How to setup a 4axis gantry plasma machine using gmoccapy?

Hi, how can I setup a 4axis gantry plasma machine using Gmoccapy?
I have 1 motor runing the X.
2 motors running the Y.
1 motor running the Z.
1 motor driving the rotary.
Linuxcnc v2.7.8 Debian.
Is it possibe to use 2 steppers for a 2stage Z travel?
Thanks in advance.

To start with, you need to upgrade to master to get the gantry features to run the 2 motor axis, if you are running a Mesa ethernet card you will need to install the preemptive kernal befiore installing Master. You may need to upgrade your PC as I found my 32 bit PC could not cope. The mesa THCAD will do the torch height control at a very low price so their hardware is a good option.

Then this recent thread will get you going and includes the config files.

forum.linuxcnc.org/38-general-linuxcnc-q...other-plasma-install

I'm working on a scratch build plasma cutter using a Mesa 7i76e ethernet card and THCAD and am hoping to get a gantry running next weekend but the table is a fair way off.

Your table looks nice.

And this thread shows you how to install the preemptive kernel.

forum.linuxcnc.org/9-installing-linuxcnc...ng-uspace-for-master

Hi rodw.I have installed the preempt kernel but now I'm confused about selecting the right branch from this link:
buildbot.linuxcnc.org/
Shall it be Wheezy (realtime with RTAI)
architectures: i386 under the "master branch development" ?
The table isn't that nice. There are many mistakes you can't see.

Andy has answerd the question. Just to clarify you only need the preemptive realtime kernal if you are running a Mesa ethernet card.
I'm using a Mesa 7i76e. On my old 32 bit PC, the latency shot to over 200,000 with the preemptive kernal so I bought a new 64 bit PC.

This is another recent thread that talks about recent PC hardware that has a couple of suggestions from PCW at Mesa (and others) that I used for guidance when selecting the 64 bit Celeron PC I settled on.
forum.linuxcnc.org/38-general-linuxcnc-q...7-any-good-usff-pc-s

I was unable to get the internal wifi card working and am using a USB wifi dongle using Wheezy but I expected to do that based on what PCW said on the thread above. I think native support for the Wifi card is available in Jessie.

andypught:If your OS is Wheezy and your Relatime is PREEMPT-RT then the version you want is "Wheezy (uspace: realtime with RT-Preempt, and simulation)"
Are you actually using a Mesa Ethernet card, though?


My OS is Wheezy and my realtime kernel is the preempt-rt-as rodw suggested- I have installed linuxcnc-dev-uspace from apt.now the Lcnc version is 2.7.8.The max jitter is too high now and I can't upgrade my PC.
I don't use any mesa cards.

Shall I install the RTAI kernel instead of the preemptive kernel for driving the 4axis gantry X Y Y Z A? Or just keep the current kernel install?

Roll back to the normal Wheezy live CD distro and install master to get the gantry features.

Thanks for paying attention rodw. I'll make a new install and tell you the results.