Shopsmith Forums

I am in the final stages of the Power Pro upgrade on my 520. I followed the video and everything has gone well up to this point. I turned on the power and it worked! There is clearly a difference in the belt tension as there is some bearing noise at 2000 and 3400rpms. I loosed the bolt on the eccentric and attempted to adjust the eccentric bushing but it will not budge! Has anyone out there had this experience and could you help me with a solution?
Thanks!

Ted
I have to say first that I have not yet built a power pro but I do own one. If you can't move the eccentric it may be that the tension on the motor belt may be keeping the eccentric from moving. My book says to tension the eccentric belt first and then set the tension on the motor belt by adjusting the motor mounts to adjust the motor belt tension. Guess that I may have to do another one to see for myself.
Bill V

I think Bill V. has something there. If you would loosen the motor mounts and free the tension on the motor belt, I think you would be able to rotate the eccentric.

Ya the manuals as well as the design of this part of the Powerpro headstock is pretty piss poor. I fussed with the tension on both mostly adjusting the set screws on the motor mount. tension on both belts is now to the point that each has about 1/4" of deflection when pushing with about 15PSI (as hard as I can push without breaking anything). Final adjustment was made with the eccentric bushing though, just played with it until it quieted down at most RPM's.

superpop wrote:Ya the manuals as well as the design of this part of the Powerpro headstock is pretty piss poor. I fussed with the tension on both mostly adjusting the set screws on the motor mount. tension on both belts is now to the point that each has about 1/4" of deflection when pushing with about 15PSI (as hard as I can push without breaking anything). Final adjustment was made with the eccentric bushing though, just played with it until it quieted down at most RPM's.

That 'piss poor' design is the result of retaining the half century old design of the headstock which was necessary.

superpop wrote:Ya the manuals as well as the design of this part of the Powerpro headstock is pretty piss poor. I fussed with the tension on both mostly adjusting the set screws on the motor mount. tension on both belts is now to the point that each has about 1/4" of deflection when pushing with about 15PSI (as hard as I can push without breaking anything). Final adjustment was made with the eccentric bushing though, just played with it until it quieted down at most RPM's.

I can't confirm or deny as I am neither an owner or a user. Without that experience it is real hard, if not impossible, to make such a value judgement.

Thanks for your input! makes alot of sense! Jim talked about keeping the belt much tighter than on the Mark V! I'll give that a shot!
Thanks,
Ted

bigted wrote:Thanks for your input! makes alot of sense! Jim talked about keeping the belt much tighter than on the Mark V! I'll give that a shot!
Thanks,
Ted

Who's 'Jim"?

I agree with him. Remember the loose couplers????

JPG wrote:

bigted wrote:Thanks for your input! makes alot of sense! Jim talked about keeping the belt much tighter than on the Mark V! I'll give that a shot!
Thanks,
Ted

Who's 'Jim"?

Those owning a PowerPro know Jim to be Jim McCann The chief engineer for Shopsmith and the person who demonstrates (on CD) how to assemble a DIY unit.

Also you can see Jim in one or two Sawdust session videos. He was introduced by Nick.

Please don't ask "Who's Nick?"

When assembling a PowerPro, The procedure is to first pivot the motor from the rear screws (those toward the pulley) After the drive belt is in place, the front end of the motor is swung up and secured by the front screws. This is often a somewhat strenuous swing as the belt gets tighter as the front of the motor is lifted. Once situated it is possible to adjust the position of the motor somewhat.

Explanation: I refer to the front of the motor to be the spindle side.

I should have realized it was JM. Chalk it up to a SR moment!

The 'back' end of the motor is to me the end without a shaft.



Guess it depends upon whether front/rear is relative to the motor or headstock.

Pulley end nails it!