Quote Originally Posted by Andrewg View Post
Not to criticise, but to show I am listening to the grey beards here, and want to copy much you have done:
I understand the frequent suggestion of having the gantry (X) separate and adjustable from the Y linear bearings for squaring up etc. You clearly still have access to your Y linear bearing screws, so adjustment is still available. However would turning the thick Y linear bearing plate into two, with the lower fixed to the bearings and the upper fixed to the gantry and then bolt and pin them when XY aligned to make things more modular and adjustable?
I'm going to answer this Andrew because many won't realize the difference and why it's important, well maybe I should say easier rather than more important.! Ryan might not even realize this yet because it's the first machine he's built.

The Biggest difference is that the 2 plate method doesn't affect the ball screw alignment to adjust the gantry square. However with the single-plate method when you adjust the gantry by loosening the bearing plate you apply a twisting motion on the ball-Nut because the ball-nut mount is attached to the gantry sides which also rotate with the gantry. This puts a bind on the ball-screw so it causes excess wear and lowers the speed.

This then means you have to make adjustments in some other area to bring the ball-screws perpendicular to the gantry sides and parallel to the rails. In a nutshell it's a right pain in the arse.!! . . . The twin plates take all this away.