Design help etc required with DIY CNC Router Design / Build

[Jonathan]

Interesting that you consider the pitch error causing crabbing of the gantry to be a significant error. For C7 ballscrews the error is up to 0.05mm per 300mm, and it's not simply cumilative - it is greater over longer lengths but the relationship is not linear so it's not too bad. I would have though 0.05mm is absolutely negligible, you'll get greater errors from other sources.

There's quite a few profile rails on eBay if you hunt around. 15mm rails and bearings will be fine.

If you havn't already look at linearmotionbearings2008 on eBay. His ballscrews seem good, lots of us have bought them and the bearing mounts are cheaper than england...though I'd just make them.
The ballscrews there will be MUCH cheaper than Zapp as you get the end machining for practically nothing and from what I've heard the quality is the same.

Consider using RM1610 ballscrews on X and possibly Y if you want it to go really fast...lower screw inertia and speed with 10mm pitch but half the resolution but that's generally not important.

I can do Nema 23 motor mount, here's some I made earlier:



http://www.mycncuk.com/forums/showth...3-motor-mounts

Altering the design to suit your requirements is no problem...
I can also make the bearing mounts if you send me a drawing / requirements.
(Hmm, looks like you've already noticed them!)

Ballscrews from CNC4YOU are probably the same as Zapp/eBay.