Hi all.

I hope this thread fits under this forum. The machine I'm using isn't really a DIY, I started with a Hermes V3400 engraver and have been hacking it apart to fit my needs, I began by replacing the electronics with an Arduino and a Raspberry Pi. I also changed out the steppers and limit switches to make it run more smoothly. Now I'm looking to find out what else I need to modify to make the machine capable of milling out PCBs with high accuracy.

Ok with that out of the way. I've attached an image of attempt number 1. Disregarding the uneven cut depth (I think the PCB moved after autoleveling), it seems like I'm having wicked backlash/inaccuracy on my Y axis. I am here because I suspect the design of the machine to be the culprit. The X axis screw goes through the center of the gantry. The Y axis, however, drives the gantry through a lead screw in the left side of the machine, in the housing. It relies on a steel rod in the right side of the housing that the gantry floats on, to keep the gantry straight. This seems like it could cause serious accuracy issues. My thought here was to make a whole new bed for the machine and have it driven by the Y axis. What do yall think?

EDIT: I just noticed that the image appears to be rotated 90 degrees counter clockwise. When looking at the image, the Y acid movement is left to right.