Controlling Machine Power With G-code?

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Controlling Machine Power With G-code?

Post by MDGCompany »

Hello to all,
I am new to the CNC Plasma and I am in the process of retrofitting a table with the Myplasm controller. I am replacing the older Torchmate software.
I was curious, do you set the amps for each cut based on material or do you just set your machine to the maximum and adjust speed for the material for the best cut quality?

I have a cnc laser that I have been using for quite a while and with it I change the power or the speed, depending on process, for the material.
Usually if I am cutting I program the machine for a MAX power and Speed and adjust manually at the machine if necessary.
So I am asking if I set my machine (Thermal Dynamics Cutmaster 80XL) to max amps and adjust my machine speed should I get a good quality cut on thinner material?

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Re: Controlling Machine Power With G-code?

Post by weldguy »

Setting the machine to max amps and adjusting speed will get it done fast if your cnc table can handle the high speeds with thinner materials but certainly not the best approach.
Rule of thumb I use is to select the lowest amperage nozzle i can use to cut a given material thickness, this will provide the thinnest kerf width and most defined cut.
Set the amps and speed up appropriately using your cut speed chart for the selected nozzle, do some straight line test cuts to get things tweaked perfectly, then make your final cuts.
Thinner material in particular you want a smaller nozzle for narrow kerf.
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Re: Controlling Machine Power With G-code?

Post by bLouChipBlacksmith »

Adding to @weldguy suggestions, here's a pattern I like to use when dialing in amps and feedrate.
I use Sheetcam builtin shapes to draw it, and a -1.5mm overcut in the jet operation to leave the hanging tab, just enough to hold it from dropping. I use needle nose pliers to simply fatigue the tab to break off the part without needing to disturb the material location. This way I can examine the 'save' part cut edges. Examine, make adjustments, cut another one; repeat until happy with settings. Cutting more is easy withe the same file, just index XY zero on the table to a new adjacent position. Be sure to turn off THC on these tests; I also use this test to discover the THC set voltage once settings are stabilized.
Screenshot 2024-04-27 144127.jpg

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