Machsupport Forum
Mach Discussion => General Mach Discussion => Topic started by: twicecustom on February 18, 2011, 01:04:46 PM
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I have a problem that has been giving me a hard time.
I'm using steppers, Gecko G540, and CandCNC LCTCH. When the program calls for torch on, it brings up Estop as soon as an arc fires. But If I go to the torch handle and manually fire the torch it doesn't cause a problem. I have unhooked all the motors from the G540 and it still faults out. I have no limit switches hooked up or turned on in the profile. I ran good grounds in the star config to a 7' copper coated rod driven in the ground. I changed Debounce way up and all over the place and it still doesn't work.. Anyone have any ideas???
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It sounds like the THC might be sending an estop to Mach for some reason. I can't think of a reason why a THC would need to estop the system, but I don't know anything about the CandCNC THC either. That or you might have some pins in your configuration crossed up so activating OUTPUT1 is actually sending an estop.
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It works some days, then other days it just wont work at all...
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If it's intermittent, it's probably noise tripping the estop. How is your estop wired? I use a G540 and I have 3 estop push buttons and limit switches all wired in series and connected to the G540 enable. Opening that circuit faults the drive and the drive sends an estop request to mach.
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Wow, I wish I could help you, I have been having the same problem with the plasma cutter on my cnc! I get random windows popping up on the computer and an instantaneous Estop when the torch lights. It has to be noise from the torch. I spoke to a Miller rep and he suggested contacting someone at Miller that may know what is causing this as it could be an internal problem in the plasma cutter. Strange because it worked perfectly fine for years then all of a sudden it won't work right anymore.
Anyway, good luck, I'm gonna follow this thread, interested to see what you find out.
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Did either of you get a new torch. I read some place in a torch pamflit about cnc controling of plasma torches and It said that some plasma torches woud trip the e stop. If I remember right some torches use a high frequncy arc to start the torch. And this caused a feed back through the input cable. they said to make sure all the cable was well sheided and grounded.I cant recall everything that was said but I came away with the understanding of dont use a torch with high frequency starter. might be somthing to check.
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Wow, I wish I could help you, I have been having the same problem with the plasma cutter on my cnc!
Are you using the CandCNC THC also? Just looking for common denominators.
Most machines these days less that 120A are not HF start. I know that TD doesn't go to HF until you get into the high definition machines. HF causes a lot of problems and the manufacturers are starting to realize that. My welder supplier installed a big HF TIG in a hangar out at the airport for welding aluminum. The HF virtually shut down radio communications around the airport. They eventually had to move the machine to a location off the field.
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No, I'm not using CandCNC. No torch height control.
Also noticed my plasma cutter will interfere with the computer just by being near it. It's not even necessary to have a connection to the cnc table, although it is noticeably worse when it is connected.
Maybe some ferrite cores on the THC cables will help you?
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Also, are your cables (thc, motors, parallel cable) all shielded and well grounded? i wonder if it would help to shield the torch cable? Just a few thoughts...
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Everything is shielded on my machine and grounded at the controller. Other than the ground clamp from the plasma, which I connect to the work, not the table, the table itself is not grounded at all. The plasma is a Thermal Dynamics Cutmaster 152.
Sounds like you have either HF start or one of those Chinese plasma machines. My neighbor has a harbor freight plasma and when he fires it (400 feet away in his garage), our TV goes all wacky.
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That was what I was saying . Might not be the cause but if all other options fail just maybe. It is like was just said the last answer a lot of things are made in china and I dont think they are conserned about interferance.
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That was what I was saying . Might not be the cause but if all other options fail just maybe. It is like was just said the last answer a lot of things are made in china and I dont think they are conserned about interferance.
Well, not to hijack the thread, but in my situation I'm running a Miller spectrum 3080 (an older model of their current model Spectrum 875) and it worked fine for several years. Then all of a sudden without any changes to either the plasma or the cnc table or the computer, cabling, etc it just started interfering with the computer. I'm not sure about the specifics of the CandCNC thc so I can't really help the original poster much. If it works occasionally then I would work in the direction of interference in the cabling. Does the THC have the capability to Estop MACH?
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Ive been busy tearing into this and pulling just about all my hair out.. I found my problem, ::) well at least it stops faulting now. Heres what I found out. I'm using a Gecko G540 motor controller, this is tied directly to my computer. When the torch was firing I was using the external relay on the LCTHC that is tied into the G540 and the fault light would trip on the G540 as soon as the arc fired. I came to the conclusion that it was interfering with the onboard relay. My solution was to add another relay, using the onboard one to trip the extra relay that I had installed. It solved the faulting out.
How I came to this, I tried everything, having the motors disconnected, it still tripped. All the limits are disconnected. Re grounded everything including my computer, When I unplugged the wires that are connected to my torch switch it wouldn't fault, but reconnect them and it did. there must be some interference in there to cause some kind of backfeeding into the G540.
But at least my controller box looks good again..
I hope it helps anyone that is having the same problem...
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Glad to hear you got it working. Thanks for the update.
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Put a diode across the relay terminal so that when you hit the button the emf feild will feed back through it . It will work as a electical feed back neutralizer I think you know what I mean. I had the same trouble last year when I built a contol panel for a machine . It used 5 relays and when I made or broke the curcuit on the relay It sent a pulse back through the wiring and made the other relays pulse on. I couldnt figure it out at first either but a electical freind told me what to do Never had any more problems. It allows the electricity to bleed of the coil so you dont get the feed back which can be a lot more than the input power almost 10 times as much.