Quote Originally Posted by routercnck View Post
The Z axis actually moved the whole gantry beam up and down, which although I've seen it done is unusual on DIY machines.
If you watch closely the area above the tool whilst it's skimming the top and inside surfaces you can see that there is a Z with 1m to 2m travel which seems to be what they use for this job rather than movement of the whole gantry.

- Nick