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Need advise on 18 yr old Unisaw tune up

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Forum topic by irish620 posted 04-04-2012 03:56 AM 4580 views 0 times favorited 19 replies Add to Favorites Watch
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irish620

37 posts in 1775 days


04-04-2012 03:56 AM

Jocks,

I bought a used ‘94 Unisaw 36-812 off of CL for $750 last week ( Good Price ? ). Saw is in nice condition, very moderate use it seems. But there is a vibration that caused me to take off the top to explore and deep clean as well. The saw was used very little for the last 10 years ( idle for most of that ) but here are some things I have questions about :

1. The belts have a “SET” now, but are in good shape, I put more tension on them but I can still see some slop when the saw is running. Less vibration when they are off completely. Are some “set” belts set for life ? Should I replace them anyway ?

2. While spinning the arbor, it sounds a little rough (gritty ?), no discernable noise, just not silent. I marked the top with a sharpie and it doesn’t spin a complete rotation. Should I replace them ?

Overall the saw isn’t loud, just making some vibrations. I’m starting to critique it so much that I’m not sure if I’m just creating something out of nothing. I’ve Operated lots of cabinet saws in the past but never had to do maintenance on them. Now I want everything to be just right on my own saw !

Thanks————you Guys are the best !


19 replies so far

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Scot

344 posts in 2863 days


#1 posted 04-04-2012 12:03 PM

It would be well worth your time to go ahead and replace the bearings and belts. Don’t buy the bearings from Delta though, pull the old bearings and take take them to your local Timken bearing supplier, they will be able to match them with a higher quality replacement for less money, just make sure they are the sealed permanantly lubricated type.
Belts can be bought at the local auto parts store.

99% of the time this is all that’s needed to bring a Unisaw as young as your’s back to life. If you do need to replace bushings and crush stops, Delta doesn’t take you to the cleaners and the parts are usually readily available.

Depending on which fence came with the saw, that’s either a fair deal or a really great deal. Either way, this should be the last saw you ever have to buy ! Which in my opinion makes it a great deal !

Don’t let an overhaul of this saw intimidate you, you’ve already done the hardest part by lifting that darn heavy top off !

-- If the old masters had power tools, they would have used them. So get off your damn High Horse.

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irish620

37 posts in 1775 days


#2 posted 04-04-2012 12:48 PM

Scot,

For $750 It came with 50” unifence, which does have many pros over a BIESEMEYER, a mobile base, 4 inserts and a unattached Delta sliding table attachment ( which has mixed reviews, but should be worth cleaning and attaching ). The sliding table is what started the whole process of tearing down the top, then I said ” while I’m in here”.

It appears to me that despite the lack of wear and tear on the machine, the bearings and the belts are just feeling the effects of time. Will these items eventually be replaced regardless of use ?

The motor spins pretty nice and fluid without the belts. Since the motor is protected and covered, I’m assuming motor bearings can last a very long time. Do you have any opinons on this ?

I’ve read a lot of threads on belt replacements, some say link or ax cogged belts or matched belts….....what is your take ?

Thanks Scot for your help….....my wife isn’t really up on her machinery these days.

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Scot

344 posts in 2863 days


#3 posted 04-04-2012 01:56 PM

First off link belts just don’t work on the unisaw. Way to much torque, which snaps them.

I agree with you about the effects of time, the absolute worst thing for any machinery is to sit idle for extended periods of time. There is a good chance that the bearings have flat spotted after sitting idle for so long.
As far as the belts go, I always replace all three. They aren’t really that expensive and a lot easier to change while the top is off and they last forever.
One thing I have always said about the unifence is that it will turn a cheap saw into a good one. Having used both the unifence and the biesmeyer I can’t say which I like the best, in my opinion they are the best fences made for function, ease of use, and alignment ( the unifence is by far the easiest to align). Having the unifence makes this saw a very good deal.

With an overhaul your saw will perform like new and last for generations.

BTW what size motor does your saw have?

-- If the old masters had power tools, they would have used them. So get off your damn High Horse.

View Rick  Dennington's profile

Rick Dennington

5183 posts in 2661 days


#4 posted 04-04-2012 01:57 PM

It sounds to me like you just need to run the saw a while and “get the kinks out”....If the saw has set for a good while, and not used too much in the last 10 or so years, and if you don’t hear any bearings “squalling”, or belts slipping, or anything really unusal, I’d say it just needs to be used….Things that tend to sit in one spot for a long period without moving or being turned (as in the bearings and belts) need to be used….Example: If you didn’t move your auto or truck for a long, long time, then the tires looses air, they develop a flat spot where they’ve been sitting in the same position, etc. Everything gets “stove up” so to speak from just sitting there…..I’d run the saw and use it, cut some wood, and give a listen…..You can tell more about a piece of machinery when it’s running as to when it’s not…..Then if things develop that can be fixed or replaced, then by running it and using it, you’ll know more of what needs to be done, if anything…....

-- At my age, an "all--nighter" is not having to get up and pee...!!!

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irish620

37 posts in 1775 days


#5 posted 04-04-2012 02:32 PM

Scot, 3 hp …..right tilt. I did want a left tilt but it’s been slim pickings around here lately and I thought if I can de- rust the delta sliding table attachment, then it would actually be safer than having the left tilt. Sliding table got bad reviews but I’m hoping it will do the job well. Does cost $400 new.

How much spin should an arbor have when spun by hand ? I can’t even go one revolution.

Rick, I was going to just start cutting lumber but ….. I have to attach the sliding table, which means taking off the side wing. Then i thought I should do a deep clean and examine all the parts. It is a good learning experience. Now I just need the experience of knowing when to replace parts. Do you think the belts will loose their set if I just use it more ?

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Rick Dennington

5183 posts in 2661 days


#6 posted 04-04-2012 02:51 PM

irish620:

I have 2 saws…..a 5 hp. Unisaw, and an old Craftsman 3 hp. that I’ve had for 28 years…I’ve never did one thing to that saw except put oil in the motor when needed….It’s still got all the original parts and belt, and it runs good…...Original belts are usually replaced by then, but I’ve had no need to….but it don’t sit idle, either….Ran alot…...It’s hard to say about the belt on yours…Like I said, run it for a while, and don’t do anything to it till you hear unusal noises (if you do..?). A replacement belt is cheap at any auto store…O’Reilly, AutoZone, etc….Just take your old belt when you go to get the right size….Use it first….But…for piece of mind, you can change the belt before you use it…...if you want to…...

-- At my age, an "all--nighter" is not having to get up and pee...!!!

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Scot

344 posts in 2863 days


#7 posted 04-04-2012 03:10 PM

The arbor should spin freely. Not getting a full revolution is not good.

The 3 HP motor is a good one. There are some Unisaws 1.5 HP motors on them and they aren’t any good at all.

Overall you still got a good deal on the saw. If everyone realized how easy and inexpensive an overhaul on the Unisaws and Powermatics is there would be a lot fewer used ones around !

It usually costs me about $300-500 to completely overhaul/restore a unisaw, the older ones (50’s and 60’s era) get a little more expensive due new motor prices. That includes locating and buying either a used Unifence or Biesmeyer fence to put on it and rebuilding the motor. The fence and motor are by far the biggest expense. Bushings, bearings, belts and crush stops run about $125.
You are already ahead with a good motor and fence. So for less than a $1000 you will have a saw that runs like new about half the cost when it was bought new at about $2000.

Today the new Unisaw cost $3000-3500. I know, because I finally broke down and bought a new one last year.

So the little bit of time and effort to put into making yours perform like new will be well worth it.
The only problem you may have is when you are done someone will come up and offer you a bunch of money to buy it from you. Then you have to start over LOL.

That’s why I finally bought a new one. No reasonable offers on it yet!

-- If the old masters had power tools, they would have used them. So get off your damn High Horse.

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Scot

344 posts in 2863 days


#8 posted 04-04-2012 03:21 PM

BTW I almost forgot about the sliding table. New ones start around $650 and go way up. I would really look into rebuilding that one. It’s one of those tools that you either absolutly love or hate. If it turns out to be the latter you can always box it up and send to me LOL.

-- If the old masters had power tools, they would have used them. So get off your damn High Horse.

View Randy Woodworker's profile

Randy Woodworker

62 posts in 1796 days


#9 posted 04-04-2012 03:38 PM

Repalce the bearings. That will remove all doubts and give peace of mind. Takes less than an hour. Here’s a few tips (I just finished doing this a few months ago when I bought my used Unisaw for $225 – gloat).

Remove the nut at the back end of the arbor. There is also a large thin nut on the back end that contacts only the outer race of the back bearing. It holds the back bearing up against the casting. It requires a spanner to remove, but careful tapping with a punch can get it off. Careful though, it is very soft metal.

Tap the arbor out but tapping on the back end towards the blade end. Be sure the set screw on the pulleys is backed off. The arbor will come out, leaving the back bearing behind. The front bearing will still be on the arbor. Note the position of the spacers on the arbor shaft.

You will need a bearing puller to get the bearing off.

Clean up the arbor shaft to remove any gunk.

To mount mount the new front bearing on the arbor, put the arbor in the freezer for 30 minutes and the front bearing in the oven at the lowest temp you can (must be less that 200F). After 30 minutes, the bearing will slip right onto to arbor. Let it sit thereuntil the temperatures stablilize, and it will be then be locked in place.
Reassemble the arbor components as before. Set the rear bearing up against the casting and by tightening the rear nut (not the skinny one), it will pull everything together tight. Retighten the pullet set screw and install the skinny retaining nut and you are done.

Download the parts diagram from Delta and review it so that you know the basic arangement before you start.

Belts are nothing special. Just get three good quality ones, about 10 bucks each.

View Grandpa's profile

Grandpa

3256 posts in 2142 days


#10 posted 04-04-2012 03:50 PM

When a tool has more than one belt on it (like 2 or 3 running side by side) then they should be bought as a mathced set. I don’t think any auto parts store will have many of those. They should be bought as a matched set of 2 or a matched set of 3 and installed as a matched set. It will usually look like one of the belts is longer but that is still the correct way to do it. I woul go ahead and pu in new bearings. they are too cheap to not change since you are there. I would turn the motor on and let it run for a couple of hours while you are messing around sweeping the floor or something. It will redistribute the lubricant and make it run smoother.

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irish620

37 posts in 1775 days


#11 posted 04-04-2012 04:50 PM

Thanks guys !

I will replace the bearings and belts since I am already half way there ! For $50, I think that it is a cheap investment will give me a piece of mind for years to come. Hopefully it will take care of the vibration as well.
As usually the advise on replacing belts in varied. I think I’ll see if the bearings supplier has any thoughts on the subject.

SIDE NOTE :CHECK OUT the Pics of this 1948 Unisaw I just picked up as well:

I got it for $250, i am 3rd owner and the motor still runs with 2 original belts. Hopefully i will cut my restore teeth with this one. Have any of you guys used electrolysis before ? Ive been reading about it and it looks like it does wonders for old paint and rust !

View Scot's profile

Scot

344 posts in 2863 days


#12 posted 04-04-2012 05:26 PM

Great looking saw. I’ve started with much less! Very surprising to not only see that it still has the motor cover but in great shape too !
Even the blade shroud is still there.
Can’t waite to see pics of the finished project !

-- If the old masters had power tools, they would have used them. So get off your damn High Horse.

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irish620

37 posts in 1775 days


#13 posted 04-04-2012 05:45 PM

Scot,

Have you used electrolysis before ? or do you think a good wire brush cleaning will do the trick ?

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Scot

344 posts in 2863 days


#14 posted 04-04-2012 06:48 PM

No I haven’t, Soda blasting works fantastic, before I had that available I’ve always sanded.
As good of condition that saw is in, I would check around and see if you can find someone with a soda blaster.

-- If the old masters had power tools, they would have used them. So get off your damn High Horse.

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Grandpa

3256 posts in 2142 days


#15 posted 04-05-2012 02:26 AM

On the table you can put a few layers of towels on it then saturate them with white vinegar. Leave them overnight and check to see how much of the rust is gone. The cabinet is another monster. For electrolisis you need a tank large enough to submerge the top in. There are some good article on LJ concerning this. Bertha built a very nice setup with pics and plenty of illistration a few months back. That top really looks pretty good to me. It just needs minor cleanup and it will be in very nice shape. I don’t think you will regret changing the bearings while you are in there.

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