during a routin inspection because of some trouble with alignment on the x axis side I discovered that the freewheeling pulley
whats on the right side has the belt ripple markt in see picture the left wheel.
the reason why this could happen was that the wheel had only one bearing in it, and the plastic what is used a kind of fabric plastic stuff is to soft for this aplication.
I made my own from nylon see right picture and put in two bearings and now it runs super smoth.
if somebody need one I will sell some for $8.00 plus S&H just send me a email to a542002@hotmail.com
greetings
walt