Quote Originally Posted by irving2008 View Post
There's a big thread regarding this idea on CNCZone... seems some have used it successfully and theres a commercial offering based on the idea.
Yes I spotted that. There's two threads, one quite short one about the method I'm using and one huge thread about roller screws which is another story entirely. I may well try making a roller screw if this method doesn't turn out so well.

These photos wore taken yesterday:
Pretty self explanatory - Z-rails are bolted down and really smooth.
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I milled the alu plate square at school, shiny! Never seen such a good finish on aluminium - must be the grade.
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Today I've milled the gantry sides flat at either end and drilled them. Also had to nip a few mm off the end of one of the Z rails. I was a bit worried with it being hardened, but it milled OK taking small cuts. Plenty of smoke...

Also started machining the M16 rod for the Y axis.

I'll post some more photos tonight.

routercnc:
I see what you mean with the bearing jumping now - that is a bit of a worry.