I've had a K2 15"x25" for about a decade and due to life circumstances I haven't really used it for the last 5 or so years. Circumstances have changed and I've moved to a place where I have a huge double garage and only one vehicle that barely takes up 16' of the 24' length. I've got room for all my woodworking tools plus the K2 PLUS a bigger wood router table! I'm going to dedicate the 15x25 to electronics if I get this 48x48 built.
One thing that got me excited was finding out phidgets carries all sorts of linear motion supplies now and for not much money. I realize this means its probably not what you'd call top of the line quality but I'm a hobbyist and I still haven't managed to wear out anything on the K2 which uses plastic anti-backlash nuts so I'll probably be dead before anything wears out. I'm also not worried about 0.000001mm accuracy - this will be wood and the difference in temperature between the shop and where the piece ends up will result in more inaccuracy than the CNC machine anyway. Plus just about everything I make will be decorative and not in need of high tolerances.
Anyway, what I'm thinking of using is the 25mm x 1400mm ballscrew in the X and Y (useful travel 1252mm or 49.29") https://www.phidgets.com/?tier=3&cat...=34&prodid=672. Haven't even started thinking about single or double Y ballscrews or single motor w/belts/chains or double motor. Do you think this will be heavy enough to avoid whipping yet not so heavy as to be overkill? They do have smaller ones but the price difference isn't that great so I'd rather go big if it doesn't cause other problems.
For bearings and rails I was looking at 25mm supported round rail and open bearings (https://www.phidgets.com/?tier=3&cat...=34&prodid=652 and https://www.phidgets.com/?tier=3&cat...=34&prodid=681) Of course these rails will have to be longer than the ballscrew travel to accommodate the X Gantry width and Y carriage but I'll figure out that detail later. I'll probably get extra long and cut where necessary.
For some of the framing I'd use their PG40x80 T-Slot extrusions (roughly 1.5" x 3") with connectors to build taller or thicker. I'm thinking perhaps the Y plate and X wings may have to be machined from aluminium for stiffness but I'm not adverse to trying the T-Slot if there's a decent chance it'll be strong enough.
Like the title says, I'm just spit-balling at the moment and wondering if you folks think this plan is good or foolhardy?
Edit: I mak speel gud!