Z-axis design - help sizing materials please!

[Jonathan]

On another note I built a z axis a few weeks ago, after reading through all the different information on here and other forums I decided on 20mm x 340mm profiled rails fixed to back plate and carriages moving, just got it all powered up and I don't see any deflection/movement whatsoever, I am getting a perfect cut finish and this is on alley.
The rails and carriages were bought off e-bay as used and have no problems with them.
Phill

Ok you've convinced me that this is the way to go - thanks! I'll buy them asap. Have you got a picture of your Z axis as I'd be interested to see?

2e0poz:
I had a similar experience. I started out by trying to make the Z axis with plywood and the bearings on aluminium angle method. Oops. It was horribly bendy...still as phil05 says, I've learnt not to try that again and I've not really lost much. One good point is the backlash was <0.005mm!

[phill05]

Just landed on e-bay 150483471899

Phill

[Jonathan]

Those are tempting. I bet they will go up in price a lot though!
Would only one carriage per rail be sufficient for my application?

[phill05]

As I said I have no problems with the single carriage per rail solid as a rock. I bought two sets of 340mm two rails & four carriages for just over £100 plus postage have a look here http://www.mycncuk.com/forums/showth...?2069-Re-build, will get some more images soon of it all together cutting metal.

Phill