As in the title, I'm going for something with a small footprint, so have gone with a bridge style design, and mounted the rails underneath the bed with the carriages being fixed to the main frame. With a slightly complex guarding and swarf catchment this might allow the machine to have 1m Y travel and around a 1m footprint, plus I like the way the rails reinforce the bed and keeps the rail contact points in the same place relative to the spindle.

I've attached a layout design I'm thinking to go with, epoxy filled thick wall steel weldment for the non moving parts, to be stress relieved and then machined. Moving parts to be bolted together machined aluminium.

It's HGR-25 rail, X600, Y1000, Z300 travel. Not sure on the ballscrews, probably 2510 C7 with double ball nuts. Likely servo driven, eventually put an ATC on it, but start with the spindle from my preiovus machine to get an idea on the machine's capabilities before choosing the final spindle.

Attachment 454678

I'm keen to get some critique on the design, things I could change to increase rigidity or precision, etc...

cheers