Problem with setting up Proma THC

[Plasmagetsmehot]

Hi guys. Im pretty new to the site so if this is in the wrong forum, please forgive me.

I purchased a 5x10 Spidercut CNC system with a Powermax 45 torch. The unit was supposed to come equipped with torch height control, but frankly its been a nightmare. Thats a story for another time.

Long story short, Ive finally received the torch height control as promised, and its a Proma THC Compact. Ive wired the unit up and ensured all wiring is correct, and loaded the new setup file for Mach 3 that was provided by Spidercut. When I put the unit into test mode, the torch will move itself up, but not down. If I reset all the settings in mach 3 (tolerances and whatnot), occasionally it will go down, but not up. It seems both signals are getting sent from the THC control correctly because when I'm in the diagnostic screen of mach 3 I can see it firing both the up and down z axis lights as its supposed to when the THC is active. It just seems that only one of these signals is getting though, and the other is being blocked somehow. Out of all the tests I have put it though, I was able to run a successful test once, all others have failed in the same way. I am hoping someone here has a little bit of experience with a problem like this, as I've been waiting for a solution from Spidercut for 2 weeks already, and I can't seem to figure it out on my own.

[acourtjester]

First question is the Proma you have a 150 or SD. If you have the SD it seems many have not had very good luck getting them to work correctly.
Another thing is do you have the signals connected correctly by this I mean the 3 outputs up/down/arcOK using the signal return connection not the power ground (negative). Many thing this is the same and it is not.

[Plasmagetsmehot]

Thanks for the reply. I have the 150 and I’m pretty sure my wiring is correct. The up/down/arc are certainly correct, and I’m using the ground on my breakout board (next to my up/down/arc terminals) not the power supply neutral. I did originally have it hooked up to the power supply, but I found it didn’t work at all.

[acourtjester]

sometimes the ground on the BOB and signal return are not the same