Shopsmith Forums

Again a great informative answer, thank you. Loosened the belt and yes can adjust the eccentric. Have it at about 6:35 position. Have tightened the drive belt, as you mentioned, a very subjective adjustment-- what is your experience with how tight is tight for this drive belt?

c2h6o wrote:Again a great informative answer, thank you. Loosened the belt and yes can adjust the eccentric. Have it at about 6:35 position. Have tightened the drive belt, as you mentioned, a very subjective adjustment-- what is your experience with how tight is tight for this drive belt?

6:35 OR 7:00??

c2h6o wrote:Again a great informative answer, thank you. Loosened the belt and yes can adjust the eccentric. Have it at about 6:35 position. Have tightened the drive belt, as you mentioned, a very subjective adjustment-- what is your experience with how tight is tight for this drive belt?

I went the DIY PowerPro route. Instructions in the video suggested that the belts be very tight during assembly. The upper belt is the same as on a conventional headstock so it seems reasonable to me to apply the same standard. So if you push hard on the upper belt and it moves more than 1/8" it is too loose. In that case I would tighten the lower belt first, balance the belts using the eccentric, then check the upper again. My two cents.

- David

I did the DIY PP upgrade as well, a few years back. Have watched the video multiple times-just reviewed again. For the life of me I don't see how to tighten the lower belt. I understand tightening the drive belt, using the eccentric to balance the two belts, but tightening the lower belt independently after it has been installed, I don't know how to do this--I see no mention of this in the video. Again, appreciate your help here. I have an ever so little bearing rattle that I am trying to address.

The lower belt is adjusted via the motor mounts. The motor can be raised or lowered with the adjustments on the mount thereby increasing or decreasing the belt tension. Remove the Motor Pan to access the mounts. At least that is what I remember from when I did the DIY install a few years ago.

Thank you so very much

Russ is right. This is on pages E-3 and E-4 if you have the manual. You slightly loosen a couple of button head mounting screws on each side, then there are two setscrews at the pulley end to adjust belt tension. "No more than 1/2 turn increments." Then there are two 'Belt Alignment' button head screws at the opposite end, use these to adjust so that a straight edge on the face of the motor pulley is aligned with the center of the Poly-V pulley on the Idler. Then lock both adjustments down with the mounting button head screws.

The adjustment screws can drift due to vibration, so I would make sure they are in contact before loosening the mounting screws. And adjust them in pairs so the motor remains straight. IIRC, the belt alignment screws adjust the same number of turns but in the opposite direction of the tension setscrews.

Critiquing the manual - The sequence is balance then motor belt tension. It does not say to go back and balance after tensioning the motor belt. I'm pretty sure that is necessary.

- David

Thank you so very much