Today the roller bearings I orderad arrived. The are of a thin design, 6x12x4 mm. The diameter can't exceed 12 mm because of the narrow space inside the focuser.
http://www.astrofriend.eu/astronomy/...-friction.html
It's relly exiting when you can start assembling the parts, so far I'm really satisfaid over how good this part of the focuser work. Now I can proceed with the push pull rods, I have changed it from M4 to M3 to have a better resolution, about 2.5 my per step (without micro stepping).
/Lars