A new hope: Epoxy granite and steel.

[jarjar]

The Z looks complex. I assume you have a complete machine shop to build it. Ideally it should be as wide as the gantry carriage.

I would go fixed gantry for the relatively small working area you planned.

Maybe also consider simplifying the shape of the columns, but in the end you'll be the one to build the molds :)

[hardenum]

The Z looks complex. I assume you have a complete machine shop to build it. Ideally it should be as wide as the gantry carriage.

I would go fixed gantry for the relatively small working area you planned.

Maybe also consider simplifying the shape of the columns, but in the end you'll be the one to build the molds :)

I do not, all I have is a hand drill and a dremel, I'm outsourcing it. The sheet metal cutting and welding. It's not more complex then a straight or a C plate. It's just a square steel tubing in the end. I've actually received a quote for the whole piece from the local shop EUR600 total for the thing.

Besides the Z, nothing is final yet. I'd go with a fixed gantry but I haven't got a clue yet as to how I'd deal with the bed. What I mean by that is I want to be able to mount the 640x320 work piece vertically. With a moving bed, I don't have any ideas how to do that though.

[jarjar]

I do not, all I have is a hand drill and a dremel, I'm outsourcing it. The sheet metal cutting and welding. It's not more complex then a straight or a C plate. It's just a square steel tubing in the end. I've actually received a quote for the whole piece from the local shop EUR600 total for the thing.

What about the pretty much mandatory stress-relieving after welding, the precision milling/grinding for the rails, boring for the spindle body, milling for the spindle flange?

[hardenum]

What about the pretty much mandatory stress-relieving after welding, the precision milling/grinding for the rails

stress-relieving is in the quote. No under-rail machining, epoxy leveling them. If I were to have them machine all the required surfaces on it, might as well find a different hobby. Machining prices in germany are off the charts. One time I wanted to bring my 300x200mm aluminum heatsink for a shop to mill 3x 10mm wide 200mm long cannals on the underside for heat pipes, the quote was EUR2000.

boring for the spindle body, milling for the spindle flange?

You mean the cartridge? I'm not doing it from scratch. I'll be (or rather the shop will be) making a different drawbar for one of these https://ae01.alicdn.com/kf/H06429625...c015c524f3.jpg, and slightly modifying the spinning part on their lathe. You are right though, that is not a part of the quote above.