HELP!!!!!

[prattej]

Hey everyone I hope someone can help. I have a TruCut 5x10 plasma table with a hypotherm that my business depends on. Ill be honest I don't know much about it. Lately its been doing some bizarre things. I loaded up a file that we have used for years with no problems. Its basically a 4 foot by 8 foot rectangle with holes. Its starts cutting fine but after cutting the bottom good it goes to the top and on its way back it just takes off. Instead of cutting a straight line, it starts out straight then buzzes for a second and the line goes crooked and jagged. I replaced all 3 Gecko Drives and it still does it. Tried another file that we have also used for years and it short cuts at times. Instead of 3 foot by 4 foot it will be 2 foot by 4 foot. I'm lost and I cant afford for it to be down. Any ideas would be appreciated.

[prattej]

Hopefully this explains the situation better. It starts out cutting the blue line fine but where it turns red is where it messes up

[robertspark]

what are you running, mach3?

have you updated anything (software wise)

[prattej]

Yes running Mach 3 and no we have not done any updates. We have run these programs for years with no issues. Now all of a sudden this is what it does

[prattej]

These two pieces should be identical. The one on the left is cut correctly. The one on the right didnt.

[adbuch]

Assuming your programs have not changed, it sounds more like a possible mechanical issue to me. It is possible that you have a loose/slipping belt, gear, pulley, etc. Are you running open loop, or do you have encoders for indicating your positioning. If encoders, you could have one that is either defective or slipping. I would also check for mechanical binding when moving your table thru the full range of motion with power off and motors disconnected.
David

[cutnweld]

my table (mach3 with servos) started going off in random places all on its own one day, it was worse on higher amperage but did it all the time, I ran a ground rod and that solved it for me.

[prattej]

Honestly I don't know. I think encoders. When the torch veers off on the computer it still shows its following the correct path. What's weird is in drawing it starts at the bottom and the top red line that veers off should be a straight line. That motor controlling that axis should be off. When it goes nuts the tip volts go haywire. When he sets temp volts on computer to 103 it wont go below 113. We can run manually and it works fine

[adbuch]

The computer wouldn't know it is veering off, it only shows the motion for the actual program. Have you checked for any mechanical slop? I would also recommend installing a sharpie pen holder attached to your torch and run this same program with the torch turned off and the sharpie drawing the outline of the part on your metal. If it draws it ok, then I would start looking at possible noise issues from the plasma cutter. If it won't draw it correctly, then look for mechanical issues.
David

[prattej]

Yeah we have a big grounding rod going through concrete into ground.

[prattej]

If the torch is turned off it runs perfectly fine.

[adbuch]

If the torch is turned off it runs perfectly fine.

OK. It sounds like you may be getting some electrical interference from your plasma cutter causing problems with your electronics or drive system.
Have you made any changes recently to your cutter, wiring, cables, etc? Also maybe check your grounding system to make sure that all connections are secure.

David

[prattej]

No changes and grounding is good.

[adbuch]

Tried another file that we have also used for years and it short cuts at times.

Is this "short cutting" with this other file an intermittent problem or does it do it all the time when cutting? Which Hypertherm plasma cutter are you using?
David

[robertspark]

can you post your mach3 profile here please.

it will be the *.pro file with the * being the name of your machine / setup / profile.

you will either need to resave it as *.txt or open it in a text editor (notepad / notepad++) and copy and paste it into a forum reply

insert it within a code block [ code] and [ /code] remove the space between the square brackets and the c or /

[acourtjester]

This is your problem "That motor controlling that axis should be off. When it goes nuts the tip volts go haywire. "
There must be some abnormal arc happening in the plasma signal, you said it acts normal with the plasma off also.
There was a member a short time ago that burned the inside of his torch up, these things generate so much added electrical noise.
Tip voltage going crazy is another indicator to tell you something is not right. I would give a good sniff to all parts of the plasma operation and assemblies.

[prattej]

Thanks for all the suggestions everyone. I will check it out and let everyone know. Adbuch it is very intermittent. Sometimes cuts fine. Other times it goes nuts.

[weldguy]

I was thinking a motor wire beginning to break but If it returns to the EXACT same place it started from EVERY time with the plasma off then I would say this is not the case. This can be easily checked by marking the rails where the gantry and torch lifter start from and ensuring it returns to there.

As these guys said electrical interference could def be the issue, this may get worse as the humidity goes up in the shop, humidity has been bad around here lately.

-be sure your ground clamp is plugged into the front of the Hypertherm unit securely, it's 1/2 turn connection can be knocked loose
-be sure that the 110v outlets you use are properly wired with functioning ground
-be sure any extension cords, power bars, etc. that you are using have the 3rd ground prong intact on the plug