1. User Interfaces
  3. Plasmac
  5. Ohmic Probe + Material Height Feature Request

Ohmic Probe + Material Height Feature Request

  • EW_CNC
  • EW_CNC's Avatar Topic Author
  • Offline
  • Premium Member
  • Premium Member
More
11 Apr 2025 16:08 #326077 by EW_CNC
Ohmic Probe + Material Height Feature Request was created by EW_CNC
I would like to suggest a feature to fine tune ohmic probing.
Problem: When I set the probe height to an optimal setting for a thin steel setting, it will be too low for thicker steel, and set for thick steel it has excess travel.
My solution would be to add the material thickness to the plasmac.probe-start-height.
Keep the probe height setting function the same, but add a new setting into each material entry for material thickness.
To try to see if it would work, I used the puddle jump delay setting and used the sum2 function to add that number to the probe height. It seemed to work as expected.
With material thickness added the probe height should be more consistent with the top of the material.

This is the code I added to the custom_postgui.hal file.
unlinkp plasmac.probe-start-height
unlinkp qtplasmac.probe_start_height-f
unlinkp qtplasmac.puddle_jump_delay-f

net material-thick          sum2.0.in0 <= qtplasmac.puddle_jump_delay-f
net probe-start-height      sum2.0.in1 <= qtplasmac.probe_start_height-f
net probe-material-height   sum2.0.out => plasmac.probe-start-height

Please Log in or Create an account to join the conversation.

More
12 Apr 2025 01:37 #326136 by snowgoer540
Replied by snowgoer540 on topic Ohmic Probe + Material Height Feature Request
I’ve had a similar thought in the past, with regard to speeding things up.  I was thinking of automatically compensating the probe height based on material thickness, as you said, added to the material fields.

I like the idea, and since someone has officially asked for it, I’ll start looking into making it happen.

Give me some time, I’ll let you know when it’s ready for you to try out.  It will be added to 2.10 by the way.  
The following user(s) said Thank You: EW_CNC

Please Log in or Create an account to join the conversation.

  • EW_CNC
  • EW_CNC's Avatar Topic Author
  • Offline
  • Premium Member
  • Premium Member
More
12 Apr 2025 02:32 #326138 by EW_CNC
Replied by EW_CNC on topic Ohmic Probe + Material Height Feature Request
I just updated my plasma to 2.10 so that will be fine.
Take your time, so far I'm liking the improvements you contributed to QtPlasmaC. It's been awhile since I had last updated, so now I'm trying to catch up!
The following user(s) said Thank You: snowgoer540

Please Log in or Create an account to join the conversation.

  • EW_CNC
  • EW_CNC's Avatar Topic Author
  • Offline
  • Premium Member
  • Premium Member
More
25 Nov 2025 02:46 #339181 by EW_CNC
Replied by EW_CNC on topic Ohmic Probe + Material Height Feature Request
I have added the Material Thickness parameter option for Ohmic Probe with Material Height.

The updated files are in the attached qtvcp folder. It needs to be placed into your working machine config directory.
Also the attached custom_postgui.hal must also be in your machine config folder.

The qtplasmac-imperial_material.cfg file has the material thickness added, it has the settings for a Hypertherm Powermax 85.

Snowgoer, I'm not sure if the custom_postgui file is the proper place to do the hal pin linking. If you have time to review the changes and add it to the source code, I would appreciate it. Otherwise I can try to figure out git and do a pull request.



File Attachment:

File Name: qtvcp.tar.gz
File Size:780 KB

File Attachment:

File Name: custom_postgui.hal
File Size:0 KB

File Attachment:

File Name: qtplasmac-...rial.txt
File Size:24 KB
Attachments:
The following user(s) said Thank You: tommylight

Please Log in or Create an account to join the conversation.

More
25 Nov 2025 12:30 #339206 by snowgoer540
Replied by snowgoer540 on topic Ohmic Probe + Material Height Feature Request
In fairness, you did say "take your time" :-).  I honestly didn't realize it has been since April that we talked about this.

I have a ~75% diff created.  I will try to make time to see this to completion in the coming days.  I'll take a look at what you've provided and no doubt merge it with what I've got and it'll be a nice little collaboration. 

Thank you for providing what you did, I will let you know when I've committed everything!
The following user(s) said Thank You: tommylight, EW_CNC

Please Log in or Create an account to join the conversation.

More
23 Dec 2025 01:35 #340408 by snowgoer540
Replied by snowgoer540 on topic Ohmic Probe + Material Height Feature Request
I finally got this to the finish line.  Thank you for what you provided, but from a qtplasmac standpoint all development on 2.9 has ceased.  I have pushed this update, and book ended it with some bug fixes, but to the master branch only (2.10).

github.com/LinuxCNC/linuxcnc/commit/4e26...712bc80a993377610a37

Your way seems like it would work though. 

All that said, I would encourage you to move to 2.10 and test these features if your production risks allow it.  There have been a fairy amount of bug fixes/feature updates since 2.9.
The following user(s) said Thank You: EW_CNC, NWE

Please Log in or Create an account to join the conversation.

  • EW_CNC
  • EW_CNC's Avatar Topic Author
  • Offline
  • Premium Member
  • Premium Member
More
23 Dec 2025 02:57 #340409 by EW_CNC
Replied by EW_CNC on topic Ohmic Probe + Material Height Feature Request
Ok, Sounds Good.
I'll update and give it a try.
Thanks!
The following user(s) said Thank You: snowgoer540, NWE

Please Log in or Create an account to join the conversation.

More
24 Dec 2025 16:00 #340465 by snowgoer540
Replied by snowgoer540 on topic Ohmic Probe + Material Height Feature Request
I should probably mention how it's set up.  You will have a spinbox for Slat Height in the Probing section, and a spinbox for Thickness in the Material section of the Parameters tab.  If you set BOTH the Slat Height AND the Material Thickness, then the probe start height will change based on the material thickness. 

If either Slat Height OR Material Thickness are 0, then it will default to Probe Height.  A high level recommendation I have (I have not tested this in practice, yet) would be to set Probe Height to 0.  When Probe Height is 0, the probe movement will begin at probe speed from the current Z position.  In most, if not all, cases while running a program, this would start a 5mm (0.197") below Z maximum height, as the g-code filter automagically adds these moves by default.  That means that if you forgot to set a material thickness, your probe would start from the highest point possible, and it would probably be obvious that you need to fix it, and it would be the "safest" option.  

 
The following user(s) said Thank You: EW_CNC

Please Log in or Create an account to join the conversation.

More
24 Dec 2025 16:45 #340467 by MTTI
Replied by MTTI on topic Ohmic Probe + Material Height Feature Request
Hello snowgoer540,

I had a quick question: would it be possible to also set or override the Material Thickness using magic comments in the G-code?

The idea would be to pass the material thickness directly from the CAM/post-processor, to avoid manual input and reduce the risk of forgetting to set it in the UI. This could be especially useful when running multiple materials with different thicknesses in sequence.

Regards

Please Log in or Create an account to join the conversation.

More
25 Dec 2025 04:03 #340481 by snowgoer540
Replied by snowgoer540 on topic Ohmic Probe + Material Height Feature Request
Yes, I updated the magic comments to include adding material thickness.

Please Log in or Create an account to join the conversation.

Moderators: snowgoer540
  1. User Interfaces
  3. Plasmac
  5. Ohmic Probe + Material Height Feature Request
Time to create page: 0.082 seconds
Powered by Kunena Forum