Bandsaw and the PowerPro

wurlitzerwilly · Post by **wurlitzerwilly** » Sun Apr 29, 2012 7:57 pm

SDSSmith wrote:Upgraded my headstock to the PowerPro yesterday. Sucker runs very smooth and so much quieter than before. That is until, I mounted my old bandsaw. I set it up to resaw some 2x material and sure enough started hearing some intermittent knocking in the headstock. Enough knocking that it loosened the headstock drive hub. I checked alignment, power coupler fit and drive hubs. Locktited the set screws on the drive hubs. It does appear as though feedrate affects the noise. I will call Shopsmith in the a.m. to start the trouble shooting process.

I had hoped this issue had been solved by now.

I thought I'd cured the issue with a new coupler, but I was cutting some 4" stock and trying to get a very mild curve with a 1/2" sawblade, and the coupling came loose again, even though I'd used non-setting Loctite on the thread, at Shopsmith's suggestion. I also had a table saw blade mounted on the other end of the headstock (for stability) and the set screw came loose on that as well!!
The power coupling hub on the headstock does not come loose which means that it is possible for set screws to be secure under those conditions.
Having consulted engineering friends and woodworkers, I've come to the conclusion that there are several factors involved and the problem is unlikely to be the fault of the Power Pro, other than the fact that it is delivering more torque to the shafts and compensates very quickly if the load varies.
The problem seems to be associated with the bandsaw blade temporarily bogging down. I believe that firstly I need some new blades. The ones I have aren't especially dull, but they're old and not at their best. I also probably tried to take too tight a curve for the size of blade.
I've also ordered a newer style of coupling and hubs from a guy one eBay - #320595188050. It's also been suggested that I blind drill a hole in the shaft so that the set screw sits further in the hub, then there will be sufficient room for another set screw, driven down on top of the original as a locking device.
I'd be interested to hear if Shopsmith come up with anything else, especially any means of adjusting the Power Pro to smooth out the pulses.

jimthej · Post by **jimthej** » Sun Apr 29, 2012 9:32 pm

From another discussion and from some personal experience, I don't suggest having a table saw blade on while running the bandsaw.
I was cutting laminate flooring, crosscut on tablesaw rip on bandsaw. It worked, but I could tell it wasn't a good thing. Much longer stop times in both blades, surging on startup and long cuts. Having a sled for crosscuts and the fence for rips...priceless!

wurlitzerwilly · Post by **wurlitzerwilly** » Sun Apr 29, 2012 9:57 pm

jimthej wrote:From another discussion and from some personal experience, I don't suggest having a table saw blade on while running the bandsaw.
I was cutting laminate flooring, crosscut on tablesaw rip on bandsaw. It worked, but I could tell it wasn't a good thing. Much longer stop times in both blades, surging on startup and long cuts. Having a sled for crosscuts and the fence for rips...priceless!

I agree. It was only a test, but I should have had the disk sander on the headstock as it's heavier than the sawblade. There's not much danger involved using the sawblade as long as the guards are in place and the table's at the top of its travel.
I just built a sled for cross-cuts, but in this case I had to use the bandsaw as I was cutting half-blind mortises.

JPG · Post by **JPG** » Sun Apr 29, 2012 11:22 pm

IIRC SS recommends NOT attaching a 'flywheel' to the output shaft when powering a band saw. That was suggested here early on but is not now a recommendation.

Although a 'multi-function' machine, the Power pro is not programmed for simultaneous operations.

wurlitzerwilly · Post by **wurlitzerwilly** » Mon Apr 30, 2012 4:24 am

JPG40504 wrote:IIRC SS recommends NOT attaching a 'flywheel' to the output shaft when powering a band saw. That was suggested here early on but is not now a recommendation.

Although a 'multi-function' machine, the Power pro is not programmed for simultaneous operations.

They seem to change their mind as the wind blows.

One of their selling points is leaving the table saw blade on the headstock when the jointer's connected. Not as a flywheel, but for convenience.

michaeltoc · Post by **michaeltoc** » Mon Apr 30, 2012 7:03 am

dusty wrote:If I have followed this issue close enough, it seems to me that some users have solved this problem by replacing the power coupler with one that was tighter on the hubs.

While that may work, I have found that there is still enough backlash in the SS coupler to cause the banging noises. From my experience, the only two solutions are to use a rigid coupler (alignment is critical), or a call to Wes to learn how to adjust the settings.

The rigid coupler works great, but I prefer the convenience of the SS coupler. Also, I would get the banging noise while using the disc sander, so the only real solution is to adjust the settings. This eliminates the banging noise in all modes - and you can have the saw blade attached while using the bandsaw. The only negative is that the setting needed to stop the banging results in the "overspeed" issue that others have discussed. This is really not as bad as it sounds as it only happens at low speeds, and as soon as you put the PP under load the speed immediately drops to the set point.

dusty · Post by **dusty** » Mon Apr 30, 2012 7:12 am

This is a rhetorical question but are PowerPro users going to be forever dependent on Wes to tweak the software when ever something doesn't program exactly right?

If Wes (Shopsmith) is unavailable and something needs tweaking - are the users just up the proverbial creek?

michaeltoc · Post by **michaeltoc** » Mon Apr 30, 2012 8:09 am

dusty wrote:This is a rhetorical question but are PowerPro users going to be forever dependent on Wes to tweak the software when ever something doesn't program exactly right?

If Wes (Shopsmith) is unavailable and something needs tweaking - are the users just up the proverbial creek?

I only spoke with Wes one time, but I had to tweak the settings a few times to get it just right (fortunately I took notes). Perhaps I should post the procedure in a new thread?

wurlitzerwilly · Post by **wurlitzerwilly** » Mon Apr 30, 2012 8:16 am

michaeltoc wrote:I only spoke with Wes one time, but I had to tweak the settings a few times to get it just right (fortunately I took notes). Perhaps I should post the procedure in a new thread?

Yes, please do post the procedure. It would be invaluable. Obviously it would be at owner's risk and they should make a note of all original settings, so they can get back if they screw up.

It might be better if it was in this thread, so we can all find it easily.

It would be really helpful.

michaeltoc · Post by **michaeltoc** » Mon Apr 30, 2012 8:19 am

wurlitzerwilly wrote:Yes, please do post the procedure. It would be invaluable. Obviously it would be at owner's risk and they should make a note of all original settings, so they can get back if they screw up.

It might be better if it was in this thread, so we can all find it easily.

It would be really helpful.

Sure thing. However, this thread is quite long - it may be better if I start a new thread and call it "Adjusting the PowerPro Settings"