problems with EM/HF noise, anyone?

[anthony]

I noticed the PlasmaCam site recommends touch-start plasma torches and am
wondering if anyone has had problems using HF-start torches on their CNC rigs.

i'm still in the design stage (pic attached), and would hate to have to get a new plasma cutter and/or fry my electronics.

-anthony

[Al_The_Man]

Commercial tables have been using them for years including PC based systems with no problem, Shielding and Good grounding is a must.
Al.

[cullken]

I bought my first Plasmacam machine back in 2003 and hooked up a Thermal Dynamics High Frequency start torch and immediately fried the controler and two encoders on the servo motors. After spending several hundred dollars repairing it I traded in The Thermal Dynamics Plasma cutter and purchased a Hypertherm 600 with contact start.
Contact start doesn't mean that it has to contact the material to fire, it means that the nozzle and electrode contact each other and the air blowing through the nozzle creates a spark gap to fire. The Hyperthem consumables last longer than probably any other brand I've tried and the Hypertherm has operated every day since 2003 and has never given me any problems. If you are designing your own machine and controls you can use better electronic (shielded components) than Plasmacam uses and then you should be able to use any type of torch you want.

[aaronpentz]

As al the man states Shielding and Grounding is an absolute must. All of your cables, use metal ampenol plugs and ferrites on some special cables.

Our machines (www.fineplasma.com) are nothing but High Freq start and the only problem we have is machine lockup. Which is caused by a faulty cable or improper shielding. Also all of the cables leading to the machine shouldnt be coiled up under the machine. You need to pull the center in tight. Coils act like antennas for High Freq Noise.

As for frying all of your electrics Make sure you hook all of the cables leading to and from the power unit up correctly. The Plus or Work terminal goes to the table. The Minus or Torch goes to the Torch. Switching the two will cause this if its improperly grounded.