P-P Questions, and Answers?

[keakap]

I've looked, and read, and searched and read again, and haven't found the answer to the GFI "problem" unless it is to either 1) use a GFI Breaker with a standard outlet, or 2) forget GFI altogether.
Did I miss something, or is that the way it is. No big deal if it is, imho, for I think I should have chosen a GFI breaker in the first place when I installed the new circuit dedicated to the Shopsmith. (I was in a hurry.)

I've read about the various users having gone through "Wes's Magic Calibration", and tho I feel for Wes, I appreciate the solution. A little bother, but a once in a lifetime thang, not so bad, methinks. I've got a little lo-speed chatterboxing myself, but I don't know if it's bad enough to worry about, so I'll delay calling Support for a bit and give Wes some breathing room before I bug him. (Mebbe it's just a matter of running in the belts a bit?)

Beyond those two things I have nothing much to offer other than a hearty "Wow!" for the Power-Pro. For various reasons I got the total replacement package, and total replacement time, from opening the box, through removing the old one, to install, plug-in and test, was about twenty minutes. Probably would've been quicker if I'd had help.

Goo---, no, GREAT JOB, Shopsmith!

Hope all the new P-Ps are running well now.

[charlese]

I've looked, and read, and searched and read again, and haven't found the answer to the GFI "problem" unless it is to either 1) use a GFI Breaker with a standard outlet, or 2) forget GFI altogether....

Your assessment of the issue is exactly what I have found. I tried three different 20 amp wall mounted GFCI outlets and had no luck what-so-ever! There was one that gave me a little more time before breaking, but the others blew immediately! The GFCI breaker in the circuit box works fine. In fact I have two of these and both circuits work with the PowerPro. I was saving $ when I opted for the duplex outlet rather than another breaker. Shucks! Worked for years until tried with the PP.

Glad you also like your new headstock, and interested to find it also has some low speed chattering. It is truly a very nice machine. My chattering is worse when using the bandsaw. Any other noises and/or vibrations seem normal.

[JPG]

Your assessment of the issue is exactly what I have found. I tried three different 20 amp wall mounted GFCI outlets and had no luck what-so-ever! There was one that gave me a little more time before breaking, but the others blew immediately! The GFCI breaker in the circuit box works fine. In fact I have two of these and both circuits work with the PowerPro. I was saving $ when I opted for the duplex outlet rather than another breaker. Shucks! Worked for years until tried with the PP.

Glad you also like your new headstock, and interested to find it also has some low speed chattering. It is truly a very nice machine. My chattering is worse when using the bandsaw. Any other noises and/or vibrations seem normal.

Cannot help but wonder what a 'flywheel' would do for all these varying load idiosyncracies. I do realize one would really 'muddy' the control feedback loop. Me thinks a slower response time would actually help. The load variations on all these different spt's have got to be Wes's nightmare!

[dusty]

Cannot help but wonder what a 'flywheel' would do for all these varying load idiosyncracies. I do realize one would really 'muddy' the control feedback loop. Me thinks a slower response time would actually help. The load variations on all these different spt's have got to be Wes's nightmare!

But isn't that what the control loop is there are]Question[/B]: When this happens does the operator have the ability to slightly alter the operating speed, attempting to find that perfect speed where the chatter quits????

[robinson46176]

This "minor" problem is one of the reasons why I decided to wait a little while to acquire a PP headstock. I generally avoid jumping into something super new that is a little complicated right up front. Let the little glitches get sorted out then jump in. I sort of hate that in this case because I have warm feelings about SS and want great success for them and hope the PP is their answer for it.
There were other reasons I decided to wait too. One is $$$$... I have been putting everything loose into the horse storage business and it will not be really showing a full profit until the first of the year. That is when all that I have spent on it will be paid back by it (we are full already) and at that point it can pay for a PP.
Another is that since the horse thing is consuming about all of my time right now the poor woodshop is only producing cobwebs. Still, it isn't a long term delay. I'm hoping to be back in the shop more regular in a couple of months. I think that my smallest chainsaw, a machete and a set of garden pruners should get me through the worst of the cobwebs.
I have to wonder how bad that "chatter" is? I would suspect that the PP's are being listened to very very intently at this point.

[nuhobby]

On another post I believe it was riottnerd or backhertz who compared the Power Pro control options with those of the original Teknatool DVR. The Teknatool had more basic choices beyond speed alone. He mentioned parameters in PID (proportional, integral, derivative) feedback systems.

Feedback control of servo-motors is a very mathematically sensitive subject. With more feedback-gain of the 'error signal', you usually get faster response time but greater risk of oscillations/instability. This is an oversimplification of what can be 4th & 5th order complex (i.e., real and imaginary) polynomial equations. And the equations are based on a nominal "plant" (i.e. motor) which can be a hugely varying beast with and without high-inertia loads on it.

I'm pretty sure when I called for my logic-setting changes with Wes, he had me reduce a gain factor and change another parameter. Hard to tell without any documentation. Anyway, those chatters that had been noted with sanding disks or bandsaws are real: I suspect on top of a nominal shaft speed of 900-1500rpm, you had about a 5-10 Hertz oscillation which whacks everything in a very audible manner. Those of us who complained could have heard the same thing with ear-plugs and ear-muffs at the same time. Not trivial!

I don't envy the design engineers! Right now I'm happy. But I could see a design change in the future to make things more robust. Maybe entering a field based on what is hooked to the spindle, along with desired spindle speeds.

[charlese]

...
Question: When this happens does the operator have the ability to slightly alter the operating speed, attempting to find that perfect speed where the chatter quits????

When using the bandsaw, I have tried 900 RPM and the suggested 950. even tried 1000. Don't want to run the bandsaw at 1050 (D). No change with the chattering when sawing a 5/8" curve if the 1/4" blade ever gets in a slight bind. This chattering is not minimal nor ignorable. As said earlier, the vibrations (we call it chattering) have been so severe as to loosen the drive hub on the aux. spindle. My temporary fix is to avoid and blade binding and rely on sawing relief cuts to give more kerf room.

I have also noticed a slight tremble/vibration when staring the PP at saw table speed with a blade attached. This happens only around the 900 range while the headstock is gaining speed.

Yes, I feel for Wes! Talked with him last Thursday about these issues while standing at the machine and running it. He said he had to do some math to figure this out and he had to get hold of another PP to use while he is on the phone. He called back the next day and said this would take a while - he is working on the problem. Wes took this week off.

Evidently the beta testers didn't try bandsawing tight curves.

However after all that is said - The PowerPro is a wonderful machine! It never slows while ripping either with the table saw or bandsaw. Other than the issues above, it is a smooth running, quiet headstock at all speeds.

[JPG]

When using the bandsaw, I have tried 900 RPM and the suggested 950. even tried 1000. Don't want to run the bandsaw at 1350 (D). No change with the chattering when sawing a 5/8" curve if the 1/4" blade ever gets in a slight bind. This chattering is not minimal nor ignorable. As said earlier, the vibrations (we call it chattering) have been so severe as to loosen the drive hub on the aux. spindle. My temporary fix is to avoid and blade binding and rely on sawing relief cuts to give more kerf room.

I have also noticed a slight tremble/vibration when staring the PP at saw table speed with a blade attached. This happens only around the 900 range while the headstock is gaining speed.

Yes, I feel for Wes! Talked with him last Thursday about these issues while standing at the machine and running it. He said he had to do some math to figure this out and he had to get hold of another PP to use while he is on the phone. He called back the next day and said this would take a while - he is working on the problem. Wes took this week off.

Evidently the beta testers didn't try bandsawing tight curves.

However after all that is said - The PowerPro is a wonderful machine! It never slows while ripping either with the table saw or bandsaw. Other than the issues above, it is a smooth running, quiet headstock at all speeds.

I be curious WHAT specifically is creating the 'racket'? The quill shaft? The idler shaft? The motor? Methinks maybe that varies depending upon what is being driven.?

[charlese]

I be curious WHAT specifically is creating the 'racket'? The quill shaft? The idler shaft? The motor? Methinks maybe that varies depending upon what is being driven.?

Me too! My guess is the motor is getting a bad message. The shafts seem to be running smooth. If they were at all loose, or capable of making a racket, they would do so at other times. "Shopsmith" seems to think it can be fixed by changing the computer settings.

[dusty]

I used to work on a system that used a number of servos. When these were all functioning properly the system emitted a very low level hum and that was it. But when the servos were out of adjustment it made a racket that was deafening. As the control loops were brought back into range you could just hear it as it got closer to the null range.

Now the PowerPro is no servo feedback loop but I suspect it is functionally similar and if not corrected is capable of doing damage to itself. I would not be running mine in the speed range where it flutters without some close and well documented communication with Shopsmith.