PROMA THC

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lexmotorsports
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PROMA THC

Post by lexmotorsports »

hey guys,

im running a 4x8 plasma table with MACH3, a gecko g540 board, and a cutmaster a60. i have recently added a homemade floating head and got my Z axis probing figured out. i have my proma thc all wired up correctly, running awesome in test mode and even on cutting. the problem im running into is when i run a gcode file in MACH3, the code will probe the first pierce, then make the cut with the THC active and running (!?!?!) and then after the cut is finished, the Z will try to return to my safety Z clearence (1") but it wont. the Z height goes up about .6", then moves to the next pierce, and tries to continue the code. at this point the THC drives the torch head straight down into the material. im really stuck as ive tried everything that i think i can.

im running the mach3plasma PP in sheetcam and i know it is set to run without a THC. could this be affecting it?

any help would be appreciated.
Jtucker7000
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Re: PROMA THC

Post by Jtucker7000 »

I haven’t ever used Mach 3 so I don’t think I can be of any help. I thought it might be worth making sure you were using the proma 150 right? Not the SD. I’m sure it’s not the issue but I’ve seen other posts where that was the mix up. Unrelated to the THC when you added the floating z did you set the z offset in the post processor? Just a few thoughts until someone smarter than I can weigh in.
PlasmaCam 98z retrofit to Mach4 & Proma THC
Hypertherm Powermax45
Mach 4, CamBam, Inkscape
tcaudle
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Re: PROMA THC

Post by tcaudle »

The only difference in SheetCAm between a THC and NOn-THC POST is the touch off. If you have floating head and have the touch off working then there are a couple of POST parameters that define the touch off frequency the switch offset (mechanical offset)

You need to look at the ACUTAL Z height and the Z DRO readout. If they are way apart you are losing steps while cutting or you do not have your Z properly calibrated as far as Steps per inch. The THC logic in MACH3 has inherent loop delays so you have to de tune the THC Rate % . If its too high you get overshoot and up/down oscillation.

Rapid clearance is in SheetCAM / Options/Job Options.

Follow the Vendors instructions for setting those parameters
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