Shopsmith Forums

Belt tension is the sole purpose of the floating sheave and spring etc. The resultant speed change is what the control sheave movement intended. The control sheave lives up to it''s name.

Just a bit of trivia without words. These sketches came from my efforts to understand the sheaves and how they work.
In the sketch on the right, please note what I consider a "hard low speed stop" (when the end of the floating sheave meets the washer). It may not have been designed to be that but it certainly works.

In the sketch on the left, please note what I consider a "hard high speed stop" ( when the vains in the center of the sheaves meet inside of the sheaves. In the real world this meeting of the sheaves just happens to occur when the sheaves measure 1/2" separation at the outside perimeter. They can not/ will not go closer together than that 1/2"

Well that explains the 1 1/4 to 2 3/4range in the chart in another thread.