3 home switches but 4 axes?

I'm finalising the configuration for my new gantry router.

This one has home switches on x, y and z but not on the a-axis.

Can i set up the configuration so that I can actually run the machine?
It now homes x, y, and z fine but I can not run a program because the a-axis does not get homed.

I have not given the a-axis a pin for the home switch when I made the configuration. The configuration has since been altered.

I have tried commenting out the home info in the a-axis area in the .ini file and tried to work in the .hal file but that is more confusing to me...
I have tried a lot of googling but all hits seem to be about no switches at all or switches on every axis.

Any tips?

SvenH wrote:

I'm finalising the configuration for my new gantry router.

This one has home switches on x, y and z but not on the a-axis.

Can i set up the configuration so that I can actually run the machine?
It now homes x, y, and z fine but I can not run a program because the a-axis does not get homed.

I have not given the a-axis a pin for the home switch when I made the configuration. The configuration has since been altered.

I have tried commenting out the home info in the a-axis area in the .ini file and tried to work in the .hal file but that is more confusing to me...
I have tried a lot of googling but all hits seem to be about no switches at all or switches on every axis.

Any tips?

Try HOME_SEARCH_VEL = 0 for that axis

Might want to read up on homing.....
linuxcnc.org/docs/2.4/html/config_ini_homing.html

Thanks for the reply bevins.

I'd actually tried that already but that dis not work.

I found out this morning that I had to add something else too.

I now have:

HOME_USE_INDEX NO
HOME_LATCH_VEL 0
HOME_SEARCH_VEL = 0
HOME_SEQUENCE = 3

The last one being the game changer.

3.12. Immediate Homing

If an axis does not have home switches or does not have a logical home position like a rotary axis and you want that axis to home at the current position when the "Home All" button is pressed in Axis the following ini entries for that axis are needed.

HOME_SEARCH_VEL = 0

HOME_LATCH_VEL = 0

HOME_USE_INDEX = NO

HOME_SEQUENCE = 0

I hope these help
Giorgio