Shopsmith Forums

Here's my solution to fix a speed control bracket. I read and understood the the forum posts (mostly by Bill Mayo) regarding fixing this quadrant pivot bracket when the arms are bent and the quadrant gear is binding or out of alignment/center.

In the posts the fix generally involves: removing the old tension pin, straightening the arms so the gear is centered on the quadrant, replacing the pin with a #10 bolt using star washers with locktite and a nylon lock nut. The bolt is unthreaded where the quadrant pivots and is greased. One concern is that you do not want the bolt to rotate when the quadrant goes in/out, but instead just pivot on the newly installed greased bolt.

My contribution: I weld a fender washer to the #10 bolt then grind away until I have two tabs protruding. I then bent the tabs so that they fit on either side of one of the arms. This prevents the bolt from rotating and is very vibration resistant. On the fix shown in the pictures, the bolt/axle is free moving and has no unwanted play and the centered quadrant runs freely in/out. The sheave clearance from the arm remains the same as before. Just thought I would share my fix

[ATTACH]13093[/ATTACH]

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Interesting solution! Thanks for sharing.

My own 'fix' uses a jam nut on the far side and the nut pair adjusted to be tight(no slop), but not binding either. The bolt is free to rotate if it 'desires'.

I do not see a need for the bolt(shaft) to be fixed(not rotate).

Thanks to Bill Mayo for the original 'inspiration'!

I believe that the bolt should be held fast for the following reasons:

1. to prevent undue wear to the bores in those bracket ends by the rotation of the bolt - when the holes in the speed control bracket widen, this also allows the quadrant to start to go off-center of the worm gear;

2. it forces the pivot to be only in the quadrant arm itself (were we can pack it with grease) and where there is the more material to have the least effect by wear. I have another pivot bracket that I am going to try and salvage, but first I am going to have to braze the arms with filler and redrill as the two holes are worn open (one hole worn on the inside and the other hole on the outside).

It is not a perfect solution, but I think that the material in the quadrant arm will wear slower than those bracket ends given the forces and the nature of the design.

[quote="gunner66"]I believe that the bolt should be held fast for the following reasons:

1. to prevent undue wear to the bores in those bracket ends by the rotation of the bolt - when the holes in the speed control bracket widen, this also allows the quadrant to start to go off-center of the worm gear]


Good Points! Would a spot of blue locktite 'do the job'?

I read that Bill uses locktite in conjuction with star washers and that it works for him. I believe that he puts either one or two star washers with the locktite on them and tightens the bolt's nut until the washer and locktite bite into the cast metal of the bracket arms. Then he backs off the nut some to get the free quadrant movement. The locktite is then helping to hold the bolt to the star washer and the star washer to the bracket arm. Many ways to skin that cat!