Hello Guest it is December 14, 2019, 07:07:31 PM

Author Topic: MACH3 THC not responding to torch up/down inputs  (Read 1110 times)

0 Members and 1 Guest are viewing this topic.

Offline Ow

*
  •  3 3
    • View Profile
MACH3 THC not responding to torch up/down inputs
« on: March 26, 2019, 01:19:25 AM »
I have built a 4ftx8ft plasma table from scratch and everything so far has been working great except the torch height controller function in mach3. All ports/pins are setup correctly and diagnostics screen shows arc okay, torch up and torch down signals working correctly.

I am using the nvem v2 controller and pricecnc thc connected to my hypertherm 1250. Voltage readings are correct and its sending torch up/down/arc okay signals no problem while running some cuts. The Z axis just simply is not moving from torch up/down signals. I have tried emulating signals with keyboard as a test and still no movement. Page up/down jogging z axis works fine and my g code probes the work surface at start of every cut no issues. The arc okay signal does work. with plasma cutter tuned off G code will wait for arc okay before proceeding.

I have tried enable/disable "allow THC UP/DOWN Control even if not in THC Mode" and it makes no changes. If i enable "set OUTPUT5 when in THC" output 5 does toggle on when i switch on the THC enable button. Running in mm and THC max = 20mm minimum = -2mm. THC Speed = 20.

I'm sure its something simple I have missed but don't have much experience with this software yet. Would greatly appreciate any help you may be able to offer. You can see a video of my setup here: https://www.youtube.com/watch?v=RcUxoCZ0VbE



Re: MACH3 THC not responding to torch up/down inputs
« Reply #1 on: March 26, 2019, 01:49:42 AM »
Hi,

Quote
I am using the nvem v2 controller

I wasn't aware that your controller supported THC.....do you have documented evidence that is does so?

Craig
My wife left with my best friend...
     and I miss him!

Offline reuelt

*
  •  439 439
    • View Profile
Re: MACH3 THC not responding to torch up/down inputs
« Reply #2 on: March 26, 2019, 04:36:19 AM »
I have built a 4ftx8ft plasma table from scratch and everything so far has been working great except the torch height controller function in mach3. All ports/pins are setup correctly and diagnostics screen shows arc okay, torch up and torch down signals working correctly.

I am using the nvem v2 controller and pricecnc thc connected to my hypertherm 1250. Voltage readings are correct and its sending torch up/down/arc okay signals no problem while running some cuts. The Z axis just simply is not moving from torch up/down signals. I have tried emulating signals with keyboard as a test and still no movement. Page up/down jogging z axis works fine and my g code probes the work surface at start of every cut no issues. The arc okay signal does work. with plasma cutter tuned off G code will wait for arc okay before proceeding.

I have tried enable/disable "allow THC UP/DOWN Control even if not in THC Mode" and it makes no changes. If i enable "set OUTPUT5 when in THC" output 5 does toggle on when i switch on the THC enable button. Running in mm and THC max = 20mm minimum = -2mm. THC Speed = 20.

I'm sure its something simple I have missed but don't have much experience with this software yet. Would greatly appreciate any help you may be able to offer. You can see a video of my setup here: https://www.youtube.com/watch?v=RcUxoCZ0VbE




A step at a time
1. Is your plug-in "Novusun_NVEM-Novusun-PlugIn-Ver-3.0b" or later?


« Last Edit: March 26, 2019, 04:45:20 AM by reuelt »
"the gift of God is eternal life through Jesus Christ our Lord"

Offline Ow

*
  •  3 3
    • View Profile
Re: MACH3 THC not responding to torch up/down inputs
« Reply #3 on: March 26, 2019, 10:17:51 AM »
Hi,

Quote
I am using the nvem v2 controller

I wasn't aware that your controller supported THC.....do you have documented evidence that is does so?

Craig

I have no documented evidence that my controller supports THC. This is my first cnc machine so I was not aware the controller itself would need to support that. I assumed it would be no issue for the software to simply take a torch up signal and move the z axis just the same as if i was jogging it manually by hand.

I tried setting torch up/down signals to z jogging input but it wont move while running g code. is there a bypass setting that allows me to jog z axis while running a program. I would imagine some guys run with no thc and simply adjust manually while cutting?



A step at a time
1. Is your plug-in "Novusun_NVEM-Novusun-PlugIn-Ver-3.0b" or later?


Yes Plugin ver-3.0b is installed and working correctly. Have also tried reinstalling software and the plugin with no change in results.

Offline reuelt

*
  •  439 439
    • View Profile
Re: MACH3 THC not responding to torch up/down inputs
« Reply #4 on: March 26, 2019, 12:56:10 PM »
most external motion controller fail to support THC

1. Parallel Port Works (MACH3 with win 7 32bits)
2. USB-MC & ETH-MC motion controllers works
https://www.youtube.com/watch?v=xJv*********CplzE
3. ESS still trying to get support for THC

Novem 1.1 was reported on this forum to fail to support THC
Not sure about Novem 2.0 that you have.
« Last Edit: March 26, 2019, 01:02:37 PM by reuelt »
"the gift of God is eternal life through Jesus Christ our Lord"
Re: MACH3 THC not responding to torch up/down inputs
« Reply #5 on: March 26, 2019, 01:46:05 PM »
Hi,

Quote
This is my first cnc machine so I was not aware the controller itself would need to support that.

THC is a realtime function, that is to say that it must respond instantly, or within a few microseconds of a THC_UP or THC_DOWN
signal. This means that the hardware must enact it. If the signal were propagated back to Mach and Machs response propagated
back though the controller the communication delays are too long.

You need to do some research but I'm guessing that your controller does not support THC, many of the Chinese made controllers
do not.

Most of the US and European made controllers do support THC.

reuelt is wrong, the Ethernet SmoothStepper DOES support THC in Mach3, and has done for some years. The USB SmoothStepper
by the same company does not support THC, the USB communications  are deemed being too subject to EMI to be useful
for a plasma table. He is confusing THC support in Mach4.....it is being Beta tested now.

Quote
I tried setting torch up/down signals to z jogging input but it wont move while running g code.

That is correct, once the Gcode interpreter has control of the motion controller then you can't jog at the same time.
If you like, that is the challenge of THC support.

Your choices are:
1) Forgo THC altogether
2) Use Machs parallel port (Windows 7 32 bit or earlier required)
3) Buy an external motion controller like a SmoothStepper that does support THC
4) Use Mach4??

I have suggested Mach4 because they have released ( as development version only just yet) a script based THC solution.
At the start of this post I commented that THC is a realtime function, and the communication delays preclude a software
solution. Mach4's communication delay are much less than Mach3 and so NFS have written a script  (software) solution.
Provided the movement required is not too rapid then it will work. If your machine cuts very quickly and demands
rapid THC movements then genuine realtime THC support is required.

Craig
My wife left with my best friend...
     and I miss him!

Offline Ow

*
  •  3 3
    • View Profile
Re: MACH3 THC not responding to torch up/down inputs
« Reply #6 on: March 26, 2019, 03:29:16 PM »
Thanks alot for all the information! I always just assumed the thc function was script based like your describing mach4 to use. I keep forgetting this software is almost the same age as me and designed around much slower systems.

I have downloaded mach4 and looks like I wont be able to make this nvem v2 work with it so I will be upgrading to something better. Maybe use this nvem for some other future project.

It sounds like the Ethernet SmoothStepper would be the best option for me. Looks like they support mach4 too which would be a nice upgrade.

I will keep messing with it while I wait for new controller and update this thread if I find another solution.
Re: MACH3 THC not responding to torch up/down inputs
« Reply #7 on: March 26, 2019, 03:43:19 PM »
Hi,

Quote
I keep forgetting this software is almost the same age as me and designed around much slower systems.

Really its not so much that the PC is slow but it is the buffered communication protocol that determines 'around
the loop delays' of tens of milliseconds for Mach3.  Those delays preclude the effective use of a software closed
loop control.

Mach4 is faster, depending on the controller, most being Ethernet connected, about ten times faster, and therefore
suitable for a (non demanding) closed loop THC system.

There are no Chinese made boards (despite their protestations to the contrary) that are Mach4 ready, and only about
five or six US or European manufactured boards that are ready to go. Of those only the Hicon is THC ready although
the ESS is days away from adding realtime THC to its list of supported features.

Even if you wish to go to Mach4 just in order to get the script version of THC you will still require an external controller.
The ESS is a sensible choice for you as it (will eventually) support realtime THC, thus you have a choice.

Craig
My wife left with my best friend...
     and I miss him!