative ways to get them loose. I've had rusty, dirty and neglected machines that came apart easily, and the stuff you think will be easy is a PITA. Just try not to break anyting.. that can ruin your day ;-O

Cheers,
Brad


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## CastIronMan

I was finally able to remove the connecting rod hex screw, by placing a socket underneath the connecting rod to hold the rod in place, while torquing it with the T-Handle wrench.

I found evidence of metal to metal contact, between the perimeter edge, of the round end of the rod that surrounds the bearing. The photo shows bright metal rubbed spots, about half way around the diameter of the round end of the rod.



Here you can see the counter weight. There appears to be a little groove worn into the surface of the weight, seen in the right side of the photo.



The Shim Washer is part #904-01-021-3590. Don't know if this is still available. Maybe I can find a suitable replacement at a hardware store..

My Shim Washer, currently measures as follows:

Thickness = 1/64 inch (0.5mm) (don't know how thick it originally was supposed to be)
Outside diameter = 12/32 inch
Inside Diameter = 10/32 inch

Don't have Vernier calipers, so I measured using a metal scale ruler, used for measuring guitar string height above fret boards.

Brad, was yours thinner than this? And what thickness washer did you replace it with?









Some photos of how I set the saw up to work on it


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## MrUnix

The washer in mine was worn paper thin.. I just grabbed the thickest washer I could find out of my box-o-junk that looked like it would fit.. thickness shouldn't matter.. it's just there to keep the parts from hitting like yours apparently was. Only thing you need to make sure of is that it's not too big in diameter so it doesn't hit the bearings outer race, and the inner hole is small enough to rest on the bearings inner race I bet you can find one that will work out in your garage  Take the old one out there with you so you can kind of match it up.

That was probably your problem. These machines are 100 times better than those sheet metal and plastic things you find today. Slap a washer in there and start making some sawdust.

Cheers,
Brad


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## CastIronMan

I didn't have any washer laying around that was even close to the same size.

I went to Ace Hardware, and found the one below, which was the closest size they had to the original. It is metric, 1mm thick, making it double the thickness of the original. Problem is the inside diameter is too small. The Hex screw will not pass through it.

Once I get a drill press and a press vice (neither of which I have yet), I could put the washer in the vice and drill it out to match the inside diameter of the original washer. This new one is slightly larger in outside diameter, but very close to the original.

They had a washer that matched on the inside diameter, but was more than just slightly bigger in outside diameter.. The inner race of the bearing is very narrow, about the same size as the original washer. The inner race doesn't protrude very much in height above the bearing.. Maybe I should have gone with the correct inside diameter and larger outside diameter. I didn't want it to rub on the bearing, I think it would clear the outer race though..

The store closed at 5PM, so will have to wait till tomorrow evening to get the larger washer.

If you just grabbed one out of your "junk box" that fit properly, you were lucky!

Wouldn't be making an sawdust this weekend anyway, as I broke the only blade that came with the saw.. I had accidentally left the pin rod inserted in the lower blade chuck when I tightened the tension on the upper blade chuck. Then when I pulled on the C-Arm to raise the whole blade up, SNAP, it broke.

The old man had a garage sale about two days before I went to look at the saw. He had the saw available and a bunch of blades for it to be sold together as a set. Some guy that came by, wasn't interested in the saw, but he wanted to buy just the blades. He sold him the blades only. So, I only got the one blade, that was mounted in the saw..


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## MrUnix

*If you just grabbed one out of your "junk box" that fit properly, you were lucky!*

You've never seen my stash 

I've saved just about every nut, bolt, washer, circlip, spring, cotter pin, screw… and just about every other part I can scrap off old machines for the past 40+ years that I think might be usable sometime in the future. I really hate going to the hardware store just for a 4 cent washer!

Cheers,
Brad


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## CastIronMan

> I really hate going to the hardware store just for a 4 cent washer!
> - MrUnix


That washer cost me 13 cents.. Plus, at least 13 cents in gas to drive over and get it.. haha You are older than me, I was only 7 years old, 40 years ago..


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## Ronmu

Brad,
Great job! Thanks for this thread. I just picked up a 40-601 today. I really liked how well this scroll saw is built. I do also have speed control issues. In one of your previous post you mentioned posting disassemble instructions, I looked but could not find. Could you please send me your notes? 
Thanks, Ron


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## MrUnix

PM Sent with the instructions.

Cheers,
Brad


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## MrUnix

Steve, a lot of times I can find out the sizes/dimensions of various parts by searching for the part number and looking at what shows up at the various aftermarket parts suppliers and other places.. you can sometimes get additional information that is lacking in the original documentation and parts lists, and most of them are just standard off the shelf hardware items.

Sooo… looking for that particular washer, I did a quick google for the part number (904-01-021-3590 shim washer). Sure enough, I found a listing at SearsPartsDirect that has the size, where it states: *This plain washer measures 17/64×1/2×1/32 inch.* Looks like a standard USS 3/16" washer would work (ID: 1/4", OD: 9/16" Thickness: 3/64"). The ID might be a little tight, but could easily be opened up a bit with some sandpaper or a needle file if needed.. probably won't be necessary though.. the bearing has an ID of 1/4" as well.

Cheers,
Brad


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## Ronmu

Brad,
Nice job with the instructions and this thread. Did you ever upgrade to 28 magnets?
You will be the "guy", whose work will save the 40-601 from becoming an anchor. 
In Appreciation,
Ron


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## MrUnix

Thanks Ron.. no, I'm still making sawdust using the 20 magnet rotor I made.. it works perfectly for me, so I'm not really all that motivated to make up a new one just so the front indicator shows the real speed 

Maybe one of these days I will.. but for now I'm just happily cutting wood with it.

Cheers,
Brad


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## CastIronMan

Brad, thanks for the washer info. I had made a mistake in my measurements of my original washer when I posted them earlier in the thread. The inside diameter of the washer is just slightly over 1/4". Outside is about 3/8". I think that hex screw would actually fit inside a 1/4" hole, even if it was exactly a 1/4" and not slightly oversized.

I bought a drill press off craigslist tonight for $40.. Thus far, I'm not sure if it was really a deal or not, I will find out once I get it cleaned up and put together. It is a Craftsman 9-inch bench top model #137.219090. 1/3 HP, 5-Speed, 1/2" Chuck. The bad part is the cast iron base is covered with surface rust, and so is the support tube. The support tube has less rust than the base.

The seller of this press bought it about 4 or 5 years ago, and never got around to taking it out of the box, assembling it, or using it. For a time he had stored the box outside and it got rained on. The base plate and the tube were near the top, right underneath the box lid. Water leaked into the box and got them wet, hence the rust. The rest of the drill is 95% rust free.

The V-Belt was wrapped around the pulleys and under some tension for the entire time it sat in the box. So the belt his conformed to the shape it was in, when stretched around the pulleys. It is a K-27 V-Belt. I'm not sure if I'll be able to use it, or if I'll have to replace it. I have worked it some with my hands to try to get it into more of a round shape.

With the drill head laying on its side, the drive motor shaft and pulley doesn't seem to be quite parallel with the spindle pulley and shaft. It tends to angle towards the spindle pulley instead of being straight up and down. It is yet to be seen, if once mounted on the support tube, instead of laying on its side and everything situated ,whether the pulleys will line up parallel to each other.

It did come with the a 3-inch Drill Press vice, which would probably cost about $15 to buy new.

I got tired of looking for an old Delta Drill Press. After a couple months of looking, a 1948 Rockwell model appeared for $100 and I called six hours after the ad was posted, but it was already sold. The China made presses sit for weeks, with no takers, unless they're priced low.. I bought this 5-year-old Craftsman as a stop gap, while I continue to look for a better press. The seller had failed to mention the rust before I drove over to his place to look at the press.. I came very close to leaving without buying it.. I gave in because I am tired of waiting for the right drill press to come along, and didn't really want to spend $70+ on a China made bench top model. And this $40 dollar special actually has a cast iron drill head.

I need to research how to remove rust from cast iron and steel tubing.. My 40-601 has very little rust on it in comparison. I've never really owned my own power tools before, so these machines are kind of new to me.


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## MrUnix

Surface rust is a non-problem. I love the stuff.. makes the price lower 

The belt and pulley alignment is not that critical.. just put it together and use it. I have a little C-man drill press that sounds similar to yours (#219120) and it's just fine for my needs and trouble free.

Cheers,
Brad


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## Ronmu

I had a small noise and vibration problem with my 40-601, I isolated the problem to the bearings in the connector shaft. After replacing the 2 bearings the scroll saw noise disappeared and ran very smoothly. Since I needed to find and replace the bearings, I decided to buy a couple of extra sets to make it available to others at my cost $15 + shipping. Hopefully this will save someone time finding these. I looked for the highest quality, 1 is Japanese the other is American. I will post them to Ebay, once the 2 sets are sold I do not plan to purchase or post any others.
Happy scrolling and a big thanks to Brad for his helpful post.

Ron


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## Ronmu

I had a small noise and vibration problem with my 40-601, I isolated the problem to the bearings in the connector shaft. After replacing the 2 bearings the scroll saw noise disappeared and ran very smoothly. Since I needed to find and replace the bearings, I decided to buy a couple of extra sets to make it available to others at my cost $15 + shipping. Hopefully this will save someone time finding these. I looked for the highest quality, 1 is Japanese the other is American. I will post them to Ebay, once the 2 sets are sold I do not plan to purchase or post any others.
Happy scrolling and a big thanks to Brad for his helpful post.

Ron


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## Kyzach

Just a quick update: I managed to pick up a second 40-601 to compare the gear orientation (because I didn't pay attention to it when I took my saw apart). With everything now aligned, my modified saw is actually smoother that the factory version. To be fair, the saw with the wooden rotor is an older "Made in the USA" model and the other is a newer overseas model. I'm not sure what the mechanical difference is; maybe it's just due to wear. Either way, the plywood rotor is working like a champ and it only took about 15 minutes to make.


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## Hobo5425

MrUnix,
I have the same problem with my Delta 40-601, I was using it today and the speed just got real, real fast. I took the bottom off and sure enough the speed control rotor had broke. Looked everywhere on the computer and all I could find is no longer available. What I would like to know is if I could pay you to make me one, I mean with the magnets and all ? I know I could probably do it myself but you've already made one. Please post your reply.
Thank you sir,


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## MrUnix

Would be happy to… but at the moment, I'm not in a position to make one and might not be for a while. I do have a blank (no magnets installed yet) that I could send you for free though. I could drill and install the set screw but you would need to glue on the magnets yourself.

Cheers,
Brad


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## Hobo5425

MrUnix, 
That would be fantastic , I just recently joined the LumberJocks, so I don't know how this works, do I put my address on this post? or what? I will be more than happy to pay you. Thank you so, so much.


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## MrUnix

> I just recently joined the LumberJocks, so I don t know how this works, do I put my address on this post? or what?


Not unless you want the whole world to know your address 

I'll PM you and we can work something out.

Cheers,
Brad


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## Hammerthumb

Although I do not own a scroll saw, I have found this post most interesting. Great work Brad!


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## Slicvickie

Hi all, 
New member here. I stumbled across this forum while trying to find the cause of my 40-601 speed up - slow down issue. I had planned to take the entire front speed panel out and swap in a variable controller meant for a router. If that didn't work, I'd be looking for a new scroll saw. This particular machine was brand new new in 1988, a wedding gift, (seriously!) from my (then new) husband. The scroll saw has outlasted the marriage by a decade and a half and probably has cut a hundred miles of wood. Seems a shame to scrap it after all that!

However, after reading this and a quick peek inside the gear box that showed multiple pieces of rotor, I think that must be the culprit.

Brad, I would appreciate a copy of your disassembly/reassembly notes as well. As a new member, it seems that I cannot send a PM yet.


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## MrUnix

PM Sent 

Cheers,
Brad


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## Renron

First Post, it only took me 4+ years to think about it!  
This is one of the BEST threads I've ever read. The information shared and creativity by the members here is a tribute to you all!
I'm going to look at a 40-601 this afternoon with a "speed problem"..........wonder what it could be??? LOL
He wants $60 for it including the stand, maybe I can get him down to $50. This will be my first scroll saw and I like repairing tools to make them functional again. (my 1956 Unisaw was a rust bucket when I got it) I'll post pictures if I buy it, and of it's repair.

Could someone please share the part # of the "quick change" blade holder upgrade. Sorry if the vernacular is incorrect. 
Can this accept the non-pin blades? Again, just learning the scroll saw language, sorry I don't know the proper terms yet.
Great thread!
Ron


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## MrUnix

I don't know the part number or even if there is a quick change kit for this saw… When I purchased mine originally, the seller gave me what they said was one for it…

It turned out to be for a Dremel scroll saw instead 
(OWWM Rule #1!!!)

The existing chuck isn't very difficult to use though, and once you get used to it, it becomes kind of second nature and you don't even think about it.

As for blades, it uses standard 5" pin-less ones. You can use pinned blades if you have them, but the pins need to be removed first.

Here is a link to the manual for the saw that gives the specifics for blades and such:
Delta 18-inch Scroll Saw No. 40-601 Instruction Manual

Cheers,
Brad


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## Renron

Thanks Brad,
I was most interested in which type of blade could be used. 
Flying Dutchman blades have a good price and reputation. 
I'll start with those and make lots of mistakes while learning what not to do.
Ron


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## cellarjim

This entire thread was a life saver. Thank you Mr. Unix and everyone else who contributed!


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## MrGrady0681

Hey guys, wood shop teacher here. This past fall I took over teaching in a shop with one of these scroll saws. After reading this, you guys seem pretty knowledgeable about it. It had been working fine, and just today it REALLY started to squeal. When I went back and investigated, it also appeared that the speed was becoming really inconsistent. I am fearing that it is the motor. What do you guys think? Is it worth repairing or should I be looking into getting another saw?

Jon


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## oldnuke

I'm new here and I know this is an old thread but it seems to have a life of its own for good reason.

I am currently looking at buying a used 40-601 and found this thread to be most informative. With a mechanical engineering background, I wondered if anyone had tried using a flexible magnetic strip in lieu of the individual magnets. It seems that you should be able to turn a wooden hub similar to that described above and create a slight recess on its edge to accommodate the width of the magnetic strip. Epoxy the strip into the recess and then simply cut 28 notches around the perimeter to create the necessary pulse signal.

I don't know if the saw I'm looking at will require such a fix at this time but based on the interest here, it does appear there's a good chance it will at some point in the future. I thought I'd throw this out there if anyone wants to give it a try.

Terry


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## Slicvickie

I finally got around to doing something with my saw!
I used a hole saw to make a new rotor and glued in the original hub.
I had all the pieces of the original rotor but only counted 24 magnet section, instead of the 28 that someone else had. So I went with 24 magnets. I Drilled holes and glued in rare earth magnets, then re-installed it. 
Plugged it in to give it a try and it worked for about 10 seconds. Then suddenly…Nothing!
I can hear the motor hum slightly but it will not spin. I can give the gears a push and it will move, so I don't think anything is binding, and I am sure the counterweights are correctly aligned.
My magnets are not in perfect alignment around the hub, but are within 1/16".
Any ideas what happened here?
Did I burn out the control board? The motor itself?

Edit…Just had another thought
I just stuck the magnets in one after the other off a stack of them so I probably have the polarity of them alternating…North/south/north/south all around the circumference.


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## Den01

Brad,

Just bought a Delta scroll saw with busted rotor. This site has been great for how to fix it. Since it is my first scroll saw, I would really appreachiate it if you could share you disassembly / assembly instrunctions. I have begun making my own magnetic rotor, and would to get it replaced properly. Thank you.


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## Den01

Does anyone have ideas for repairing the bellows in an older Delta 40-601 scroll saw. I love making the old stuff work, so I purchased this saw with a busted rotor disc. This site has been great for getting that repaired, but while fixing that, I noticed my bellows has a couple cracks. I will try to glue it shut, but don't have much confidence that will be a long term fix. If anyone has other tricks to try, I'd love to hear them. Bellow isn't critical to me…just nice to have. Thanks.


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## Renron

Den01,
I think I would try to find the thinnest bicycle inner tube I could, and patch past the tear(s) rather than try to glue them back together. Overlap the tear using a pliable glue and give it plenty of time to dry.

Couple of questions on the saw. 
If I run mine past 300 SPM it shakes violently and breaks the blade. I could have misaligned the teeth on the counter balance when I re assembled. Maybe I'm off a tooth or 2, Opinions?

When I move the tension lever rearward, it changes the angle of the blade holder, which puts a forward bow on the blade at the top causing the blade to align out of plumb. What am I doing wrong.

Thanks for the help.
Renron


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## MrUnix

> Does anyone have ideas for repairing the bellows in an older Delta 40-601 scroll saw.


I fixed mine using rubber glue… the stuff used to repair waterbed bladders. Tears are glued together and then covered about a half inch on each side with a thin layer of glue as well. Abrade with some sandpaper to give the glue something to bite into, and clean with alcohol to remove any contaminants before gluing. If that ever gives out and I can't fix it, a small fish tank air pump will do the job.



> When I move the tension lever rearward, it changes the angle of the blade holder, which puts a forward bow on the blade at the top causing the blade to align out of plumb. What am I doing wrong.


Are you using the locking pin when changing blades to make sure it is installed with the proper orientation? The tension lever simply pulls the clamp upward, and there should not be any forward/backward deflection (and I can't even imagine how it would cause it to do so).

Cheers,
Brad

PS: Den01 - Sent you the instructions via PM… let me know if you didn't get them.


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## Renron

Brad, thanks for the reply,
I just checked and I do not have grommet #9 under the arm. How thick is this grommet? Could be why my angle changes….. hmmmm.
TIA for the help.
Renron


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## MrUnix

> I just checked and I do not have grommet #9 under the arm. How thick is this grommet? Could be why my angle changes….. hmmmm.
> - Renron


I honestly didn't even know that grommet was there - I never took apart the clamp assembly. I guess it could have something to do with it, but I can't see what… it doesn't look to do much other than act as a little bumper to limit upward travel (instead of just hitting metal) and doesn't seem to be associated with tensioning at all; but I'm not 100% sure and don't really feel like tearing the thing apart just to find out 

As for size… after a little digging, it appears to be the exact same grommet as used on the stand (as tool holders in the corners, #152 on the diagram, P/N 961-03-010-2859). You can probably match one up at the hardware store for a few cents (or buy one online for a few bucks 

Cheers,
Brad


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## Renron

Brad, A big Thank You for all your help. After wrestling with this machine for over a year, I can now claim victory!
I purchased it from a man on Craigslist who said the speed dial just suddenly stopped working one day. He also claimed the fix was a light dimmer. Right…............ I purchased it for $50 and cleaned it up when I got home. It would run at either ~ 100 SPM or ~300 SPM then shake like it wanted to explode. I fashioned a new Speed Sensor Rotor using the hub from the broken bits of the old rotor. The gears were marked on the back sides for weight balancing. I used what I had and made a rotor with 21 magnets. (First Mistake) Installed Rotor and with same ~100 SPM or ~300SPM, shook like a wet dog. I used the gear aligning markings from the previous owner (Second Mistake)
Bad Idea, shook like a wet dog. Almost a full year passed and I decided to either fix it or send it to the dumps. Moving this thing around in my small garage workshop is not fun. I decided to start from Zero and use the information in this thread as a starting point and not rely on what the previous owner had said and done. I removed the Secondary gear set from the spindle and found it's natural balance point hanging straight down to locate which tooth or notch was basically the Top Dead Center. It's a tooth, located at the center point of an Allen bolt (1 of 3). Now I could locate the corresponding notch easily on the motor gear, it's centered on the Allen bolt directly across from the majority of the cast Iron weight. These new balance points were about 5 teeth off from where the previous owner had marked the gears. Ding! One down one to go. I then rebuilt a new Speed Sensor Rotor with 24 magnets. A 2 1/4" hole saw will work but is VERY tight clearance on the sensor. The Circumference is 7" & 9/32" , which works out to a magnet every 9.3/32" , that's 9 point 3, thirty seconds of an inch. I wrapped masking tape around the circumference, overlapped it and cut it with a razor blade, removed the excess from the overlap and laid the tape on the workbench. Now I was able to mark each 9/32 plus a tiny bit on the tape. When finished I put the tape back on the wooden rotor and cut slots on my marks. Worked perfectly. Epoxied the entire thing overnight and installed it with my new marks on the timing gears. During this process I also tore a hole in the boot for the air production. I used some Shoe GOO to make repairs because it has worked well other times I have used it for repairs. I did try to add an innertube patch as I suggested, but that failed upon first use, it was too stiff. This is how we learn. 
As of today, it runs smooth all the way up to 2000 SPM. The readout seems to read correctly too. Another old tool saved from the scrap yards! Thanks to all who have participated in this thread. I hope what I learned can help someone else. Brad is the patron saint of Scroll Saws. Thanks for your continuing help with these old gals.
Ron


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## MrUnix

> I removed the Secondary gear set from the spindle and found it's natural balance point hanging straight down to locate which tooth or notch was basically the Top Dead Center. It's a tooth, located at the center point of an Allen bolt (1 of 3). Now I could locate the corresponding notch easily on the motor gear, it's centered on the Allen bolt directly across from the majority of the cast Iron weight. These new balance points were about 5 teeth off from where the previous owner had marked the gears. Ding!
> -Renron


That was a pretty ingenious method of determining the gear alignment! You would think they would have had some kind of marking on the gears to assist in assembly. Your method above should be a big help for anyone who ventures into disassembly, and forgets about the gear positions! I'm kind of obsessive when taking stuff apart, marking locations, taking tons of pictures, bagging and labelling removed parts (and indicating the part number from the diagram so I know where they go), etc… I know it has saved my butt on many occasions when trying to put things back together, particularly on machines that spend a lot of time between disassembly and reassembly where my mind tends to forget the details.

Based on what others have written, it seems like just about any amount of magnets will work, as long as there is at least one to provide a signal to the sensor. Having the full 28 would be ideal, but not an absolute requirement as everyone has found out. It may throw off the speed display, but I personally never use or even look at it, and could care less what it says. No different than using one of the many other variable speed saws out there that lack a display, and just use the knob position to show relative speed. It doesn't take long to learn what speed you need for the task at hand, and seeing what that speed is doesn't make it any different 

I have found these to be really nice saws, particularly since you can find them pretty cheap on the used market, and even cheaper if the rotor is missing  I'd like to get one of those uber-expensive top of the line things, but just can't justify paying that kind of money when this one does everything I need and never leaves me wanting much more. Until I find a nice used Excalibur or similar, I'll just keep happily using my Delta:









(one of my latest scroll saw portraits)

Cheers,
Brad


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## havenocat

> Brad, A big Thank You for all your help. After wrestling with this machine for over a year, I can now claim victory!
> I purchased it from a man on Craigslist who said the speed dial just suddenly stopped working one day. He also claimed the fix was a light dimmer. Right…............ I purchased it for $50 and cleaned it up when I got home. It would run at either ~ 100 SPM or ~300 SPM then shake like it wanted to explode. I fashioned a new Speed Sensor Rotor using the hub from the broken bits of the old rotor. The gears were marked on the back sides for weight balancing. I used what I had and made a rotor with 21 magnets. (First Mistake) Installed Rotor and with same ~100 SPM or ~300SPM, shook like a wet dog. I used the gear aligning markings from the previous owner (Second Mistake)
> Bad Idea, shook like a wet dog. Almost a full year passed and I decided to either fix it or send it to the dumps. Moving this thing around in my small garage workshop is not fun. I decided to start from Zero and use the information in this thread as a starting point and not rely on what the previous owner had said and done. I removed the Secondary gear set from the spindle and found it s natural balance point hanging straight down to locate which tooth or notch was basically the Top Dead Center. It s a tooth, located at the center point of an Allen bolt (1 of 3). Now I could locate the corresponding notch easily on the motor gear, it s centered on the Allen bolt directly across from the majority of the cast Iron weight. These new balance points were about 5 teeth off from where the previous owner had marked the gears. Ding! One down one to go. I then rebuilt a new Speed Sensor Rotor with 24 magnets. A 2 1/4" hole saw will work but is VERY tight clearance on the sensor. The Circumference is 7" & 9/32" , which works out to a magnet every 9.3/32" , that s 9 point 3, thirty seconds of an inch. I wrapped masking tape around the circumference, overlapped it and cut it with a razor blade, removed the excess from the overlap and laid the tape on the workbench. Now I was able to mark each 9/32 plus a tiny bit on the tape. When finished I put the tape back on the wooden rotor and cut slots on my marks. Worked perfectly. Epoxied the entire thing overnight and installed it with my new marks on the timing gears. During this process I also tore a hole in the boot for the air production. I used some Shoe GOO to make repairs because it has worked well other times I have used it for repairs. I did try to add an innertube patch as I suggested, but that failed upon first use, it was too stiff. This is how we learn.
> As of today, it runs smooth all the way up to 2000 SPM. The readout seems to read correctly too. Another old tool saved from the scrap yards! Thanks to all who have participated in this thread. I hope what I learned can help someone else. Brad is the patron saint of Scroll Saws. Thanks for your continuing help with these old gals.
> Ron
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> - Renron


New user to this forum, attempting to post. Sorry if it gets messed up. I found Ron's post very helpful. I have the same model saw. It has been sitting for 15 years unable to work as I now realized due to the speed control wheel being shattered. The lack of a speed control apparently was also the reason for my saw blowing fuses. I JB Welded the plastic wheel pieces together. 









I discovered when I went to put it back together I should have marked the gear timing before taking it apart. Used Ron's directions to mark the gears. You will see that when you eyeball the center point of the allen screw with the gear tooth and look at the axle shaft in the background, its fairly easy to determine the tooth on one gear that is in the center, and the "v" between the teeth on the other gear that is in the center. I will attempt to post pictures here to illustrate this. 

















































Anyway when I put it all back together it worked perfectly, in balance, in control of the speed. It had never been able to run at slow speed the entire time I've owned it. Now it does, and I am so excited!

Tonight I am using shoe goo to repair the bellows. I use that stuff for fixing lots of things. It think it will be the perfect fix for this. I pulled the bellows out - required ripping the remaining piece of attached rubber - but that allowed me to clean it really well and roughen it up with sandpaper and apply shoe goo to both sides of it.


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## MrUnix

> Tonight I am using shoe goo to repair the bellows. I use that stuff for fixing lots of things. It think it will be the perfect fix for this. I pulled the bellows out - required ripping the remaining piece of attached rubber - but that allowed me to clean it really well and roughen it up with sandpaper and apply shoe goo to both sides of it.
> - havenocat


Yeah, Shoe Goo would be perfect. I used some waterbed repair glue, which based on smell and usage, is essentially the exact same stuff. Mine has held up for several years now of pretty hard use, and it doesn't look like it will fail anytime soon. I do have a tube of Shoe Goo handy though, just in case 

Cheers,
Brad


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## Jgilbert007

I had the same problem with a broken speed sensor rotor on my 40-601. Could not find a replacement. Therefore it was a challenge to fix. Mine broke into 6 segments. I removed the hub, reassembled the broken pieces in the correct sequence then epoxied them together and to the hub simultaneously and used a hose clamp to secure everything. I mixed more epoxy and filled the hollows on both sides of the rotor, let it all harden up then wrapped the rim with a few turns of packaging tape. Reassembled and it runs like new with no speed changes and no vibration.


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## bigblockyeti

My Grandpa passed away 15 years ago and he had the exact same saw and it's still sitting in his shop. Grandma is close to relinquishing some of what she should have divested herself of upon his passing but now most of the equipment that sat unmaintained for a long time is in rough shape. I think it was a very good saw when new but I have no idea how it might compare to newer saw? I'm still kicking myself for not picking up a like new RBI Hawk for $75, oh well.


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## MrUnix

Just wanted to follow up on the above post regarding Shoe-goo… I was working on cutting out some pieces for a wooden gear gizmo a few days ago, and my bellows stopped blowing air. I struggled through finishing up the cuts, and then pulled the bellows cover off to see what was going on… only to see that my previous fix with the waterbed rubber cement stuff had failed. It apparently is not the same, as it gets kind of opaque and stiff when cured. Anyway, I cleaned things up and went to town on it with some Shoe-goo, and things are back to working again. The Shoe-goo appears to be much more flexible, so hopefully it will last a lot longer than my previous fix. It can also be thinned with Naphtha, so I could put a thin 'skin' around the top portion inside and out. Time will tell, but for now, it sure seems like it's the answer to fixing those things.

Cheers,
Brad


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## Renron

The Sho-Goo repair has worked well and held up just fine on my bellows. The saw has been awesome and with time I'll learn all the tricks it has to offer. 
I could not have built this At-At Walker from Star Wars without it.
Thanks again to all who contribute to this thread.
Ron


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## RivenandHewn

I'm so happy to have found this thread. The 40-601 I just picked up looks like it's never been used. The seller told me he hadn't used it in years due to the speed control problem. I figured I could find parts and replace them. Big surprise when I found out how much the parts cost from epartsfortherichandstupid.com.

I was going to try your magnet fix, but then decided I'd try to fix the original. Anybody else try this?

I CA glued the parts back together, then filled the voids on the sides with epoxy. Then I'll chuck it up in the lathe and smooth everything out. Hoping this helps with keeping it balanced.

I did screw up, and put it together without the center hub. I'll have to ream out the hole and epoxy it into place.

Wish me luck!


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## RivenandHewn

Success!

I turned the rotor on the lathe, just enough to leave the outer edge smooth.

I then re-assembled the saw and gave it a test run.

Seems to range from 40 to 2000 strokes per minute.

The control doesn't react as quick as I'd like, but it's smooth.

I may need to check the clearance between the rotor and sensor due to the fact I sanded it. I may have to adjust the sensor once I get some feeler gauges.


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## Renron

R&H,
Most of us aren't as lucky as you. When we opened up our machines we didn't have more than 2-3 little pieces of the rotor left. Not enough to work with. So we made new ones. Glad the epoxy trick worked for you. 
With the gears and counterbalance weights swingin' around down there it takes a while to change speed. Be patient, I set a speed for the material I'm cutting then forget it. It may be a digital display, but it's totally analogue underneath.
Ron


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## RivenandHewn

Ron,

Thanks for taking the time to reply.

When I saw that the parts fit together so nicely, I knew I had to at least try to repair it.
I was all set to turn a new one on the lathe with the magnets.

Either way, I credit this thread to being the difference between fixing it, and junking it.


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## ballandcage

Hello Brad,

First off, thanks to Brad and everyone who has contributed to this post. Like many others I wander in here for the first time with my non-working 40-601. Hopefuly I can contribute something as I figure out what's going on my my old gal.

My tale of woe is a bit strange. It was a craigslist score. Lived indoors it whole live, saw little use from what I could tell. Saw, Stand, rolling dolly and hundreds of new delta blades in the packaging with the manual for $250. I would say the saw is in excellent to like new condition.

Got it home and worked fine, no issues at all. Ran it a few times and then I got very, very busy for 4-5 years.

When I had some time recently I went to go run it and as I turned the speed up it did not run and then immediately ran very fast snaping the blade. I did not have the time to really dig into it so again it sat.

Went back to it on another day, figured it perhaps was temperature related as it was cold in the garage that day? Same thing, left it alone again as I did not have time to investigate a fix.

Now I have the time and when I turn it on it simply does not run. Motor hums, thats it. Display powers on.

I read the entire thread (rubs eyes), and when I opened up the "gear box" I was expecting to see the bakelite wheel in pieces, however it is intact. :-o Much to my surprise. It was pretty clean in there, again this saw was very lightly used. I also checked the gap between the speed sensor rotor and the speed sensor and it was at ..010. The locking nut on the sensor was tight as well.

I talked with Steve Rhodes at Delta. He listened, but did not have any real answers. He did state that the speed sensor rarely fails.

Any advice on troubleshooting. I have a meter and know enough to be dangerous with it, but I am no guru. Thanks in advance.

Cheers


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## Renron

Dear Cheers,
Sounds to me like the grease in the motor has dried out and possibly the bearings are close to seized from lack of use and old age. I'd take the motor completely apart and re-grease the bearings, or replace them if they're the sealed variety. They're cheap! It's not that difficult if you take pictures of how it comes apart. Go slow, and lay all the pieces out on a towel in order of disassembly. Reverse order to rebuild.
Ron


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## MrUnix

The tech guy at Delta is right, those hall effect sensors are passive devices that will last virtually forever - so you are pretty much left with either the motor or the speed control board being suspect, and need to determine which one is the culprit.

AFAIK it has a 90V DC motor that is controlled by a PWM speed controller. I'd first try manually turning the motor a quarter turn or so and trying again, just to make sure it didn't stop on a 'dead' spot - rare, but can happen. If not, then I'd check the brushes and commutator for wear or damage.

With the simple stuff out of the way, I'd yank the motor. That will let you check the machines C-Arm to make sure it's not binding, and let you spin the motor by hand to see if there are any noticeable problems, like binding or crunchy noises indicating bearings. If everything checks out, then my last step would be to apply current directly to the motor, bypassing the speed board, to see if it will run. A 12vdc car battery or similar can be used. If the motor is good, it will spin slowly under reduced voltage. Just unplug it from the control board and use the +/- leads to the motor for testing.

If the motor checks out, then it's most likely the controller. Depending on your electronics skills, you could try to troubleshoot it. I haven't really looked at it, but it could have something simple on it like a fuse or thyristor that is blown. I guess you could also take it to an electronic repair place if you have one close by. If all else fails, you can probably replace it with a MC-60 or similar from a treadmill. You would lose the digital display, but that is pretty useless anyway IMO.

Cheers,
Brad


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## ballandcage

Thanks for the detailed suggestions. Started with this, plugging it in again and it started. :-o

I should note that everything spun freely with no stiff spots and seems very well balanced. Based on the previous owner I think it was well cared for and never apart. It has a Baldor motor, that I would be very surprised would have any issues, not that it couldn't.

There is a "slow spot" at very, very slow RPM, I will call it the bottom of the chug, chug. That goes away as I increase the voltage. Seems normal as this is the motor overcoming the part of the travel that needs less torque to rotate the assembly.

So what got slightly repositioned enough to make it run? I am guesiing something in the electronics does not like a certain spot between the speed sensor and the speed sensor rotor, or is it a gap issue? I did check the gap and it is at .010, +/- something very small.

I though to close the gap up a bit between the speed sensor and the speed sensor rotor? Open up the gap? Suggestions?

Two thoughs IMHO I will mention this in regard to the runaway issue and the wheels exploding.

1) I used a surface grinder years ago that had a very, very sensative potentiometer that controlled the Y axis feed. The slightest adjustment made the table feed very fast. It was not a bad pot, just very sensative and probably not the best choice for that machine.

2) Not knowing enough about electronics, although it might seem the potentiometer is the culprit on our deltas I think what is happening is this. For "whatever" reason we turn on the saw, then nothing. So we turn the potentiometer up and up and up and then whamo, it gooes from 0 to 2000 rpm and the speed sensor rotor shatters. Not sure if this is how it is happening or not, just a theory.

My question is to the guys who manufactured a new speed sensor rotor is, do you still have the no rpm to runaway speed problem.

So I guess I am up and running. Tell me what you think I should do. I wonder iif my speed sensor rotor does not have magnets placed equaly and thats why it did not start. Maybe my speed rotor was made on a Friday?

Your thoughts? Looking forward to making some sawdust again!

Thanks all again!


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## MrUnix

> My question is to the guys who manufactured a new speed sensor rotor is, do you still have the no rpm to runaway speed problem.
> 
> So I guess I am up and running. Tell me what you think I should do. I wonder iif my speed sensor rotor does not have magnets placed equaly and thats why it did not start. Maybe my speed rotor was made on a Friday?
> - ballandcage


When the rotor goes away, the machine runs fine - but the speed is all over the place. I've never had it not run, or heard anyone else say it wouldn't run because of that. And while the speed pot could be a bit wonky, I doubt it would cause a no run situation either. My guess was that the machine hit that rare dead spot on the armature that I mentioned (hence the suggestion to turn the motor 1/4 turn and try again). Since it's running again now, I would not worry about it a bit and just start using it.

Cheers,
Brad


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## aluchipawa

Hi, I'm new to lumber jocks, but this thread has been very helpful in finding out why my delta scroll saw wasn't working right. Like everyone else, it was the speed rotor! Just wondering if Brad can send PM me the instructions on how to get the old rotor off and fix it? 
Much appreciated! 
Marcus


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## MrUnix

> Hi, I m new to lumber jocks, but this thread has been very helpful in finding out why my delta scroll saw wasn t working right. Like everyone else, it was the speed rotor! Just wondering if Brad can send PM me the instructions on how to get the old rotor off and fix it?
> - aluchipawa


Welcome to LJ!
PM has been sent.

Cheers,
Brad


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## Renron

Marcus,
Please make sure you mark the tooth locations (ON the gears) to each other before disassembly. You may not have to grease the bearings, but most of us either greased or replaced the gear bearings anyway. As long as your inside anyway…
Careful of the bellows rubber, it's very easy to tear it as it's old and fragile. Take lots of pictures as you go. Once running well it's a fantastic saw. One of my favorite old tools I own.
Ron


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## Fixitphil

I'm the new newbie, great forum guys! One of my current projects is a 40-601 that needs some love and attention. The rotor is shattered, only half is left, can't glue it back together. So today I threw a few steel shavings on the remaining rotor parts, lined it up and counted the magnetized parts. See attached picture. Somehow it seems there are 13 'magnets' in a quarter, makes 52 in total. In this thread, I only saw people talking about having 24 or 28 gaps.

I was planning on making a simple rotor with these flexible magnets, cut it in thin slices and glue it on a makeshift wheel. But not quite sure if to go with 52 or 28 or 24.

Any thoughts on my 52 count?


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## MrUnix

> See attached picture. Somehow it seems there are 13 'magnets' in a quarter, makes 52 in total.
> [...]
> I was planning on making a simple rotor with these flexible magnets, cut it in thin slices and glue it on a makeshift wheel. But not quite sure if to go with 52 or 28 or 24.
> - Fixitphil


That is an interesting result. I guess the only thing we know for sure is that you need at least one magnet to make it work  I used 20 magnets as that was an easy number to use with my lathe index (had 60 index positions). The 24 magnet solution was chosen because that was how many came in the package. Rwood came up with the 28 number using another magnet (see post #8 above) to detect them, but accuracy may have been limited due to the size of the magnets being used. I know that using 20 and 24 works well, and I assume that using 52 would also (and probably even better if 52 is the magic number!).

As for the flexible magnets - if you are talking about the kind that refrigerator magnets are made out of, you can forget that idea - I tried it with zero success (See post #10 above). They do not appear to have near enough magnetic force to trigger the sensor. That problem is all but eliminated using rare earth magnets - to the point where the gap between the rotor and sensor is no longer critical as it is with the stock rotor.

Cheers,
Brad


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## Fixitphil

> As for the flexible magnets - if you are talking about the kind that refrigerator magnets are made out of, you can forget that idea - I tried it with zero success (See post #10 above). They do not appear to have near enough magnetic force to trigger the sensor. That problem is all but eliminated using rare earth magnets - to the point where the gap between the rotor and sensor is no longer critical as it is with the stock rotor.


Thanks Brad for your great input! I'll measure my 52 count a second time and then go from there. I saw your post about the flex-fridge-magnets not working. Since I already have some on my fridge, I might try them in a radial setting otherwise, I go with neodymium.


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## Renron

Fixitphil,
Try if you want, but we know what works from trial and error. Let us know how you make out either way. 
I am now using my say to cut plexiglas (overlayed with clear packing tape for lube) and it's a great saw.


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## uiuc_josh

Hello,
Hope this is close enough to topic. I have a 40-601 that has a busted top blade clamp (old quick set type missing the spring and lever). I cannot find anything that I can use or easily modify to serve as a decent top clamp. Any ideas on where I can find a replacement for this model? Thanks!

Josh


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## MrUnix

I was not aware that there ever was a quick-clamp type blade clamp made for the 40-601, and the stock machine doesn't have any springs in the clamp. The normal blade clamp is really simple though, and would probably be pretty easy to fabricate from hardware store parts if you can't find a aftermarket supplier. Main working part is just a socket head screw and a square washer. Here is what it looks like on the machine:










Note: I don't use the lower hold down, so the above shows my rigged method of getting air to the blade 

Cheers,
Brad


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## daveblev

brad….i had some trouble getting on the forum after not being on for a LONG time! but i finally got on! i sent you a message concerning my 40-601. same as everyone else….speed sensor wheel. i have a few questions, and would appreciate your assembly/disassembly instruction help. thanks!
dave


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## daveblev

....also, since i dont remember what year i bought this saw, does the serial number designate year of manufacture? the number is 87F27685. thanks!
dave


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## MrUnix

> ....also, since i dont remember what year i bought this saw, does the serial number designate year of manufacture? the number is 87F27685. thanks!
> - daveblev


Yes, that serial number indicates it was made in June of 1987.
(From the Vintage Machinery Wiki)

Disassembly instructions have been sent via PM 
-what a hassle sending PM's has become!!! -

Cheers,
Brad


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## daveblev

many thanks brad! i dont see it as showing up yet….but im sure it will soon! im doing a happy dance as i will be able to start scrollsawing again!
dave


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## MrUnix

They are messing around with PM's here due to a recent spammer… so things may be slow or broken. I had to go through some 2 step 'captcha' anti-spam filter which is new. If you don't receive it, or anyone else wants a copy, try sending me a PM with your e-mail address and I'll send it via e-mail as an attachment.

Cheers,
Brad


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## daveblev

id like to send a public thank you to brad aka MrUnix for taking time out to send me pms about my saw so that i could get it going again. its much appreciated!
dave


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## Brawler

Brad, what it looks like to me is a passive sensor (induction as you put it earlier) similar to what they used to use in ABS brake systems. This type of sensor is dependent on the gap between the sensor and the "tone ring". If that gap is too far the sensor won't work. If the tone ring is out of round or too much run-out then it may not work properly. The auto industry doesn't use passive sensors anymore because of this gap issue and reliability, they use an active sensor. If you want Google ABS tone ring to get ideas. You probably don't need magnets, maybe something that looks like a gear.

Good luck, I'm sure you will be successful.


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## MrUnix

> Good luck, I m sure you will be successful.
> - Brawler


Thanks, but you are bit late to the game 

Go back up and read the first few posts, particularly #16. A simple rotor with embedded rare earth magnets works perfectly.

Cheers,
Brad


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## Renron

MrUnix is correct. Many of us have tried different methods to revive our saws. We have found what works and what doesn't. 
Make sure to mark where the gears mesh @ locations before removing them as they are counter balanced .
Ron


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## daveblev

ok. an update! (kind of) upon removing the bottom cover on my saw, i found the sensor wheel in 4 almost equal pieces. i was trying to decide whether i should epoxy the pieces back together, or turn a new sensor wheel, insert magnets, and epoxy in the original hub. i decided to epoxy the pieces together for a starting place. as of last night, they have been glued back together, the hub reinserted and glued. my son is the gluemaster on this project. thanks TWB! then, a sort of washer was cut for the front and back of the wheel, made out of plastic. these washers were glued on both sides of the sensor wheel, and the whole assembly was then encapsulated with epoxy, in hopes of keeping the wheel from grenading again. if all this doesnt work for some reason, ill turn one on the lathe out of wood, and go from there! keep your fingers crossed for me that this works! ill post pictures of the glued up sensor wheel when i get it back from my son, and post an update as to whether it worked when i get the saw back together. as a p.s., because of brad's (MrUnix)flawless instructions, the disassembly process to remove the sensor wheel hub was a snap! thanks again buddy!


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## daveblev

one of the steps in MrUnix's disassembly procedure is to make alignment marks on the 2 gears before doing any diassembly. if anyone is doing this work, DONT FORGET THOSE ALIGNMENT MARKS! those gears are really fine toothed, and you'll definitely need them. anyone who has ever replaced a timing gear set on a car knows what i mean!


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## daveblev

here is the glued up sensor wheel installed. it works great!


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## daveblev

the sensor wheel in 4 pcs., and after being epoxied back together. if you zoom in on the wheel glued up, you can see some writing on it. those are plastic washers cut from a butter tub!


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## LAW

Hey MrUnix, Just joined so cannot send PM.

I just got a 40-601 Delta scroll saw and see that you have some instructions on this saw that you've been sharing with others on this forum. I already have 2 Instruction Manuals. One dated 10/20/84 and other 3/14/90. My SN is 87B66609. According to a previous post this indicates my saw was made in 6/2009. I got the saw used with the older manual so am not really sure of the correlation.

Any more info you can send to me would be greatly appreciated.


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## LAW

For MrUnix again.

The speed sensor rotor is broken into 4 pieces and the ball bearing on the outer end of the shaft is bad.I've taken it apart after marking the gears but would like to know if they were aligned properly to begin with.


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## MrUnix

Serial number 87B66609 dates it to February 1987.
(Delta S/N decoder ring can be found here)

How the gears can be aligned is discussed in a post up above (#73).

PM sent for disassembly instructions.

Cheers,
Brad


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## LAW

Nuther question. Removed the speed control module. There are two buss fuses in there. The one with the very low rating is blown. Any idea what size fuses are in there?

Also, idea why it may have blown? Hopefully something as simple as running too fast without the speed sensor rotor.


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## MrUnix

According to the documentation I have:

Fuse F-1 is a 2/10A SL0-BLO type 3AG., LITTLE FUSE P/N 313.200, Delta P/N 1344262

Fuse F-2 is a 4A SLO-BLO type 3AG., LITTLE FUSE P/N 313.004, Delta P/N 1344263

Cheers,
Brad


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## LAW

We're doing great.

Do you have the bearing numbers for the connecting rod? Only complete assembly shown in the parts list.

The write-up you sent to me refers to a connecting ARM. Is that the same as connecting ROD in the parts manual?


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## MrUnix

From what I pulled out of mine:

Connecting arm deep groove ball bearings (2)
Fafnir S1KDD (OD: 3/4", ID: 1/4", Width: 9/32")
Equiv: Timkin R4AZZ

C-Arm pivot tapered roller bearings (2)
NTN 4T-LM11710

Idler shaft bearing (1) (Motor side)
NSK 608Z
Idler shaft bearing (1) (speed control rotor side)
Unknown open needle bearing (no inner race)
Note: Can be cleaned/repacked unless damaged

Cheers,
Brad


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## LAW

By the way, Idler shaft bearing (1) (Motor side) NSK 608Z

Z denotes sealed bearing. One Z is sealed on one side, ZZ is sealed on two sides. The bearing number should be corrected to NSK 608ZZ.

Don't know why but searching the web I found prices for this bearing ranged from $1 to more that $20. I have no idea why. Local distributor has them for $10 - $12, right smack dab in the middle. Any comment?

Still confused your 
Connecting arm
C-Arm
and ref manual Connecting rod.

Are we talking about the same thing? Does the Connecting Rod have 4 bearings? 2 on each end?


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## MrUnix

The 608 is a common bearing used in skates - there are lots of really cheap Chinese made onies out there. Get your bearings from a reputable supplier, like Accurate Bearing and you should be fine.

Rod, arm… same thing. Call it what you want. It's the thing that attaches the motor to the c-frame (yoke) to make it go up and down. One bearing on each end.

Cheers,
Brad


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## LAW

*Progress report:*
As best I can figure, my broken speed control rotor has 25 magnetic poles, all of the same polarity. I carefully calculated the spacing for 25 poles and marked them on my replacement wheel. When through marking I counted and have 26 equally spaced marks. Go figure. Reviewing past comments it seems they found ranges from 24 - 28 poles. My conclusion is that it does not really matter. The factory must have had a way of calibrating the speed control electronics. I searched the PC board and cannot see any way to adjust it. My conclusion is that for our purposes, it does not really matter. Anything close will work.

I have some parts ordered and when I get them assembled I will see if it works. If so, I will attempt to post a picture of my work and go on from there.

It has been a real challenge but if it works as expected I may be able to make replacement rotors to sell for a reasonable price.


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## LAW

I have made a new speed control rotor and have it installed. Question on timing of the two gears. Yes, I marked where it was when I took it apart but an not convinced it was in the correct place.

What is the objective of the timing? Do we want the counter weights in sync, both up and both down at the same time or do we want them opposing each other? If I knew that I could work out the details.

Was able to find a 0.250 amp slow blow fuse but since the original was 0.200 should I switch to a standard fast blow type? Don't feel like paying twice the cost of the fuse to have one shipped.

Original fuse has leads coming off the end and soldered to the PC board. I will just use standard glass type and solder it to the original fuse end caps.

Next item is the blower. Instead of trying to repair the original, I have a small 12 VDC air pump from my car load leveling setup. I will figure a way to mount it inside the space of the base or simply mount it outside. I have a bunch of electronic wall wart power supplies. I'll use a 12 volt one and tie it to the power switch. Maybe. If too complex I'll just install a new switch.


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## MrUnix

The orientation of the gears is to provide counterbalance - if they are not aligned properly, the machine will experience excessive vibration. As already mentioned, if you want to verify they are aligned properly, Ron described a process of manually aligning them pretty well in post #73 above.

I doubt the slight difference in fuse ratings will make much difference, and would just run with what you have.

Cheers,
Brad


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## LAW

OK, I've got the saw running with new speed rotor but speed control not working properly. Starts slow then will speed up with a little surging as I advance the speed control knob. When I get to about 200, it increases speed but then seems to hold constant speed even though the speed knob is advanced and the digital readout shows increasing numbers. The speed seems to remain constant.

I have soldered the replacement fuse to the original fuse because I could not find one like the original one with attached leads. It is as stated above, .250 A


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## LAW

*GEAR ORIENTATION*
I assume that the weights should be both up and both down at the same time. If that is not correct, someone please let me know.
I used my dial indicator that I use to set my jointer blades. I set the motor gear at bottom dead center (BDC) then set the second gear the same way to BDC. Original marks on the gears were *NOT* in the right place.


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## MrUnix

> *GEAR ORIENTATION*
> I assume that the weights should be both up and both down at the same time. If that is not correct, someone please let me know.
> - LAW


Counter weights should be opposite each other so they cancel each other out. As mentioned, Ron did a pretty good write up of figuring out alignment in post #73 above. Here is a picture for reference:










Cheers,
Brad


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## TIMTIMTIM

Hi All,
I realize this original post was in 2014, but I found this site quite helpful as I tried to save my Delta 40-601 from the scrap heap. I replace the OEM control board with a Reliance Electric DC1 V*S Drive that I had reclaimed from e-waste. Once all the internal jumpers were correctly set, it worked like a charm. The particular model I used was a DC1-70G; however, I believe that several, if not all, of the DC1 series drives have an armature voltage of 90VDC when wired with 115V single phase AC. Here are a few links to some information on the DC1 controllers:

https://www.technicianmanuals.com/manual/reliance-electric/dc1-vs-drives.pdf
https://www.artisantg.com/info/PDF__52656C69616E63655F4443315F4D616E75616C.pdf

Attached are a few photos of the rejuvenated scroll saw.

The scroll saw also worked with the Bodine electric model 856 controller. Here is a link to some information on it.
https://www.bodine-electric.com/products/dc-controls/filtered-scr-dc-remote-speed-control/0856/


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## DrJimTim

I'm new here and have the broken rotor problem on my Delta 40-601 scroll saw . I don't think I can make a new one as some have done. Any chance someone has found a different solution or knows a way I can get one?


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## Renron

Dr. Jim,
I suspect that you CAN build a new rotor, it doesn't have to be that precise. You need a hole saw, drill press , wood,
magnets and epoxy. it's not that fineky of a process. Give it a shot, they're are a few different types made by others. pick one and try. You can do it! We'll help if you need it.
Ron


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## PlagueWoods

Resurrecting this thread with a new question and then some updated information.

First, big thanks to Brad and everyone else contributing to this thread. This has been immensely helpful in my journey to rehab my saw. Mine is a 601 from February of 85.

My question is about the speed sensor. My rotor was intact and the variable speed works. The problem is the readout is stuck on 7777. I'm an electronics novice. Somehow pulled a transformer lead out of the board during disassembly and managed to get it soldered back in correctly. Not sure where to look to troubleshoot this one.

Second I'd like to add updated information to the thread. A list of replacement bearings that is up to date.

*Rear C-Arm Bearings - Delta Part # 26*
Replaced with Timken 4T-LM11710 Tapered Roller Bearings
Paid $9.10 USD Each *x2*

*Connecting Rod Bearings - Delta Part # 113*
Replaced C-Arm(pin) side with Koyo B-57 Needle Roller Bearing 5/16"ID, 1/2"OD, 7/16"W
Paid $3.88 USD

Replaced Gear(Hex Cap Screw) side with NTN RA4ZZ Bearing 1/4"ID, 3/4"OD, 9/32"W
Paid $9.95 USD

*Gear Rod Motor Side Bearing - Delta Part #104*
Replaced with NSK 608ZZ Bearing 8mmID, 22mmOD, 7mmW
Paid $16 USD for set of 2 (Used one)

*Gear Rod Speed Rotor Side Bearing - Delta Part #126*
Replaced with NTN RA4ZZ Bearing 1/4"ID, 3/4"OD, 9/32"W
Paid $9.95 USD

Also Replaced Bearings in the Motor however I would assume this would be likely to change over different manufacturing runs.

Motor Baldor 1/6HP DC Frame 74

*Output side bearing*
Replaced with 6200ZZ 10mmID, 30mmOD, 9mmW

*Brush side bearing*
Replaced with 6201×1/22RS 1/2"ID, 32mmOD, 10mmW


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## bigblockyeti

Dragging this from the dead, I originally posted in 1/18, six months before I moved south during which time I couldn't retrieve grandpa's 40-601 as I was rapidly divesting myself of everything I could to make the move happen. Now one of my sons is showing interest in wood working and I wanted to get grandpa's saw now that I have room. An inquiry to my uncle has me less than pleased as it seems to have disappeared with no explaination. I have a line on a different one that looks to be in decent shape and wanted to see if anyone has regrets aside from the exploding speed ring about owning and using this saw before I check out the one for sale?


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## MrUnix

> I have a line on a different one that looks to be in decent shape and wanted to see if anyone has regrets aside from the exploding speed ring about owning and using this saw before I check out the one for sale?


No regrets here. In fact, in many ways, I prefer the Delta over the Hegner (Multimax 18VS) I recently acquired.

Cheers,
Brad


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## LAW

The small bladder for the air puffier ages, gets brittle and breaks. You would have to come up with something else. I used the small air compressor from a car load leveler system and a 12 volt supply.

Difference of opinion on the counter weighted gears. Posted explanation says to position them 180 degrees apart to cancel each other. I contend to put them both the same way at the top OR bottom of the saw stroke (I forgot which). My point is that they are designed to cancel out the weight of the blade arm. My thought is, why create a weight on a gear and then create a counter weight to offset the first weight? The mass of the arm is what is causing the vibration.

Also did some rework on the blade clamps but will not go into that unless you request help.

Lee
Midland MI


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## bigblockyeti

Does the stock saw accept pinless blades? I know they can be quite the advantage but I suspect I could modify the clamps to accept pinless blades if they do not already.


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## MrUnix

> Does the stock saw accept pinless blades?


Yes - it uses standard 5" pinless blades.

Cheers,
Brad


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## LAW

If you have an intact rotor, would you confirm how many magnets are in it and if the magnets are all the same pole or if they alternate. If all the same, which pole is outward?

Not sure if it really matters but it's been a long time since anyone posted that had an intact rotor. When I got mine all that was left was the hub. Someone before me cleaned out all the pieces.

Also much easier for you to document it while it is still in one piece. No telling how much longer yours will last.


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## bigblockyeti

If the rotor isn't intact, I won't be buying it, at least not for more than $25.


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## bigblockyeti

Well, I picked it up after confirming everything worked on it. The puffer works, the rotor is intact, speed control works great and it was reasonably clean. All I did was remove the three screws holding the saw to the stand to load it and put it back on when home. It cuts fantastic with a new blade but the blade that was installed when I got it has reversing teeth that wouldn't let the work hold tight to the table without pressing down too hard. I can only imagine this is to cut down on tearout but I've never seen a blade like this nor do I care for how it performed.


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## MrUnix

Nice get. You will find that the reverse tooth blades like you have, with the bottom 4 or so teeth pointed upwards, will significantly reduce tear out on the back side of your projects, and saves you from a lot of sanding. I only use reverse or FD ultra reverse blades when doing portrait work. You do have that hold down, which is there to keep the piece flat to the surface and keep it from jumping up - if you want to use it. I completely removed mine, as I find it just gets in the way and it's easy enough to hold the pieces down by hand. It just takes practice, and you really don't need to exert very much force - just take your time and let the blade do the work.

Cheers,
Brad

PS: Seeing your bike in the background reminds me that I need to go out and finish rebuilding the carbs on mine so I can get back on the road


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## Weird1

Brad, I just purchased a 40-601, SN 88E… for 50 bucks. It seems to be in great shape and responding to speed adjustments but I'd like to know how to keep the ole gal running for years to come. Would you mind PM me so I can get those disassembly instructions? I wish I had read through this blog before I bought this saw, but it looks so good!

Steve


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