You should preload the thrust bearing in order to remove slack. Not preload the coupling to remove slack in thrust bearing. Your motor bearings are probably currently taking the load, which is not good.
The thrust bearing is there to transfer load from the screw to the table without any axial slack. As I said previously the coupling should take no part in this. If you are using or "adjusting" the coupling to remove axial slack you are doing something wrong, period.
You need to workout how to preload the thrust bearing correctly.
Phil
Originally Posted by Jay C  Update: I watched the videos done by Quadrant2005 again. He suggested moving the X-axis to the far left so that the left hand side was pushed up against the table. I did this, then use a bar clamp to put a lot of pressure on the shaft clamp as I tightened it. End result 0.0005" backlash. So it was the thrust bearings. Now I'm off to do the same to the Y.
Thanks to those of you that replied, I heard you, but I wasn't getting it.
Jay |