plasma kicking out after start

[bittauto]

Hello I'm new to this cnc plasma world. I just got done building my own simple 2 axis rotary tube plasma machine
my problem is that when the plasma lights it will stop in a sec the gfi outlet pops and the machine stops. so I figured I had a bad ground to the machine itself, turns out I did. So I fix the ground in the cord and now the gfi doesn't pop but now the arc will stop and the machine losses its path. So
I drove a grounding rod in the ground and ran a stranded copper wire #6 10ft to the machine and it still does the same thing.
If I don't let the cutter arc the machine runs it path perfect.
Is this because I'm running a cheap plasma cutter (Amico pilot arc apc-50hf)
I'm using mach3 with a usb novuson bob.
I'm sure I will probably get beat up for being cheap but I'm ready for it lol, if this is the problem I'll buy a different one Everlast or Hypertherm
if anyone could give me some advice or something to try that would be greatly appreciated.
thanks

[weldguy]

Sounds like you are seeing high frequency interference and if your plasma cutter is not designed with an arc starting system to eliminate this HF noise then yes your plasma cutter is the issue. Judging by the name of your plasma cutter "pilot arc" "hf" it's your issue.

[bittauto]

thanks for your help did verify it is a high frequency, I should have know better I knew hf causes problems
well i guess I'll be ordering a new plasma
thanks again

[acourtjester]

you want a Blow-back type ignition for the plasma.

[bittauto]

what is a better machine or is it just preference everlast or hypertherm or any others out there, i am mainly use it to cut 14ga aluminized steel tubing

[weldguy]

I believe Hypertherm is the best air plasma but they are expensive and recently hard to get. Have heard decent things about Everlast and it will certainly earn you enough money to get into a Hypertherm in the future if you wish

[tcaudle]

The other factor is USB is not noise immune . it is in my personal opinion, a poor control system for any plasma CNC but especially an HF start plasma While the spec on USB is 15ft that is not in a noisy shop . A double shielded USB cable that is no more than 3 ft long and having the PC and motion device close will help, but a better solution is a connection like Ethernet (made to push high speed data though noisy environment or RS485/RS422 that is a balanced differential signal that can run hundreds of feet (or even thousands with repeaters ) Down side of RS485 is its rather slow compared to Ethernet. USB was made to run computer I/O devices like mice . keyboards and stuff and tiny bits of data loss is no big deal with a keyboard