Another plasma component...

Thanks John,

I managed to find LMDE2 and made a new virtual machine last night, loaded all the dependencies, cloned plasmac and built LinuxCNC.
The colors work fine, I really don't know where to go from here...
Did you guys try the mod to the glade file?

Cheers, Phill.

You guys think a THCAD calibration setting calculator like this would be a useful addition to something like the configurator?
jscalc.io/calc/NTr5QDX6WgMThBVb

[edit]
I hope it works right because I can't figure out how to get back in to edit the stupid thing.. anyway I figure
scale = thcad_model_voltage * frequency_divider * plasma_divider_ratio / (max_voltage_frequency - zero_voltage_frequency)
offset = zero_voltage_frequency / frequency_divider

where max_voltage_frequency and zero_voltage_frequency are from the calibration sticker x1000

AgentWD40 wrote: You guys think a THCAD calibration setting calculator like this would be a useful addition to something like the configurator?
jscalc.io/calc/NTr5QDX6WgMThBVb

[edit]
I hope it works right because I can't figure out how to get back in to edit the stupid thing.. anyway I figure
scale = thcad_model_voltage * frequency_divider * plasma_divider_ratio / (max_voltage_frequency - zero_voltage_frequency)
offset = zero_voltage_frequency / frequency_divider

where max_voltage_frequency and zero_voltage_frequency are from the calibration sticker x1000

Very nice. I must confess I don't use Plasmac's scaling and have stuck with the component I wrote ages ago which does the same thing as your web calculator forum.linuxcnc.org/plasma-laser/32585-scalethcad-component . So I use scaling as 1 and offset as 0 and give plasmac the torch volts already scaled.

I still think that at the end you will need to check it against a known voltage as component tolerances will make a difference.
Although I guess if you are not intending to use the voltage from manufacturers cut charts then it probably doesn't matter too much.

Cheers, Phill.

I certainly wouldn't argue with checking its calibration. I checked my thcad-10 with a 9.5v wall wart and a voltage divider circuit with a potentiometer. I checked it at several different voltages over the 10v range. The calculated voltage using Mesa's calibration frequencies matched my multimeter within 0.1 volts. Speaking just from my gut I think I trust mesa's calibration better than my multimeter. it's a cheapo meter, so I suppose that's the best I can do.

[edit]
Maybe another calculator for the user to plug in a series of their own frequency vs known voltage pairs and do a simple linear regression? let the user decide what they trust. I'm just thinking about convenience for the user. I would offer to do it but I know squat about gui programming in linux... maybe it's a good time to learn though

[edit x2]
Here's my test data. It was closer to +-0.03 volts, not 0.1v.
image missing https://i.imgur.com/JLdmA0I.png

phillc54 wrote: I still think that at the end you will need to check it against a known voltage as component tolerances will make a difference.
Although I guess if you are not intending to use the voltage from manufacturers cut charts then it probably doesn't matter too much.

Cheers, Phill.

But each board is individually calibrated by Mesa so there is no need to do this as most won't have a lab quality power supply at their disposal. Testing with a 9 volt battery is only useful as a simple check to see that you have it set up in the ball park in hal show. Eg frequency count is at 90% of the range.