Z-axis design - help sizing materials please!

[Swarfing]

Well i have just been out in the workshop to finish off the 'Z' of my small desktop machine and screwed it all up because i was interrupted. I cast and machined all the plate i needed, cut it all drilled and milled only to realise all the planes are wrong because i needed to stop and re-adjust my mill head. A point in question relevant here. You can spend a lot of time and effort to make as much as you can but not always effective. I will give up and now buy the appropriate parts. The cost of the time (which is the most precious cost) is what hurts most. The profile will cost more in the end but will make the job easier and quicker to get done. Better to wait a few weeks more and get it right than be in a hurry and see the cost mount up. Just think the time you have in the middle can be used else where?

[phill05]

. The cost of the time (which is the most precious cost) is what hurts most.

Look at the bigger picture, look at what you have learnt this time, next time you should not do it wrong.

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

[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