I got a little carried away with one of the couplers I'd made for the X axis, and it broke. I managed to jury rig it, but a few jobs I've tried recently have lost X registration. I initially thought it was a backlash issue, or lost steps due to electronic interferance, but the simplest answer is often correct. The broken coupler was most probably slipping...
I needed to make a Z axis coupler, so I thought I'd do a new X at the same time. Here's a quick look at it in action, and also a demo of the new panel.