Help - Get interference from Plasma on my PC
Hi, I'm new to CNC Plasma cutting and need some help.:confused:
I've build a 3-axis CNC machine to run a router on it and it worked very well.
A while ago I decided to put a plasma cutter on it. I'm using a Thermadyne Inverter type with high-frequency arc start.
The problem is, as soon as I "trigger" the plasma arc my computer pickup interference and either hangup or start with alarm beep and lose control of most functions.
I've tried to isolate the cutting table from the gantry but it doesn't help. Even with the plasma cutter removed from the cnc machine and positioned 10' from the computer the problem remain the same.
I assume the problem is the high-frequency arc, if so, how can I get arround this problem?
Re: Help - Get interference from Plasma on my PC
Hello,
We have recently retrofitted a 6m by 3m S.A.F. Plasma cutting table.
The machine works great however, the arc transfer creates noise which is interfering with our control and P.C.
I will list components used and current grounding techniques below;
Plasma Source : MaxPro 200
Control : Usb Version of Flashcut CNC Controller
Motors/ Drives: Clearpath Stepper Servos (SDSK) type.
Pc: Standard consumer grade Lenovo.
The cnc controller and PC is located in the control cabinet which is located on the gantry.
The Plasma unit is located beside the table aproxomatily 1m.
The plasma hose runs in a cable chain distance of 150mm from other signaling cables.
In this cable chain a usb and hdmi cable are also run to a standalone control console.
At the end of this cable chain (gantry side), the plasma hose is physically 800mm from all other cables on it's route to the torch holder.
I currently have the plasma hose shield grounded on both the Z axis frame and on the plasma unit side to copper grounding rods. The machine is grounded to hypertherms reccomendations. I had this grounding checked be by a third-party company locally. Incase I was missing some (simple) grounding.
Currently the Flashcut Control is losing it's USB connection to the PC as soon as the torch fires.
Any help would be greatly appreciated.
My next steps are
To physically distance the plasma hose completely by hanging it down from above.
but beyond this Im not sure what else I can do.
Is Flashcut the issue as its USB connection?
Would an ethernet controller be a better solution?
Thanks
Andy leahy - Ireland.
Re: Help - Get interference from Plasma on my PC
Not sure if you noticed but this thread is from 2009. You probably would be best to start a new thread. The USB cable you are describing, what does it connect too? the signal generator? If so this is your problem. I believe the max200 is a high frequency start plasma unit, and causes a lot of interference. You might try removing the grounding from the computer that runs the cnc software to see if that changes anything.
Re: Help - Get interference from Plasma on my PC
I maintained a couple of the commercial tables that used a PC based system with a Galil motion controller card, the company installation included a ground rod at the table, the service and enclosure ground was also bonded to this stake.
Never experienced any spurious re-booting etc.
Al.
Re: Help - Get interference from Plasma on my PC
Quote:
Originally Posted by
andyleahy
Is Flashcut the issue as its USB connection?
Would an ethernet controller be a better solution?
Flashcut shouldn't be your problem.... I have used Flashcuts USB version on more than one Plasma Table without issue, and always with Hypertherm units. My current machine has the PC outside of the Cabinet with power supply and drivers, fed with a 10-15 foot quality USB cable. I'd expect problems with that length, but I have none currently. I always ground the plasma cutter right to the plate I'm cutting, and the drives, limits and motor wiring all use common star grounding, with all cable work ONLY grounded in/on the cabinet. Cabinet is bolted right to the machine frame.
First, I'd try a quality USB cable. If that does not help, Flashcut is easy enough to install on another PC or laptop. Install it, copy the Setup file to the Laptop, open Flashcut and load the setup file.
Try running the machine on a longer cable away from the machine. Certainly worth a try as Flashcut is not an invasive program and any laptop will do for a test. If you get better results, You could first swap in a newer or better PC power supply in that Lenovo, reseat all the PC's boards and memory cards, and even use a DIFFERENT 110v power source for it.
One more thing... make sure you have a really good 9v supply for the SIgnal Generator. I've found that it needs a good solid 1 amp or higher wallwart. I've had isues when the PS was not up to snuff.
Lastly, you could give Flashcut a call.... they have put pretty much all their energy in the last few years directly towards Plasma cutting specifically and there is no way they would be successful if it did not work.
Good Luck !