Shopsmith Forums

Imagine a speed increaser on the output of a Power Pro...yikes!

backhertz wrote:Imagine a speed increaser on the output of a Power Pro...yikes!

Maybe people would quit talking about the SS being to slow to use as a molder/shaper then.

SDSSmith wrote:Man, grasshoppers everywhere!!!!! .

You know they're not bad properly cooked. Might need a sauce to dip 'em in!:D

BPR

It seems that many here have not been "Kung Fu" followers and know little of Master Po and Kwai Chang Kane.

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New in 1997, Just used to reduce a 6' x 5' x 15' row of Pampas grass leaves to small chips, with great exerction and very little common sense.

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It would be free, but I just found the parts list to fix the SP drive, currently down to one wheel drive with a slipping belt, and 13 years cutting ~12,000 square feet. No mulch plug (fell out and got chopped up) no bag (not engineered for bag), blade adapter needs replacement, 5th sharpening of this blade, two more blades (NIB) and only uses 1/2 tank per cutting.

THis is not a sale or a thread hijacking. IT is a PowerPro.

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Yes, Beavis told me this was a good idea. Sorry. Now what if the PowerPro name is taken,,, More delays to rename IT.

Free to anyone w/SS, if available parts would cost more than original purchase price, BUT YOU MAY GET A WEEKEND OF WRENCHING TO REPLACE PARTS, OR BETTER YET MAYBE TWO WEEKENDS!!!!!!

This is not a sale or hijacking of this thread. It is a response on the availability of a PowerPro.

tomsalwasser wrote:Just got an email from SS trying to sell me a speed reducer for a couple hundred+++ bucks. Won't need it with a PowerPro, right?

I'd like to hear what more people think here. I just got a Power Pro but I'm not a bowl-turner.

My initial thoughts are:

Power Pro at high speeds is very strong. The table-saw mode is just great.

Power Pro at low speeds with Drill-bits is great, too. In fact it looks like the built-in speed-chart has more refinement (for several types of drill-bit, for instance) than the familiar printed Mark V speed-letter chart. I used the built-in speed selector and drilled some hard pen-blanks yesterday with uncanny ease, well-formed chips were just flying out of them. Worked great at 400rpm with a 1-1/4" Forstner bit, too.

Where Power Pro seems ambiguous to me is speeds < 1500 rpm or so, with a heavy large-diameter object like the steel sanding disk. The traditional Mark V has the induction motor in effect always trying to 'catch up' to a zero-slip speed, and never throttling itself back. The Power Pro DVR motor can do overshoot and undershoot speeds as it targets an exact desired rpm. Overshoot/undershoot isn't noticeable in many modes, but I see it happening with the big steel sanding disk -- even enough that there is sometimes some rattle coming from the rotational play between quill-shaft and drive-sleeve. I imagine that the DVR control algorithms to control everything from 250rpm to 10000rpm were very hard to design in the first place, not to mention accounting for drastically different inertias in the loads (compact drill bits versus heavy 12" disks). I'm thinking of trying a lighter aluminum sanding disk to see how it behaves.

In view of all the above: not sure about what a real Bowl Turner will say about the Power Pro. All other things being equal, I think a Speed Reducer would still help deliver big, slow torque to the large-diameter workpiece, while keeping the DVR motor in a comfortable operating spot for speed-control algorithms.

I have a question regarding this speed fluctuation with the sanding disk and in another forum, running the bandsaw. Does the fluctuation continue when a load is applied ie. when actuality sanding or cutting, or does the speed then stabilize? Curious.
Regards,
Dwight

drl wrote:I have a question regarding this speed fluctuation with the sanding disk and in another forum, running the bandsaw. Does the fluctuation continue when a load is applied ie. when actuality sanding or cutting, or does the speed then stabilize? Curious.
Regards,
Dwight

Would you please tell us which other forum is discussing the performance characteristics of the PowerPro?

nuhobby wrote:Where Power Pro seems ambiguous to me is speeds < 1500 rpm or so, with a heavy large-diameter object like the steel sanding disk. The traditional Mark V has the induction motor in effect always trying to 'catch up' to a zero-slip speed, and never throttling itself back. The Power Pro DVR motor can do overshoot and undershoot speeds as it targets an exact desired rpm. Overshoot/undershoot isn't noticeable in many modes, but I see it happening with the big steel sanding disk -- even enough that there is sometimes some rattle coming from the rotational play between quill-shaft and drive-sleeve. I imagine that the DVR control algorithms to control everything from 250rpm to 10000rpm were very hard to design in the first place, not to mention accounting for drastically different inertias in the loads (compact drill bits versus heavy 12" disks). I'm thinking of trying a lighter aluminum sanding disk to see how it behaves.

In view of all the above: not sure about what a real Bowl Turner will say about the Power Pro. All other things being equal, I think a Speed Reducer would still help deliver big, slow torque to the large-diameter workpiece, while keeping the DVR motor in a comfortable operating spot for speed-control algorithms.

Reprogramming the PowerPro could be a very difficult and expensive task if I understand its operation and programing. I believe the Shopsmith Speed Reducer would be an outstanding method/idea to overcome any low speed problems when dealing with any heavy inertias forces. Compared to the PowerPro headstock costs, a Speed Reducer is very reasonable. Plus, I believe most bowl turners would already own this unit so only a few bowl turners would need to buy the Speed Reducer if they found they had the need.

Also, since I believe many PowerPro owners will have another Shopsmith available in their shop, the Speed Reducer would serve that unit so it can do double duty and be worth any additional expense.

drl wrote:I have a question regarding this speed fluctuation with the sanding disk and in another forum, running the bandsaw. Does the fluctuation continue when a load is applied ie. when actuality sanding or cutting, or does the speed then stabilize? Curious.
Regards,
Dwight

Here is what I think I've seen:
- Speed fluctuations as such are not so much obvious in the working operation or the "rpm" indicator. I suspect -- if they are really there -- they may happen faster than you can observe, other than via this chatter sound in the upper spindle area.
- They can happen with or without a wood-sanding load applied on the steel sanding disk.
- For that matter they can happen whether driving the sanding disk on the normal quill side or on the opposite end of the machine. So I'm not 100% convinced the chatter comes from the quill-to-drive-sleeve slip-fit area. But I haven't taken the quill out to completely eliminate that possibility.