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Hi all, its been awhile sorry, not had much time for anything of late and I've just been quietly using my linuxcnc converted bridgeport, but it seems I finally will get to play again.
I decided I have need for a cnc plasma table, so I started to put together a list and get parts.
So far I have:
Usual old PC for control,
Mesa 7i76e for control,
Mesa THC-5,
3x 3Nm closed loop steppers with drivers + psu's, the closed loop function is handled inside the stepper driver so they look like normal open loop steppers to the mesa, I hope they dont get affected by interference...
A 200mm travel z axis
Various limit switches
4 HGR20 rails with trucks and ball screws for x & y
P80 plasma torch suitable for z axis mounting
 

For a table, I have a used very old JCB backhoe chassis that had become damaged in a roll over incident and had to be cut up
I rotated the backhoe chassis and started to cut off extra bits, and put it on heavy casters to roll about already, and am in the process of cleaning it up to mount the rails directly onto it via tapped holes then I'll shim the rail->chassis where needed. 
A chassis for a digger weighing 8t is going to be plenty rigid & I can move it round with the fork truck if needed without worrying about it distorting. I'll mount the control electronics inside the section of the frame at the front that used to form the machine's diesel tank, so it will be good for sheilding + heat dissapation.
 
I'm posting this because I'm a bit hazy on the details how to connect a THC to the plasma unit.
I have a mesa THC-5 ordered, but I'd like to use my Stahlwerk Cut60 because its 380v tri-phase and I have a amp limit to run the table + compressor.  Someone from Stahlwerk told me when I enquired that it was scratch start and I'd need to buy a later model to get HF start, but if you hold the tip near the work you can see a small spark jump before it establishes the plasma and it doesnt need to touch to establish so perhaps something was lost in translation.
I read that the stahlwerk plasma cutters need modification to get some of the signals out for cnc use, my search is failing me for finding more info on what's specifically needed to be done inside this plasma cutter itself, any links?

Also I have only one ballscrew for the table long axis (2m), is moving the gantry axis from one side only going to be ok? I'm a little worried that rapid moves will cause it to go out of square. I dont mind slowing it down a little if that can help eliminate this, I dont care if I have to wait a bit longer for parts.

Looking forward to finally making progress on making something again, and your comments.
 

Now I have wired the button to an Input Pin and the ATC-Valve to an Output.
So I did the configuration now like this in .hal (atc_button is and2 instance):

when I now type "M6 T5" as MDI I can push my button and the ATC valve is acting.
BUT after changing the tool by hand Linuxcnc (gmocapy) still says T1 is inserted.
How is the procedure here to commit the change?

Are the nets  "tool-change-confirmed" and "tool-number " needed somewhere? Or are they just in as a standard for user adjustment / routing?!

By the way: "I have no idea how it´s done usually - cnc newbie"

I've gone through this thread and used the script, made the obvious mistakes of not having irqbalancer installed and having the wrong ip (10.10.10.1 instead of 10.10.10.11) in the script.  I've fixed all that, but I am still having a near immediate error when I start of Unexpected realtime delay on task 0 with period 1000000 followed by a hm2/hm2_7i76e.0: Smart Serial Port 0: Doit not cleared from previous servo thread....

I can move the machine around and run the spindle (modbus issues resolved with group admission change), but after a short while I get an error finishing read and the machine goes in to fault.

The hardware was all working with 2.8, so I don't think there is something that has died as it will all still work in 2.8, it's just this realtime delay issue.  I hate to bug anyone with this as I feel like I just haven't done enough due diligence, but this thread seems to be hitting all the high spots related to latency and I have not managed to resolve it.  Any help would be greatly appreciated.

Kind regards,

Sam

That did the trick Thank-you!

I have a CL57T closed loop stepper driver with alarm output. I have the alarm wired to input 4 and 5 on my 7i96s and it works fine.

Lines 257-267 in HAL:
#  ---estop signals---

net estop-ext     =>  iocontrol.0.emc-enable-in
net estop-out => hm2_7i96s.0.gpio.045.in_not

# --- drive ALM ---
net x-fault => joint.0.amp-fault-in <= hm2_7i96s.0.inm.00.input-05
net z-fault => joint.1.amp-fault-in <= hm2_7i96s.0.inm.00.input-04

net x-fault => joint.0.amp-fault-in halui.joint.0.unhome
net z-fault => joint.1.amp-fault-in halui.joint.1.unhome



My issue is resetting the alarm after it triggers. At the moment, I need to close Lcnc and reopen it to get it to send a new "net x-enable     <= joint.0.amp-enable-out" signal. I attempted to follow This Post but couldn't get it to work. Could I get some direction with this?

polskleforgeron wrote:

 I only have one question though. With the Stahlwerk's HF starts, could it fry the THCAD ? It didn't seem to affect much my multimeter when I tried it.

Also, is there a way to upload directly a video on the forum ? I'd like to show you the machine !

 

The THCAD can handle 500 volt overvoltage which is higher than your plasma cutter will generate so you won't damage it unless you connect >5v to the encoder side (Ask me how I know, 24v is enough to kill the encoder input, but I could use another encoder input on my 7i76e from the plasma firmware)

Upload your video to Youtube and link to it