DIY CNC machine for steel?

[Neale]

Interesting, but personally I wouldn't touch them for a mill conversion. I'm using something similar (although home-built) on my current CNC router. They've been working reasonably well, but only because the router is an MDF structure that can't manage anything like reasonable speeds or cuts. For a mill - no way! There's a reason why people say "use ballscrews"..

[Davek0974]

To get ballscrews, look to China if you are price conscious, guy called BST Automation on Aliexpress site, will have all you need, is very helpful and prices, well, I just bought all the motion - linear rails, carriages, ballscrews, nuts, brackets etc for my mini CNC build for the price of a couple of screws alone from a UK supplier.

I usually shop UK but I could not have done this build if I had.