Quote Originally Posted by Doddy View Post
This is going off-thread, but you have got me thinking. Particularly as I've committed to buy a Chinese pack of rails and screws, delivered in the next week or so (as much to get me motivated to get off my arse and do something).
Well I'm surprised at that.? Thought you'd been around long enough to know better than that.! . . . . Design first then buy later is golden rule.

Quote Originally Posted by Doddy View Post
I'm not a fan of spending a weekend playing with F360, but, and considering this is a fragment of a design (until I get the bits and validate the generic CAD models I've been using are broadly appropriate), is this the sort of thing that you're talking about, and is this a viable starting point for a design.
Yes that's the idea thou wouldn't fasten between those two gantry uprights as it will make setting up difficult with little room for error.
Fasten rails on front, ballscrews on side and put brace between gantry uprights at top. Connect two ballscrews with belt and single motor running along top of brace.
Put rails on front of gantry and ballscrew on top.