Trouble with dual motor gantry setup

This is a new install on a cnc with dual motors on a gantry on X, and single on Y and Z.
I have followed forum.linuxcnc.org/49-basic-configuratio...s-on-one-axis-gantry
to try to setup a gantry system with dual motors on the X, but cannot get the jogging to work as expected.

Am running the silverdragon frontend and when I try to jog X one motor jogs. When I try to jog Y the other X motor jogs. Z jogs Y and cannot jog Z at all. It seems straight forward that it is getting out of sync, but cannot see what I should change.

If I change to gmoccapy I changes so that the XY and Z jog Ok, but the second X doesn't.
Do I have to do something in the frontend setup to hook this up.

I have confirmed with the stepconf wizard that all steppers work on the pins indicated.

Don't know if it is relevant, but when I try to jog the Z and Y motor moves the display show the Y-Axis moving

BTW very new to linuxcnc (not an excuse, just a mitigating factor)

That is an old thread and a lot has happened.
Refer to the real docs..
linuxcnc.org/docs/2.8/html/config/ini-homing.html

Assuming you have V 2.8 or higher, you need to change the HOME_SEQUENCE for your two joint X axes to be -1. This tells the system to treat them as one.

If < 2.8 you need to upgrade.

Thanks for that, have 2.8. will try it tomorrow.

Hi Peter,
take a look at chapter 6.10. HOME_SEQUENCE on.
linuxcnc.org/docs/2.8/html/config/ini-homing.html
Your home sequence doesn't seem right. Gantry axes have one - in front of it. That is probably the reason why your 2 X-axis does not move. It is not homed.
If you want all homing with one button, the sequence is also set.
HOME_SEQUENCE = 1 # first axis mostly Z;
HOME_SEQUENCE = 2 # X or Y.... and so on

In the case of a gantry axis, write -1 or -2 in both axes.

chris@cnc wrote: Hi Peter,
take a look at chapter 6.10. HOME_SEQUENCE on.
linuxcnc.org/docs/2.8/html/config/ini-homing.html
Your home sequence doesn't seem right. Gantry axes have one - in front of it. That is probably the reason why your 2 X-axis does not move. It is not homed.
If you want all homing with one button, the sequence is also set.
HOME_SEQUENCE = 1 # first axis mostly Z;
HOME_SEQUENCE = 2 # X or Y.... and so on

In the case of a gantry axis, write -1 or -2 in both axes.

HOME_SEQUENCE = 1 # first axis mostly Z; should be HOME_SEQUENCE = 0 # first axis mostly Z;

Thanks for the help, the led me in the right direction.

Funnily enough I was leaving the limit switches until I was sure that I had all the motor setup and direction sorted. This is a bit of a beast of a machine so I am a little bit tentative on doing things like pressing the home all

After trying to setup the limits I realised that we only have a single sensor on the X with the dual drives so treating it as a XXYZ probably has no benefit (the 2nd sensor got destroyed in a previous life). I have now set it up as recommended in forum.linuxcnc.org/38-general-linuxcnc-q...-on-one-joint#142088 and I seem to have more success.

I am sure this won't be the last question, but thanks for the help.
I have currently switched to gmoccapy mainly for the ability to override limits. If you go past limits on this machine it is hard to get it back (the gantry does not easily freewheel and weighs a ton)

I did not see a config specifically for what I am doing as this has a single sensor on each axis that is always on when inside limits, but was able to work it out