Shopsmith Forums

Thanks all - I rummaged around and found some thread lock and a couple of seemingly unused set screws ...so I will try that first.
Since I was doing it-i went thru all the other power coupler hubs on the tool as well-though I haven't had issue with the others (yet) .

b

A small hole and a cone point set screw would likely work. However I feel it should not be necessary to do so.

Bainin, are you running a PowerPro headstock, perchance?

Yes-its a PowerPro.

b

Aha! There have been several reports of couplers, set screws, etc., coming loose when running PowerPros. The DVR motor generate torque pulses while running, and those tend to loosen anything that can come loose. The bandsaw, being a high-inertia load, is apparently more susceptible to this issue than most.

I don’t have a PowerPro headstock myself, but some loctite on the prolem screws seems to be the usual solution. Other folks with direct experience can undoubtedly advise you better.

I had that issue with the bandsaw and the PowerPro. I tightened the set screw and there was no more issue. The hubs and the bandsaw drive spindle don't all fit together as tightly as they should and that might have been part of the problem.

The drive spindle for the saw is integral in the water pump bearing which is a generally standard size but may deviate from bearing to bearing, and the hubs have some variance also. At the slow speed of the bandsaw that DVR motor in the PowerPro is working like an impact hammer and it could certainly shake loose a set screw.

As already mentioned you may need a better set screw. I can't understand why there would be fine threaded set screws but it seems like some of them are. Or just use some locktite if needed. You might as well have a hub dedicated to the bandsaw that can be locked down and left there.

Make sure the alignment of the shafts is correct. A bit of misalignment causes the hub to "wobble" on the gears and can contribute to things coming loose.

edma194 wrote: ↑Sun Aug 08, 2021 9:29 am ...At the slow speed of the bandsaw that DVR motor in the PowerPro is working like an impact hammer and it could certainly shake loose a set screw...

Wow! Do you hear and/or feel something like that on yours? In what speed range? I do not. As I mentioned earlier, a small number of users seemed to have a large number of problems with the BS PP combo. One was using a speed reducer and running the PP faster. One was using a saw blade, I guess for a flywheel effect. Might have been the same person. Seems possible that some PowerPros exhibit way more 'torque jitter' than others. Also possible that some of what is attributed to torque jitter is something else.

- David

DLB wrote: ↑Sun Aug 08, 2021 11:16 am Wow! Do you hear and/or feel something like that on yours? In what speed range? I do not. As I mentioned earlier, a small number of users seemed to have a large number of problems with the BS PP combo. One was using a speed reducer and running the PP faster. One was using a saw blade, I guess for a flywheel effect. Might have been the same person. Seems possible that some PowerPros exhibit way more 'torque jitter' than others. Also possible that some of what is attributed to torque jitter is something else.

- David

At bandsaw speeds for wood you won't notice it but it's still happening when the saw is under load. Slow it down to the minimum speed and you can definitely feel it. This is not major banging described as an early problem with the PowerPro and bandsaws, it's just inevitable if you want that motor to run at such slow speeds under load. Even if you don't readily feel the vibration I'm sure it's enough to loosen a setscrew that is not tightly compressed into the threads.