Powermatic 141/143 Owners HELP NEEDED

[Denis Hoshizaki]

I recently purchased a Powermatic 141 bandsaw for a dance. It powered up but squeaked, rattled and appeared to have some modifications done to it but for $200, it seemed like a worthwhile gamble. After cleaning it up, doing some adjustments, changing the belt and blade, it got the thing purring.

One of the modifications done to the saw was that on the lower wheel, someone appears to have drilled and threaded a hole to support a machine bolt in the hub. I've attached a couple of pictures, one with and one without the added bolt. I noticed that the small lock nut on the lower wheel was not tightened down. I got to thinking that perhaps a previous owner did the modification not realizing that the lock screw needed tightening. I removed the bolt during clean up, tightened the lock screw and got things running very nicely. I was amazed how quiet and vibration free this bandsaw performed.

After about five minutes to running the saw I noticed that a vibration started to generate and got progressively worse. After analyzing where it came from, i discovered that it was originating from the lower wheel which became loose. I noticed that the lock screw loosened itself and I retightened it. Starting up the bandsaw again, it was buttery smooth and quiet for about 5 minutes. Again, the wheel had begun to vibrate/wobble and the culprit was the lock screw loosening itself again. I went to the local hardware store and purchased a replacement lock screw hoping that a new one would remedy my problem but to no avail. I also tried some plumbers tape but with no success.

After a couple frustrating hours, I ended up screwing the modified bolt and washer back into the lower wheel hub and have got things working again but after 5 minutes or so of running, a slight vibration does return but does not seem to worsen and the small vibration seems to be almost livable.

I'm reaching out to see if anyone has any ideas to a fix to my problem short of finding a replacement lower wheel or drilling out the lock screw hole and putting in a larger lock screw.

Thank you for your time.

Denis

[Joe Jensen]

I don't think I understand exactly. Does the lower wheel wobble on the shaft? I used to own a 141 but no longer. Seems like all you need is a tight set screw to hold the wheel on. I don't see any purpose for that bolt in the end of the shaft. Is the shaft worn where the wheel sits?

[Paul Grodziak]

Denis,

What way does the wheel spin? The wheels on my bandsaw rotate clockwise. If the bolt was added by the previous owner, they might have neglected to notice that the wheel turns clockwise, and the bolt tightens in a clockwise rotation. Thus, every time you turn on the saw, the rotation of the wheel will result in the bolt unscrewing itself.

Best guess is you should be good with the set screw on the wheel.

[Dave Cav]

How tight is the lower wheel on the shaft? If it slides on very easily or is loose, that could be what is causing the set screw to work loose and may be the reason the previous owner threaded the end of the shaft for a bolt and washer. If the wheel is excessively loose on the shaft, the set screw will never hold by itself. Loctite makes products for locking loose pulleys and gears onto worn shafts so that might be an option but if the shaft is excessively worn then you might need the services of a machinist. Despite that, the 141 is probably one of the best 14" bandsaws ever made, and well worth repairing.

[Bill White]

Loctite red. It'll hold it well if ya clean the parts first. Acetone will clean all the gunk.
Bill

[Bob Coleman]

You might also try adding a second set screw behind the first to lock them in place.

To second the post above, on mine the lower wheel fits snugly on the shaft such that I needed a puller to get it off.

[Mark Bolton]

Id pull the set screw and see if you can feel any wobble between the shaft and the lower wheel. Your symptoms sound like that would be the culprit. Perhaps the set screw worked loose or kept working loose and the previous owner just kept running it and it created some slop in shaft/bore. At that point other than having the wheel bored and bushed you may try applying loctite or some other recommendation to the shaft itself, put the wheel back on, tighten both the bold and the set screw (loctite as well) as tight as you can, and leave it sit for a while. Then see what happens.

If I were faced with a repair here I think what I'd be thinking about doing is spotting an area around the factory setscrew large enough for a nut and installing a very long set screw in there with a jamb nut on it that seats against the hub of the wheel. I know the double setscrew is trying to achieve the same purpose but if I were trying to lock the slop out of the wheel without having it bushed (expensive) thats the route I'd try first. Spotting that area wouldnt not affect the wheel at all and perhaps with that, and the added bolt, you may get by.

[Denis Hoshizaki]

The lock screw loosens after approximately five minutes on run time resulting in vibration. By tightening the modified bolt, the vibration is minimized but not eliminated.

[Denis Hoshizaki]

The lower wheel has a very tight fit. I may give the Loctite product a try. Thanks

[Denis Hoshizaki]

Excellent suggestion and I believe I can secure a second lock screw behind the first. I will give it a try tomorrow.

[Denis Hoshizaki]

I tried the Loctite with no success. I tried the double set screw behind the first and it held for two five minute intervals. I added Loctite two both set screws and finally success. Thank you for all who responded. Thinking about doing a repaint.

[Bill Orbine]

Hopefully, the Locktite will help you and that the problem is eliminated. But I'd still be wary of this issue propping up again! If it does happen again, my suggestion is to replace the key. Wacky as it may seem, but this helped me on another machine! It's worth a try! And furthermore, I prefer Locktite blue versus the red.