Since I first got this machine I've not been overly happy with the Z Axis. It's main mounting plate had been bent at one time, and both the normal Z movement and also the 'floating Z Axis' used for material sensing only ran on single linear rails, resulting in a bit of side to side wobble and tilt. Don't get me wrong - it works - but it's not overly robust in it's design and there were features that I wanted to incorporate - namely:
A/ Dual parallel rails for the main Z and the floating Z movements
B/ A Magnetic Breakaway Torch Mount
C/ Emergency Stop to be asserted if the Magnetic Breakaway is triggered
Now this is all very well, but I didn't want to strip down the existing Z axis and hence stop me using the machine, while building the new one. So I decided to start from scratch and make a modular Z axis that would be on plugs and sockets and fit existing mounts on the machine.
I procrastinated for a long time, looking at economical ways of getting the linear ways, ball screw and nut, bearings etc until eventually a 'Prototype Z Axis' turned up on eBay. It had been put together but obviously never used, and would need re-making, but it had the linear rails, ball screw and nut, bearings, stepper etc just as I wanted, but for far less than the total of buying the separate items