Ohmic Probe + Material Height Feature Request

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.

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.  

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!

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.

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!

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.

Ok, Sounds Good.
I'll update and give it a try.
Thanks!

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.  

 

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

Yes, I updated the magic comments to include adding material thickness.