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PowerPro repair - First and final thoughts -

Posted: Thu May 30, 2013 2:04 am
by charlese
I Love my PowerPro!:) Guess I've seen about most of the things that can go wrong with it. Still it's a Beauty of a machine!!!

Last week the control module fell off (except it was held on by the plugged in cable). My first thought was - Why me?? After all this was my second re-build. Well, since it was only a year old there should be a warranty. Yes, of course there is! Probably the best warranty around for wood shop equipment. Second thought was to call Shopsmith, but it was already 3:30 PM Pacific time.

Knowing that my alternatives were either to send the whole unit back for another re-build or to get a new control panel and install it myself. The self installation seemed like it would be the least troublesome of the two.

I found the headstock would still work if the panel was plugged in. I called Wes at SS and left a message and also wrote an e-mail describing my problem. The next morning I got an e-mail from Wes saying they were packing up a new control module and it would be shipped ASAP. Good News!!!

Got the control unit on Thursday late and it took all day Friday to completely dis-assemble the PowerPro and then put it back together. The only part I could leave in were the spindle, because I also replaced both belts. Man! - it was harder to dis-assemble than to assemble. (Good thing my first unit was a DIY - I had some previous experience with the parts.

After all was said and done my final thought is: it works even better than before.

Here's some pix.
Back of the control unit. The two plastic screw posts broke off. Maybe they were tightened too much. I had put scotch tape on the lower post to hold the pieces together.
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This is where the control came from - Notice the two screws are still in the case. There wasn't enough room inside to remove them.
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This is how I operated for a week while waiting for the new unit.
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Posted: Thu May 30, 2013 11:15 am
by fredsheldon
My control is loose, has been since I installed it. It hasn't got any looser and I suspect I have punched the buttons on it a thousand times to date. Is this better than being too tight and running the risk of pulling the screws out.

Posted: Thu May 30, 2013 11:35 am
by dusty
fredsheldon wrote:My control is loose, has been since I installed it. It hasn't got any looser and I suspect I have punched the buttons on it a thousand times to date. Is this better than being too tight and running the risk of pulling the screws out.

I would pose that question with Shopsmith.

The plastic posts, into which those screws go, don't appear to be all that stout. Constant movement will take its toll.

Posted: Thu May 30, 2013 11:40 am
by charlese
Don't know if it is loose because the screws are loose, or because one of the plastic posts is stripped/broken. Only time will tell:confused: !
Sadly, the only way you can check this is to remove the motor and power module, which requires removal of the headstock locking assembly and disconnecting all the wiring including the power switch.

I hadn't noticed any looseness until the thing tried to fall out.

In a note written on the invoice of my new control, Jim McCann cautioned about over tightening. Just snug the screws.

Posted: Thu May 30, 2013 11:53 am
by dusty
charlese wrote:Don't know if it is loose because the screws are loose, or because one of the plastic posts is stripped/broken. Only time will tell:confused: !
Sadly, the only way you can check this is to remove the motor and power module, which requires removal of the headstock locking assembly and disconnecting all the wiring including the power switch.

I hadn't noticed any looseness until the thing tried to fall out.

In a note written on the invoice of my new control, Jim McCann cautioned about over tightening. Just snug the screws.
I think you might already know why!

Posted: Thu May 30, 2013 12:10 pm
by charlese
dusty wrote:I think you might already know why!

Yes, I do! Glad that the unit that broke was installed by Shopsmith in a complete re-build, and not me.

I noticed the two holes to accept the control unit screws were originally used to attach the speed control bracket. They still had threads in the holes that caused the new screws to bind. I'm thinking the binding caused crooked installation and stripping of the plastic holes. Anyway, I reamed out those holes in the headstock case before installing the new unit.

Posted: Thu May 30, 2013 12:35 pm
by dusty
charlese wrote:Yes, I do! Glad that the unit that broke was installed by Shopsmith in a complete re-build, and not me.

I noticed the two holes to accept the control unit screws were originally used to attach the speed control bracket. They still had threads in the holes that caused the new screws to bind. I'm thinking the binding caused crooked installation and stripping of the plastic holes. Anyway, I reamed out those holes in the headstock case before installing the new unit.
I hope that does the trick and this controller last for many years.

The plastics that they manufacture and use these days are phenomenal. They are not like the plastics of old. But, like everything, when misused they fail more quickly. Without some controlled testing, this is all subjective.

Posted: Thu May 30, 2013 1:16 pm
by fredsheldon
charlese wrote:Don't know if it is loose because the screws are loose, or because one of the plastic posts is stripped/broken. Only time will tell:confused: !
.
It's loose because I didn't tighten the screws very tight like my instructions suggested. It's just a slight wobble and I don't think it will cause excessive wear on the post, at least I hope not:p

Posted: Thu May 30, 2013 2:46 pm
by frank81
fredsheldon wrote:It's loose because I didn't tighten the screws very tight like my instructions suggested. It's just a slight wobble and I don't think it will cause excessive wear on the post, at least I hope not:p
Just a thought here.

The reason they don't want you overtightening is because the screw is "self-tapping" the plastic pilot hole. Once it bottoms out, continuing to tighten is just mangling threads and will make it looser and fail quicker.

The keypad has you pushing buttons at a downward angle, and the two screws are positioned vertically. Over time, pushing buttons is pulling on the top post's threads and trying to bend the bottom post (which is what happened to charlese's part).

If you wanted a snug fit and max life, tightening per the instructions like Fred has done and adding a foam seal/tape between the headstock and control housing would work. The foam would absorb button smashing before the plastic posts.

Posted: Thu May 30, 2013 3:20 pm
by fredsheldon
May not be very pretty, but couldn't you drill several new holes from the front side and tap new threads in the headstock and just install some long screws from the front?