Z-Plunge advice sought...

[Wal]

Hello all,

I'm in the latter stages of my mini-mill design - just looking to finalise the placement of the Z-Axis on the frame.

Have a look at the attached diagram - you can see that my Z has a plunge of 150mm. In the diagram the plunge bottoms out with the spindle touching the machine bed - probably not something that you'd want to see in the real world - so my question is: how much clearance would you recommend leaving between the spindle at it's bottom-most position and the machine bed? I know that this is one of those questions where the answer is influenced by further factors (machine use etc.) but is there a good clearance distance to start with?



Thanks for any advice you can offer!

Wal.