All Replies on I don’t think there is an answer to this problem.

Don: I used to live in Vegas.
You have an accident waiting to happen I think. My solution is there is a large lake close by with lots of boats…..
Sounds like a bent shaft.

-- Don't rollerskate in a buffalo herd

I did and put a new belt on it. Since the pulleys are so small in dia. they get a set that can cause bad vibration. I replaced mine with “power twist link belts” from Rockler. Runs very smooth now. My saw is a 12” contractor saw about 30 years old. I hope this works for you.

-- Thor and Odin are the greatest of Gods.

Madts,
I have changed belts including a power link It didn’t work.
Howie,
Lake Mead is close but I can’t afford a new saw, otherwise this one would bo on CL or be sold as a boat anchor.

-- "Courage is being scared to death -- but saddling up anyway."

Check the amps that it is drawing Don if its high without a load its bearings. Sometimes the bearings will cause vibration when they dry out, sounds like your starting to experience bearing failure in the early stages. You can take it to a repair center which is cheaper than a new saw, do it soon before it spins the shaft.

I have a friend that owns this saw and it vibrated badly. We checked it out and it was the belt sheave. I don’t remember which one (motor or arbor) but I think he changed both of them and got a new belt while he was there. Just the regular V-belt. It is smooth today. I would look there then I would check for a bent shaft in the motor.

All good suggestions, thanks. The bearings seem fine and I can’t detect any bend in the shaft, although I don’t have a dial indicator to be sure. The strange this is that with just a little bit of support under the motor it runs smooth and quiet but when the motor hangs free it shakes. I’m thinking of removing the spring loaded mounting pins and just bolt the motor the mounting support to see if that clams thid thing down.

-- "Courage is being scared to death -- but saddling up anyway."

To isolate the problem, try taking the belt off and run just the motor. If it still vibrates you know where the issue is.

-- Happiness is like wetting your pants...everyone can see it, but only you can feel the warmth....

Thanks, knotscott I’ll try that.

-- "Courage is being scared to death -- but saddling up anyway."

Pulleys themselves may be out of balance. Perhaps the tension spring is a bit loose or soft…

Shaft can be checked with a simple jig to hold a small wire or nail up to the shaft as it spins – will give you some idea. The amount isn’t really important – just that fact that it may be bent.

Your saw might have the 2 piece arbor pulley. My 36-979 does. I’ve read complaints about it loosening and causing vibration. -Jack

Here’s what I did today. Took the belt off and fired it up. The motor ran smooth. Put the belt back on and removed the blade and there was a slight vibration but it is livable. Now I’m saying to myself, What the hey. I put the blade back on and the motor jumps all over the place. OK, I got a bent blade. Nope the blade is flat and true. I use the Freud blades and this is about the 10th one I have had on this saw in the past 5 years and I have always had this problem. So, I tried another blade of a different make, same problem. I put a full kerf blade on it that I check for flatness and the motor still jumps. The saw is the Delta 36-979 with the single pully on the arbo rand the nut is tight. I’m really at a lose here.

-- "Courage is being scared to death -- but saddling up anyway."

Since there is a slight vibration with the belt and no blade, perhaps the arbor is bent. Then when you install the blade, the small arbor wobble is amplified.

-- "Too much hurry ruins the body. I'll sit easy … fan the spark" - I. Anderson

That very well could be. If that is the case then I’ll just have to keep proping up the motor. Bummer.

-- "Courage is being scared to death -- but saddling up anyway."

get a better class of blade. Tenru, Ridge Carbide, Ghudo get a better class of blade.

It is hard to imagine it is not the blade/s
you took it step by step bringing the system on motor first then the belt and arbor and then finally the blade and you got no vibration until you add the last element – the blade – and that’s the only time it vibrates
What else is there but the blade?

You might try cleaning it

-- When the moderator chooses sides, his site sucks.

doninvegas – Put the belt back on and removed the blade and there was a slight vibration

cr1 – you got no vibration until you add the last element – the blade – and that’s the only time it vibrates

I do not follow.

-- "Too much hurry ruins the body. I'll sit easy … fan the spark" - I. Anderson

It’s very possible that all 13 blades I have either used or just tried are a little off. That and arbor being slightly out of round would cause the motor to jump around. I have used Freud, Delta, DeWalt and Forest over the years but I have always had this problem. When I say slight vibration with no blade I mean you feel the vib. but you can barely see it. I can live with that. After all it is a contrator saw I don’t expect perfection. I agree with cr1, what else could it be but the blade? I’m thinking of removing the spring loaded pins that hold the motor on and bolting the motor to trunoin. If that doesn’t work then I’ll just keep supporting the motor with a stick.

-- "Courage is being scared to death -- but saddling up anyway."

That’s odd, I have the same saw and haven’t had any issues yet. I use a power twist link belt. I get a tiny bit of vibration when it shuts off.

It certainly wouldn’t hurt to bolt the motor in place; just leave a bit of slack when tightening the nuts down. Also make sure to get the biggest bolts (diameter) that will fit, and don’t settle for hardware store junk. I’d get the bolts from mcmaster carr. They have strength ratings listed so you can pick bolts that won’t bend.

-- He who dies with the most tools... dies with the emptiest wallet.

I doubt it’s the blade. I run Freud blades almost exclusively, and I’ve never had an issue with any of them (which, by the way, is more than I can say for Tenryu). Seems unlikely that you would get 13 bad blades in a row and I’d get 20 or 30 with no issues.

If the blade arbor was slightly bent, you would get slight vibration with no blade … slight because the arbor is fairly light and small diameter. When you add a blade to the arbor, you’re adding a fair bit of weight and a bunch of diameter which means the vibration would increase exponentially.

My vote is a problem with the arbor.

-- http://www.peteroxley.com -- http://north40studios.etsy.com --

I’m agreeing with Peter. I don’t see how it’s the blade. I’ve used some old cheap blades before to rough cut lumber that I knew to have some nails in it and although it wobbled a bit, the vibration was limited to the blade itself and was never enough to cause the motor to actually fall off. If the motor runs vibration free and you’ve tried different belts then it seems like there is some problem with the arbor. And like he said, once you put a blade on it the vibration is going to be greatly increased.

-- It is amazing what you can accomplish if you do not care who gets the credit. - Harry S. Truman

Have you thought about the arbor being under size where the blade fits? This would allow the blade to drop down a few thousandths, then you tighten the nut and lock it in that position. Now when the blade turns it is not centered and it causes this vibration.

Clamp a straight edge to the table where the teeth touch the straight edge. Turn the blade slowly and see if it moves away or cuts into the straight edge then you would know the arbor is under size. ?? or bent….?

Well a “slight vibration” might be the belt but he’s played with belts so it ain’t the culprit: just a minor contributor
There’s no way in hell that putting a blade on a system so simple as that would exacerbate any little irregularities from the belt or pulleys. The blade is not an amplifier.
So I’m discounting the minor crap and looking at the Gestalt.

However one alternative to the blade comes to mind:
And it’s all your fault Chuck, for making me re think this – milli grazi

A flat spot on the arbor or an egg shaped arbor if one side of the arbor is worn away where the blade sits the blade might be out of center. That would definitely cause lots of vibration.

Check the arbor for wear spots visually and with a micrometer.

Try a spacing washer on the arbor to make the blade stand a little out on the arbor from where it normally rests.
It’s also possible that the arbor was ground imperfectly. In which case a mic will show the defect and you’ll just get a new one.

Which begs a question I don’t recall being asked: Has it ALWAYS done this?
When did it start?
To have the same effect with ALL your blades is really stretching the “bad blade” solution I should think.

-- When the moderator chooses sides, his site sucks.

cr1, In my last reply I did mention that this has been a problem since day one.
Grandpa, I did as you suggested. I layed a flat metal rule on the saw and raised the blade to where it just barely touches the rule and spun the blade by hand. Its’ been confirmed, the arbor is either bent or miss-shapen. I’ll try shiming the blade out a little and see if that makes a difference.
Thanks everyone.

-- "Courage is being scared to death -- but saddling up anyway."

Remove the blade and raise the arbor to it highest position. Then try to move the arbor by hand just wiggling it up and down and back and forth. The arbor bearings could be the problem.
Make sure the saw is unplugged.

-- Chief Petty Officer USN(RET) 1991-2011

I tried that. The arbor and bearing has no slop at all.

-- "Courage is being scared to death -- but saddling up anyway."

I’ve never changed one, but have read about many others swapping out an arbor…might be the cure here.

-- Happiness is like wetting your pants...everyone can see it, but only you can feel the warmth....

There was another LJ that had a problem with his stacked dado set. He finally found an undercut at the end of the threads where the arbor was smaller. I think he built it up with JB Weld and dressed it down. I think his chippers were higher than the blade on the side and the dado wasn’t flat in the bottom. This is somewhat like your problem.

mystery solved now it’s just a question of whether the arbor is still available

If it is not available one solution would be to have the arbor rotary welded and re ground.

-- When the moderator chooses sides, his site sucks.

http://www.ereplacementparts.com/
Looks like parts are available and cheap too. If I were to replace the arbor shaft I would replace the bearings as well. I have replaced several sets of bearings on several of the older Delta Model 10 contractors saws and they are pretty simple and straight forward. The design and parts break down for your saw is similar. I use aftermarket bearings that are much cheaper and more available than the factory ones.

Good advice. If you take it apart replace the bearings with GOOD bearings. Cheap insurance.

Good advice but, I bought this saw from Lowe’s 5 years ago during close out and paid $450 with the fence. Replacing the arbor and bearing will cost ??? …..plus my time and labor. Is it worth it? I can just keep supporting the motor with a piece of scrape wood and continue on as I have been. I was hoping that this wasn’t the case (bent arbor) but since it is I’m not sure I want to put any more time or money into this saw. I’m the only one that can make that decision. At least with the help of all of you we have gotten to the bottom of the problem.
Thanks again,
Don

-- "Courage is being scared to death -- but saddling up anyway."

Guaranteed it’s a bent arbor. There’s nothing wrong with 20 blades, maybe 1, but you states it vibrates with any blade.
What’s happening is the arbor/shaft is bent/eccentric etc. and vibrates a “little bit” without a blade.
Let’s, as an example, say the shaft is out. .005
Then you put a blade on it and that .005 carries out to the teeth of the blade (O.D) and is compounded to maybe .025 wobble/concentricity.
If it’s been doing this for years and has gotten worse, this condition affected the bearings over time.
Replace the arbor and bearings and it will probably run better than when it was new.

-- Government does not solve problems; it subsidizes them.

I think I would order the parts and set aside a day to make the repair. You can use the stick until you get ready then stop everything and do it. Bearings should be available at any store that sells bearings. The arbor will have to be ordered from the supplier.

I’d look at this way. The original money spent is really irrelevant to your path forward…regardless, the saw’s not right. You can spend $25-$40 and an hour or two of your time to can make it right, or you can shell out a lot more to get another saw that’s “might” be right. A new arbor looks pretty attractive to me. Now if you hate the saw, and want an excuse to get a new one, that’s a different matter!

-- Happiness is like wetting your pants...everyone can see it, but only you can feel the warmth....

oops, I guess I cloned instead of editing. Delete this please. Thanks. -Jack

Don, I thought about changing the 2 piece (split) arbor pulley on my 36-979 when I tuned it up. I had heard of of it giving trouble (vibration) due to it not seating correctly. I can only find one reference now. I had a balanced steel motor pulley and my saw doesn’t vibrate so I didn’t bother changing the arbor pulley. If you can’t put a dial indicator on it to see what is off, I’d swap that arbor pulley or at least remove it for a look. Might be the cheapest fix(gamble). Good luck. -Jack

Good bearings from Accurate Bearing are not as expensive as normal retail, run-of-the-mill bearings. Have you checked the face of the flange for run-out?

-- Dan Coleman, retired Welding Inspector and past IA Teacher

OK, at ereplacement parts it would cost $76 bucks for the arbor shaft and the 2 bearings plus shipping plus an hour of my time. That’s not bad IF that fixes the problem, which it should. I’m starting to save for a new saw so do I put this 80 bucks into this saw or put it towards the new one? I plan on getting a good hybrid saw because my shop is so small I need the smaller footprint. I have lived with this vibration problem for a long time and was hoping there would be a quick and easy fix that I was overlooking. If I save for the new saw I could then sell this one on CL and get some of my money back and of course I would give full disclosure to it’s problem. Now I have to decide what route I want to go.

-- "Courage is being scared to death -- but saddling up anyway."

$80.00 is cheap and it’ll make your saw re-sellable

-- When the moderator chooses sides, his site sucks.

Your saw would sell…..where $250 range but in the current condition it would sell for $50…maybe. Repair it then you might as well use it.

Don, Here is a long post from SMC . At the end (4pages) the OP fixes the vibration in his 36-979 by making backlash adjustments. Look on page 22 of your manual. Looks like a simple job – if this the problem it would save some money. -Jack

If you saw has a problem similar to the one refered to by IrreverentJack in #40, that might explain why it disapear with the piece of scrap wood supporting the motor.

However I don’t understand how this scrap wood support could cure a bent shaft problem.

So it might be advisable to check every adjustment articulation.

Otherwise for wobble you might be interested by http://woodgears.ca/saw_arbor/index.html

-- Sylvain, Brussels, Belgium, Europe - The more I learn, the more there is to learn

That fix sounds good and it would cost nothing to try it. I am always for those cures.

Hey it’s worth a try. I’ll check it out this weekend.

-- "Courage is being scared to death -- but saddling up anyway."

I thought I had it. When I checked the slop in the raising mech I could wiggle it a good 1/16 of an inch. I figured that was causing the vibration. Followed the directions and got all the slop out. Put the saw back together and fired that mother up. %#@* the motor still jumps. I guess I’m back to the bent arbor. Not sure what I’m going to do. Call me lazy but it would be a good bit of work to change it without disassembling the thing and turning it upside down. I’ll probably get a wild hair one day and do it but until then I’ll keep using the support. I have already lost a weekend and a half messing around. I need to cut some wood.
Thank s everyone for your advise.

-- "Courage is being scared to death -- but saddling up anyway."

It is possible that the pulleys are out of round or are loose on the shaft I had a problem replaced the pulleys and problem solved Andy

if the arbor was bent would not the blade show some wobble?......check for that.

-- In God We Trust