Quote Originally Posted by jimbowley View Post
The setup is SBR20 round supported rails with matching bearings. I don't suppose they are adjustable? or maybe I can buy adjustable repalcements?
Some of the SBR20 bearings have a little grub screw in the bearing housing which will let you take some play out but still not good ideal.

Unfortunately this is what you get with these low spec machines so you either accept and work around or start going down the upgrade route which soon gets you to the point of diminishing returns. Problem is you quickly get to the point where the machine structure becomes the weak link and then you may as well just start a new build as it will be cheaper and probably easier.

Wrecking cutters and material is just part of the learning curve and after a few cutters and sheets you soon start paying more attention to what the machines doing and reacting quicker. To be honest even now after running millions of lines of G-code if I break cutters it's nearly always from clipping something like a screw or clamp on way to home or some fixture offset.
One of the common Gotcha's for new users is when the machine goes homes or Rapid moves to some point on table it doesn't always take the route you expect. This is true when moving two or more axis at same time to a point on table. The motion planner will interpolate the path and move at feed rate so all axis arrive at same time.
So what happens is that while you think it will clear clamps because at the commanded feed rate for that axis it would be no where near the clamp the planner actually slows or speeds up that axis to ensure all axis arrive at same time. This catches many out, esp with Z axis because when retracting the other axis are moving fast because they have a long distance to travel but the Z axis gets slowed right down to ensure they arrive at same time. So the cutter doesn't clear clamps or material like you'd expect..!! . . . . . . This is why you should have Safe Z enabled in Mach3 when homing but in G-code it doesn't apply so can Catch you out if code is produced this way.!