Re: [CAD_CAM_EDM_DRO] Rotary Axis home and/or limit switches

ya_nvr_no wrote:

> I have added a couple of rotary axis's But am having an issue with coming up with a good way to home them. One switch gives me a home position but if I rotate one revolution the switch is made again. I am using CNCpro, it uses a limit switch as the home switch.(would another program handle this better?)
>

EMC2 would ignore the home/limit input when it's not actively homing.
Having a limit switch on a rotary axis that can revolve > 360 degrees
doesn't make much sense, since there is no real limit to travel.

> So for example, an issue on the B& C axis.
> Do I home at somewhere>90 degrees then move the B axis to the vertical position once I know what that angle is? Manual Zero this location.
>

In EMC2, you can define the position of the home switch, it doesn't have
to be zero. There is an independent setting for the position to move to
after homing. The only requirement for home switches is that they
basically split the machine travel into two regions - on one side the
switch is open and on the other side the switch is closed. It's often
easier to place the switches near the end of travel, since you need long
cams and roller levers (or similar setups) if you want the switch near
the center.

> Home the C axis and then rotate it ~180 to find the center of the truncated 360 degree rotation? Manual Zero this location
> And on an A table axis I would be limited to less than 360 degrees.
>

Can the table rotate more than one turn?

> My options are:
> Using a M code or manual toggle switch to disable the homing/limit switches after homing
> or
> Using both home and limit switches, create a logic IC circuit/or PLC that determines conditions.
>

Or use EMC2, which has many many options for setting up homing and limits.

<http://www.linuxcnc.org>
- Steve