Re: [CAD_CAM_EDM_DRO] Homing position

Steve Blackmore wrote:

> On Wed, 14 Mar 2012 15:30:38 +0200, you wrote:
>
>
>> Hi All
>>
>> I'm busy converting a conventional lathe to cnc, and wanting to know where
>> people generally place the home position.
>>
>
> Hi Roland - it's not necessary to have a fixed "home" position unless
> you are using servos with a calibration sequence.
>

The real purpose of homing is so there is a known relation to the
machine's travel
limits. If you have pre-set your tools, then all the calibrations are
re-established
when you restart LinuxCNC and re-home. It has NOTHING WHATSOEVER
to do with the type of motors used. Many lathe users have the X offset
for all their
tools pre-set, and so they don't have to mike the diameters over and over
to turn a piece to known diameter. Also, having the Z offsets set makes
it unlikely
you will crash the tool into the chuck jaws by accident.

Once the home position is defined, you can set machine limits from the
machine
home position, and no program will be allowed to exceed those limits.
You can
always set your workpiece coordinate system ("touch off") for the part on
the machine.

Jon