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Solved: MAX X/Y value of 110 was too high for my small machine.

I was able to do probe calibration by significantly increasing my axis min/max values for X and Y

However, this doesn't solve the issue as I cannot do any regular probing of parts anywhere on my travels without these artificially increased values. Does anyone have any ideas on what offsets might be causing this? My probing was working previously.

I am reclaibrating my probe due to issues I was having in a separate thread, this time using a gauge block. Previously I calibrated it using a 5mm gauge ring and the calibration cycle worked fine. However, every time I try to calibrate on this gauge block I get an error saying I am exceeding either X or Y's negative limit and I can't seem to figure out why this is happening. I am not anywhere close to my axis travel limits. I am attaching pictures of my tool and probe settings. They seem fine to me? I have tried varying the stepoff and nothing changes it. It seems like there is an offset / ini issue that is colliding with the way the probe cal works but I can't figure it out. I currently have my X min limit set to -8 but I tried adjusting it to -16 and I am still getting the same error.  


The picture shows a step off of 20 but I tried reducing it all the way down to 6 incase my min axis values of 16 were somehow messing with it and it did not fix the issue

EDIT I just realized..even if I go back to my old probe_cal value and try to probe a boss, I am getting the axis limit issues as well so it seems like something strange has happened

I was using a mix of ChatGPT as well as YouTube and this forum, ChatGPT works well for more specific but simple issues but as you said, it’s often not 100% correct but for a novice like myself, it gets close enough.

I was using the XYZ congfig as I thought I was the most similar to what I wanted as I will eventually have a third axis. My main issue is I can’t work out how to make it use scara kinematics as I don’t think it’s an option PNCconfig so I think I’ll have to manually edit the files. I am also using the Axis GUI but I’m not sure if I maybe am running into issues with joint vs world mode. My current setup is a 1:2 scale 3d printed model with no homing or anything so I’m really just trying to have a proof of concept. I can make my motors spin. Scara exists in linuxcnc, now I just need to combine them together.

Alright I think that puts us on the right track.

I wasnt really too attached to QtPlasmaC, I just saw the word "plasma" and selected it. Also thought it looked nice.

I did previously create a config with Axis GUI as well but it was more so for testing the motors out, so I will switch back to that and see what I can do.

Thanks! Hopefully my next post is of a finished machine.

OK, then why use QtPlasmaC?
Not helping, here is some help
-Make a normal config for QtPlasmaC
-Do not use input pin for Z home
-Probably edit the ini file and set everything with Home_xxxxxx to 0 <<<this should do immediate homing with no regard to position or switch
-use normally
BUT, this will still try to probe the material and error out...pretty sure something can be done in HAL to wire probe in to probe out, that might just work.
Yeah, still not usable, sorry, typing before thinking, so the simple solution is use Axis GUI.

We just didn't think it was necessary for a tube cutter, and at the start of this whole process we thought we were making it easier on ourselves by omitting it entirely. Also to save some money on all the electronics that go along with an additional axis, as we are working with a tight-ish budget.

Its pretty much only designed to do 1in OD because its for our universities FSAE team, to make the chassis in house, but should be capable of 0.75" - 3" tubing.

There is a Z axis technically but its manually adjustable just to set torch height for different size tubes. Also there is a front chuck of sorts that holds the tube about 2inches from the torch so the material is well supported up to the torch.

Is there any way you can think of to take out the Z-axis related ops? I was trying to figure out how to contact you directly actually because you are the one person I have seen do tube cutters in this forum.

Let me know if you have any advice for us...

Thanks.

Forgot to add, tubes are 76mm and 193mm in diameter, if the scale is not apparent from pictures.

Nkbhvid wrote:

Welectron do not sell mesa products any longer

They do sell Mesa stuff, just type Mesa in the searchbox on their website.

Make 2 configs, one with 4th axis and one without.
Do not ever connect or disconnect motors while machine is powered on.
Does the spindle have an encoder?

unknown wrote:

Try the wheezy ISO from the downloads page,

This is very good advice.
And never mind the 2 core comment, not important in your case.

Pictures of what thing actually cut :

I have to ask, WHY ???
You can not use a plasma without Z axis, except very close to the chuck and with good quality tubes.
I have built 3 by now, all have Z axis and THC, one of them built a huge construction, see here:
forum.linuxcnc.org/show-your-stuff/35306-cnc-plasma-tube-cutter

This is a good thread!

My probing support is in sort of a middle ground, niether fully manual, nor fully automatic. My automatic touchoff probes, and my manual touchoffs, all get logged to a file, courtesy LOGAPPEND/LOG/LOG_CLOSE. For a long time that log wasn't used -- it was just a byproduct of some sample code I'd started with over a decade ago.

But earlier this year I had a need to match the machines coordinate system to my workpiece. ((It was easier than trying to get it clamped down in perfect alignment.) So I wrote some (external) code to pull data from that probe logfile. The code took the last couple of touchoff points, and calculated the rotation angle of a line drawn through those points. And then printed the g-code command necessary to adjust the current coordinate system's rotation, i.e. "G10 L2 P0 R $angle". Later, I realized I could also use the log to find the center point between two probes, so I added that. If the two most recent probes were both done in the same direction, then they were likely probing an edge, and it prints the angle of the edge. If they were done in opposite directions, they were likely probing two edges (inside or out) of something whose center I'm interested in.

And then today, after finding this thread, I enhanced it a little more: It can now also look at the last three probes in the log file and give me the center point of the circle they describe.

All without any data entry, or modifications to my existing probing code. It runs from a button on my desktop (i.e. outside of and beside Axis), and puts up a window with its results. I simply copy the g-code commands it gives to the MDI window.

I'm happy to share what I have, but with caveats: a) it's written in shell, because that's what I like to do, and b), it calls out to a calculator program for the floating point. Almost any other language would have avoided 'b'.

Anyway, thanks for the inspiration, and for the center-finding equations.