How I would do it:

Use a trapezoidal screw and a delrin nut.

Allow the nut to float axially in its housing, with a microswitch to
detect when it has moved.

Normally the head hangs on the nut. When the head touches then the nut
slides down in its housing, operating the microswitch. (Use the probe
G-code)
back off to the required height + the known actuation distance and
start the arc.

I think I would use a leaf-spring suspension to supply the required
angular constraint on the nut.

-- 
atp
If you can't fix it, you don't own it.
http://www.ifixit.com/Manifesto

------------------------------------------------------------------------------
Everyone hates slow websites. So do we.
Make your web apps faster with AppDynamics
Download AppDynamics Lite for free today:
http://p.sf.net/sfu/appdyn_d2d_nov
_______________________________________________
Emc-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/emc-users

Reply via email to