magno_grail
14-02-2013, 04:19 AM
Hi All, I am building a CNC, just over 300mm cube working volume, stepper drives, 16mm dia. 5mm/rev ball screws . The Z axis has a ball screw at each end of the Y axis. The Y axis forms the bridge. What I have not decided yet is how to gang the Z axis screws together. First choice is to use two steppers directly driving and presume they will stay in sync (weak), second is to use two steppers directly driving with a timing belt in between (strong), third is to use a single central stepper with timing belts to each ball screw (intermediate). The belt would have to be timed upon assembly.
Reading through several other forums, steppers will stay in sync if not overloaded but detecting a sync error without an encoder on both ball screws or homing is difficult. I do not have information on the modulus of elasticity of timing belts so I am not confident a single stepper drive will keep the accuracy of the direct drive. It should be able to keep the ball screws in sync with the two stepper direct drive.
Does anyone have any real data or examples of what works satisfactorily? Thanks.
Reading through several other forums, steppers will stay in sync if not overloaded but detecting a sync error without an encoder on both ball screws or homing is difficult. I do not have information on the modulus of elasticity of timing belts so I am not confident a single stepper drive will keep the accuracy of the direct drive. It should be able to keep the ball screws in sync with the two stepper direct drive.
Does anyone have any real data or examples of what works satisfactorily? Thanks.