Jonathan,

Thanks for the response, yes it was a typo 1200 is correct. I am not sure on the z travel at the moment I am looking to keep it reasonably short this was the reason for the adjustable bed. What would you consider a reasonable z travel based on machining aluminium?

So I could go as small as 15mm ok that helps I was expecting to need 20mm dont ask me why just thought that would be more the size.

I see you use those bearings on your machine, by saying they will still be worse than the profile rails what exactly am I likely to notice between using the two? (thats not me posing that questions as if im not expecting the profile to be better because I am just wanted to know what key differences in the machined end product)