Re: [CAD_CAM_EDM_DRO] Homing position

Roland Jollivet wrote:

> Thanks. Thats what I wanted to know.
>
> I will be repeating different parts on different days using jigs, so I want
> to regain my setup as quickly as possible. I can't imagine trying to run a
> cnc machine without home positions.
>

If you have encoders with index pulses, then you can reestablish the
home position
with the accuracy of a single encoder count. If you only have the
switches, then
you need to determine the actual repeatability of them to know what kind of
accuracy you can get from day to day. Many people report sub-thousandth
of an inch repeatability with micro-switch limit switches, but I'm just
a bit
skeptical.

> I am familiar with cnc mills and lathes, but was uncertain about the
> tailstock on a manual machine. cnc lathes usually run the tailstock on a
> separate slide so it's not in the way of Z travel.
>

One trick I would certainly do is to put a microswitch on the carriage
that would cause
an E-stop before the carriage hits it. In fact, my manual lathe has a
big bolt on the
carriage that will hit the tailstock to protect the DRO scale from being
the first thing
to make contact.

Jon