Shopsmith Forums

Why do you start the poly belt on the third groove?

IMHO...to properly align with the idler pulley. Although I have seen posts where it is equally spaced. I'm assuming it all depends on the idler shaft and the power shaft alignment. Hopefully the "pro's" here will enlighten us!

The Mark 5/V idler pulley has 9 grooves(the belt has 9 ribs), and the drive sleeve pulley has 13 grooves. By placing the belt into the third groove, the belt is centered on the drive sleeve pulley. Now that assumes the positioning of the idler shaft pulley.

However if you are working on a Mark VII, the belt has 13 ribs and both pulleys have 13 grooves.

If you are installing a Mark 5/V belt on a Mark VII, then the third groove in both pulleys should align correctly.

FWIW I recommend the 13 rib poly-v belt from Bandsaw Tire Warehouse. Expensive fer sure but more gooder!!!

I am assuming you are working on a Mark VII because of the questions you have been asking.

yes and thank you for good job on switch works great