cuts look like a dot to dot drawing

[smutboy420]

Had a new problem pop up today. cant get any lines to cut and the torch when moving along any of the lines just keeps firing and shutting off and re firing over and over along the entire cut path. Causing my cuts to look more like a dot to dot drawing instead of cutting the whole way along the path. If i fire the torch in the air and away from the plate it will stay lite but as soon as I try to cut again and its near the plate it does the dot to dot thing again. I also put in a New swirl ring new fresh tip and electrode and its still doing it.
Only thing that has changed from the other day when things were working great is its now pretty cold in my shop right above freezeing and the plate Im cutting has some surface rust. But i took my grinder to the corner were I have my ground connected so I will get a good ground. So it seems some rust on the surface were im cutting shouldn't be my problem esp as I have never had it cause any problems before. and The cold dont seem to be effecting the torch when I hit the torch button in mach to fire the torch and its stays on and goes off when I press the button just fine.

Has any one else ever get the dot to dot cutting thing before??????????

[beefy]

Have you looked at your gcode. Is the machine doing exactly what the gcode is telling it to do. If so the problem is in the generation of the file. For instance when I import a dxf into Coreldraw, it often comes in as lots of line segments instead of one continuous line, so I have to join all the nodes. Could you be having any issue like that ?

If the gcode basically says "switch torch on" at the beginning of the path, and "switch torch off" at the end, but instead it does what you say, then you need to look at your "torch on" command signal to the plasma cutter, and see if that is switching on and off when it should not be. If that signal is constantly on when it should be but the torch is switching on and off, then the plasma cutter may have a weird problem.

Hope that helps a bit.

I have a quick look at the gcode of every file just to make sure things look OK. There's not many commands to learn for a plasma cutting file and it's a great troubleshooting tool.

Keith.

[smutboy420]

The G code was one of the first things I suspected and checked to make sure there were no extra torch on or off command in it. That was all good. and even watched the screen in mach3 to see if the torch on/off button was also turning off or not. and it would stay on and show that the torch was supposed to be on the whole time. Even when the flame was going out and re lighting. I also could see my arc ok led flash on each time the torch would fire.

I'm going to go out in a lil bit and try again today now that its actually in the upper 30s and nothing should be is frozen. Which I am suspecting that the cold may have something to do with the problem. Like maybe some thing in my air supply causing it. If its still happening today I will be able to rule that out. and if it does still happen I'm going to try and see what happens if I turn of my THC to be able to rule that in or out as the cause.

[beefy]

So far the PC side of things is looking good. You mentioned the "arc OK" light but that is only telling you the arc is established. I would want to see the actual "torch on" signal at the plasma cutter staying steady while the torch is switching on and off. That would prove it's the actual plasma cutter itself.

For instance my Hypertherm needs a dry relay contact connected to the "torch on" terminals. If I remember correctly those terminals have 18v DC when the relay contact is open (torch off) and should have zero volts across them when the relay contacts close (torch on) and short across the terminals. Find out how you system gets its start command and test with a voltmeter. Does everything match what the torch on button on your PC screen is doing. This test will clearly put the fault at one side or the other (plasma unit or PC/electronics) then you know which side to focus on.

Keith.

[Shane Warnick]

I would purge your air supply good. Not sure what you are using for moisture control but even if the outside temp is in the upper 30's you could have a plug of ice or something somewhere that may take a day or two at 38 degrees air temp to thaw out.

Shane

[smutboy420]

For my air supply I use a big homemade inline desiccate filter. I took it inside the house over night to make sure dint have any thing frozen inside causing any blockage. Being it was getting down below freezing at night in the shop.

I "THINK" i may have found my problem. Yesterday when I went out to try again my tables power supply would not turn on. and a few times last week I would have to turn the switch off and back on a few times and then it would come on. So i was thinking I might of had a bad switch. But yesterday when It would not come on I tested the switch and it was sending 120v to my power supply. But the power supply would not power up till I gave it a good smack on the side and it powered up. But as soon as I tried to move the cutting head on the machine I was sounding weird when the motors moved and just the slight vibrations in the machine. Was causing the power in the power supply to flicker and I was also loosing steps. HUMMMMMMM That could of very well could of been making the relay that fires the torch flicker on and off.

So I went to take a close look at the Power supply. and I noticed there is a switch in it for 110 or 220 That normally sits flush with a hole in the housing that seemed to not be flush and sitting were its supposed to. I thought that was strange and just for the hell of it I was going to take a tiny screw driver and make sure it was all the way in the 110v position and just the slightest touch and the dang thing fell inside the power supply. I took the supply off and took it in to the in house R&D lab (aka the kitchen table) and re-soldered the switch back to the circuit board. But noticed some burn marks on metal on the side of the switch and also noticed the internal fuse was blown. So I also re soldered the fuse. But when I got it all done and tried to power it up it still had a short in it. and the plug I was using arced when I plugged it in to the kitchen outlet. So I said screw this and tossed it in the garbage and ordered a new and better power supply. So hopefully when the new one comes I can throw it in and see if the problem goes away. I'm almost certain the problem with the torch going on and off had to be related. esp considering it only happened when the table was moving and I was loseing steps.