Looking for the cheapest plasma cutter that will work with Mesa THCAD

thats great, please keep posting progress.

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Tommy, thanks hahaha wish I found that...

Ok so did some recon, the 55i or herocut55 (has so many names) reads out the CNC "voltage output pin" 1:1, so I just test cut and had my wife look at the Voltage Meter, roughly 130-145 volts. Now there was a initial start that was a little over the place, reading 600-700-800 and any number in between for a solid half second, then jumped down to the 130-140 range. I tried it on a bunch of amp settings too, all about the same readings.

Next is hooking up Mesa and seeing what voltage I get based on the settings.

I'll let you guys know what I find.

BlueManRising wrote:

Tommy, thanks hahaha wish I found that...

I just test cut and had my wife look at the Voltage Meter, roughly 130-145 volts. Now there was a initial start that was a little over the place, reading 600-700-800 and any number in between for a solid half second.

That is normal. 130-145 is in the range. and th ebig peak on piercing is why you delay before auto sampling torch voltage.

Ok, so just plugged in the Mesa THCad board, got a normal reading 4.517v DC, figured this was normal since the board is calling for 5v, but when I took my reading after torch start on the F/1 jumper setting it read .1v higher, so it was reading only 4.613, so is this right? Or should I be getting something else, haven't tried another F/32 yet, but I'm gonna try after dinner, more to come, anyone else get these readings?

Just changed THCad-300 to f/32 jumper, reading 4.5 mV when torch is on it goes to .2mV and .3mV... Maybe this is why everyone says to use the THCad-10...? Any insight would be appreciated, also maybe I hooked it up backwards, gonna try flipping the input, read on another board there is polarization..

Sorry Calvin for stealing your forum lol ok, just switched to bi-polar mode, reading 2.49v (DC) when tourch is on reading 4.41v (DC) so I'm assuming it's doing something different lol

Ok so after some thinking and moving the torch higher and lower on the material, I'm definitely getting readings close to 1.5v fluctuation, looking at the discussion earlier about the resistors, I can see why they recommend one, it's naturally reading 2.5v standard. It does change going further and closer, so I'm assuming I'm gonna have to decided the readings at the computer and have the controller go up and down based on the reading. I'm finished in the garage tonight, I'll get back to more info once anyone has some insight, but it's been a fun night of testing. (fyi hooking up the wires from the pin 1 and 2 from the 55i, only made the readings go negative, and keeping it in bi-polar mode keeps the numbers normal) gonna do more research and see what I can find.

Have you read the Plasma Primer?

linuxcnc.org/docs/devel/html/plasma/plas...ml#cha:plasma-primer

Check out section 16.

Thank you, good read! Definitely gonna dive into it further but explains way more than I thought. Thanks for the heads up, exactly what I was looking for, it's based on frequency out not voltage, so disregard my voltage comments cause it doesn't mean anything hahaha ok plasma 1, me 0