Well finally got started on this. Attached is a photo of the Z axis and a couple of patterns for the router carrier. I still have to make the patterns for the rail carriers and then I'll cast the works out of aluminium.
I'm also going to epoxy pot thread inserts into the MDF for the Router clamp bolts.
My biggest issue so far has been tapping the UHMW with my home made 1/2"-10 ACME thread tap. I made the tap from some ACME threaded rod but it's not the best for this. For one thing. It's the same size as the threaded rod. A standard machine tap is usually a bit larger than the bolts that are threaded into the holes.
Either I have to buy a proper ACME tap or think about creating an oversize ACME tap that takes into consideration the stretch and springback of the plastic. Currently it's just too tight.
More pictures as I go along.
John