Woo hoo!, today I had what I'm categorising as my first full on successful run though a whole sign engrave program. There are caveats, the backlash, particularly in the x axis is evident in a few places, however it was consistent and over 3 passes (1mm step down per pass) I got very consistent results.
After the first successful run, I upped the feed rate about 25% and upped the seek rate about 50% and ran again. I got another very consistent result. 3 full passes and very little deviation from the path each time. So I am very happy.
Here is the customary timelapse, you can tell that the second pass is running faster.
I did try to cut a piece for an anti-backlash block, however that failed when the bit slipped a little then bit into the wood and just pulled in. However it was also clear at that point that the model I downloaded wasn't really scaled quite right for my needs. So the plan for this week is to design my own, and maybe hand craft the gcode a little to work around the backlash issue.
I've also been designing an openSCAD design for one of the rubber band guns I made a while ago, I think it would be cool to cnc out the parts for a second.