sanddrag,
AndyMark has gearstock that they are selling to us (I think). We are machining the holes.
I initially wanted to use the existing pinion and 32 pitch gears but I could not find gears thick enough for reasonable prices. They also did not come pre-hex broached like the AM gears.
About the rpm rating of the igus bushings:
http://www.igus.com/pdf/j.pdf
I looked and it says that their bushings have a surface speed of about 197 fpm. (197*12)/(3/8*pi)=2007 rpms
I picked the ultra low friction bushings from igus. Please correct me if I did my math wrong.
thanks, Vivek