Originally Posted by
scudzuki
I have an RF45 with servos. It is surprisingly strong for a benchtop machine and I don't feel limited with the work I can do, even compared to a knee mill.
I don't understand why builders are so fond of mounting direct drive steppers on long posts with the potential for bending moment and the motor "winding up" relative to the machine. Given the coarse pitch of ballscrews, a little rotational inaccuracy introduced there could lead to quite a bit of linear positioning error. Why not replace 4 posts with 2 thin rectangular blocks (tons of beam strength = no wind up), mounted top and bottom so as to keep swarf off the coupling and motor output bearing?
Joe