smreish
Wed 16 November 2011, 19:11
Recently a thread discussed using rubber bands, zip ties or what ever else to tension the MechMate drive motors to the rack. This had me think that "what if it's too tight" ? What if the motors have too much direct tooth pressure and not enough movement within the engagement to "find a comfortable mesh".
I visited a machine locally that had begun to show signs of chatter and restriction of movement on the x/y change during curve and circle cutting. This is usually the sign of the everything beginning to loosen up. A grub screw, a bearing hold-down, a motor pivot shaft - something. This machine was what appeared perfect.
What I found was the machine, over time, actually tightened up some, and was restricting the gentle (built in the design) anti-backlash performance of the machine. What we found was that the too tight spring, the slightly tight adjustment bolt/nut on the swing plate and the slightly to snug motor pivot point caused the machine to make noise, shutter on transition and expose inaccuracies.
Moral of the story....sometimes loose is good.
I visited a machine locally that had begun to show signs of chatter and restriction of movement on the x/y change during curve and circle cutting. This is usually the sign of the everything beginning to loosen up. A grub screw, a bearing hold-down, a motor pivot shaft - something. This machine was what appeared perfect.
What I found was the machine, over time, actually tightened up some, and was restricting the gentle (built in the design) anti-backlash performance of the machine. What we found was that the too tight spring, the slightly tight adjustment bolt/nut on the swing plate and the slightly to snug motor pivot point caused the machine to make noise, shutter on transition and expose inaccuracies.
Moral of the story....sometimes loose is good.