Belt noise

[solicitr]

Well, I've actually started making sawdust with my new friend, but there are a couple of things that bother me.

One is significant belt noise. It's definitely creaking rubber, not scraping or bearings, and the sheaves/speed control are just fine. The belts look good, neither worn nor cracked, and the tension is spec 1/8 deflection. I read in an old thread on the Yahoo SS forum that with an old machine (30 years in this case) I should apply belt dressing, because they've become dry and stiff. Is this correct?

2) Heat. How warm is too warm? I'm getting 'a bit more than lukewarm' at the top of the headstock, a long way from 'hot' but certainly not 'cool.' Is this the normal range?

3) Vibration. This really bugs me- with the sanding disk the unit vibrates to such an extent that an unattended miter gauge 'walks' along the slot. I realize that the SS isn't a half-ton of solid cast iron, but isn't this a bit much?

EDIT: I should add that it's the motor drive belt that's creaking, not the poly-V.

[dusty]

Being an old belt that has been idle for years I would expect it to be a bit stiff and possibly dry. You may be getting close to a belt change. I would dress the belt first to see if that helps.

My headstock runs warm. I recently reported a hot headstock here on the forum. Belt tension seemed to be the most common suspect. I have adjusted belt tension and it seems better. Get this, my belts were too loose. I assume the heat was from slippage. This subject came up last week at the TA and Rick Davis confirmed that too loose a belt may cause excessive heat.

What you are reporting doesn't seem excessive. Mine got so hot that I couldn't leave my hand on the headstock if I was working it hard.

A little vibration is normal and especially if you don't have all four legs firmly on the ground. I'd work on this. I'd start by stripping down to just the headstock (no blade, no saw guard, no auxillary tables, no extension tubes).

Make certain that all locks are employed and then run. If no vibration - add equipment incrementally until vibration starts. Last item added is suspect.

Please let us know what you find.

[charlese]

Dusty offered up good advice. I would like to add that from your post - it seems you have no vibration issues without the sanding disk. Therefor it is my guess your disk, or the sandpaper is the issue. Did you check to see if the disk is properly on the spindle? If so, remove the sandpaper and try with a bare disk/

After running a while in a moderately warm shop (60 to 70 F) it is normal to feel the headstock luke warm on the top side opposite the spindle.

[solicitr]

Thanks, guys. I went back out this evening and found a couple of things. One, I'm the culprit- when I tensioned the poly-V belt I foolishly moved it to have two grooves on each side, which would be I think correct for *some* Mk V's. But in fact on *this* one it's wrong and I angled it- and then compounded the problem by tensioning the slack side, so that the tight side was like iron. Moved it back- no more noise, no more heat. Incidentally the eccentric slot wound up back where it had been before I monkeyed with it in the first place.

The vibration is two separate issues. The big one is the (aluminum) sanding disk, as you guessed- it ain't flat. Ergo bad vibration.

However, there is still some slight vibration to be felt through the whole machine, even with an empty spindle. It's worst, unsurprisingly, at the tabletop, perched up there on two pipes. I didn't try the nickel test but I doubt it would pass. I suppose hooking it to the extension table with the tubes would tighten it up some.

Still, should the whole unit vibrate unloaded like that?

[paulmcohen]

You might get slightly more vibration out of a one bearing quill but I have never notice the kind of vibration you are talking about.

[charlese]

...However, there is still some slight vibration to be felt through the whole machine, even with an empty spindle. It's worst, unsurprisingly, at the tabletop, perched up there on two pipes. I didn't try the nickel test but I doubt it would pass. I suppose hooking it to the extension table with the tubes would tighten it up some.

Still, should the whole unit vibrate unloaded like that?

Bill - The quick answer to your question is NO! The machine shouldn't vibrate when everything is working properly. Did you receive your 2 bearing quill and install it yet? If so, and you are pretty sure it is in properly then look at - 1) the drive belt - Does it have missing pieces? 2) the sheaves - Are they complete, without broken pieces? 3)The two shafts - especially the upper one. Does it slide smoothly on the shaft when disconnected from the speed control quadrant? Does it wobble at all? Also check the lower shaft to see if the Floating or Fan sheave wobbles on it's shaft. 4) While you are at it check all sheaves for small cracks on the back side that could cause the sheave to wobble as it turns.

Since you have had the Poly V and drive belts off I assume you have checked both of these for any thing out of order.

[nuhobby]

Bill,

I have a 510 (fairly new) sitting on my basement's carpet. I have a minor level of vibration such that an unattended miter will gradually creep through the slot. Likewise if the (510's) finger-nuts securing the table-extension tubes aren't snug against either the tube or the table without tube, then these finger-nuts will rattle a bit. At the moment I don't recall exactly but these vibration modes may be more noticeable at intermediate shaft speeds.
I haven't been concerned; it may have something to do with my carpet situation (?).

Regards,

[solicitr]

Actually I haven't had the belts off- I just inspected them when I tensioned. They looked okay insofar as I could see. The sheaves are not broken, but I can't swear they aren't worn, loose, or otherwise problematical.

New two-bearing quill, tight and no issues.

I guess I'll have to gut the thing and check the sheaves, as well as try the shafts individually for signs of bearing trouble. Can I do this without pulling the motor-shaft spring (I hope)?

[dusty]

I think that it is good for you to be willing to tackle a teardown and rebuild of your Shopsmith. Once done you'll know what makes that puppy work or not work as the case may be.

However, I doubt that you are going to eliminate vibration. Very early in my Shopsmith experience I learned that you can not leave items on the table tops and expect then to remain while you are working. They will vibrate off. I often lay the allen wrench, a screw driver, a wrench, the tape measure on the extension table while I am working only to find them on the floor. Vibration shakes them off.

You said, in this thread, that your aluminum sanding disk was the cause. Do you still have a vibration issue with the disk removed.

You also said the motor drive belt was an issue but I thought that was a noise problem.

Does the forum support the theory that an old drive belt will cause vibration (assuming it is not cracked or have missiong pieces)????

[solicitr]

All right, Charlese tells me I should have no vibration, Dusty says some is normal. Which is it? I don't reckon the Mark V should be as motionless as a Unisaw, but how much is too much, as in a symptom of Bad Things?

To recap the issues:

1) Belt noise and heat- I blamed this on the drive belt, but it was in fact due to the poly-V being misaligned and mal-tensioned. FIXED.

2) Vibration I- due to warped sanding disk. FIXED by taking disk off.

3) Vibration II- much smaller vibration, cause unknown. May be old/damaged belts (incl poly-v damaged by me); or may be something else entirely.

NB it seems to me that a stiff/sticky motor drive belt could 'stutter' its way around the sheaves, causing vibration