Cant get it to cut

[Brian1]

I have been through all the setup steps in this forum and finally got some more time to spend trying to learn this system and I am having problems, I still havent cut a single piece on my machine.

Basically my problem is once I load the G-code and press start the torch moves into position, touches and then fires to pierce the material and then stops completly. It doesnt try to lift the torch or move, it just fires and then stops and stays in the same place. I have a piece of sheetmetal now with a ton of pierce points from trying different files and x/y locations, luckily it was scrap to begin with. No error codes or messages that I see and I have no idea where to go from here.

Using:
Hypertherm 1250 with DTHC card wired and hand torch
Z home tested good
MP3000-THC-HighRef post processor
MP3000-DTHC-UBOB2 Mach profile
Ground clamp directly connected to the workpiece/sheetmetal

Every once in a while when I load another code or reload the code it will say in Mach that the Fault error is "requested home axis home switch is active...please fix, then home." The z home is however not active/tripped (checked physically and in diagnostic screen) and I dont have any other home switches. This is after it moves into position and fires then stops.

[jeepsr4ever]

Does the Z axis come up for pierce height?

1. Windows XP?
2. Did you load the mp3000 into sheetcam using the wizard?
3. Under Config in Mach 3 in ports and pins whats you kernal speed?
4. DTHC online button in Mach 3 lit up?
5. Are you sure Z axis home switch is not used by any other home switch in Mach3?

[Brian1]

I havent looked closely at it but I dont think the torch height is coming up when it pierces.

1. yes. System is used only for the CNC
2. yes. (still have not got the license for sheetcam so it is the unliscened version but I dont think that is the problem?)
3. 45000hz
4. It blinks green
5. Fairly certain. The other home switches are turned off and in the diagnostics screen the only light that comes on when triggered is the z-home

[jeepsr4ever]

What its telling me is that you dont have the right pierce height in sheetcam. You are sure your Z axis home is working and activated? When you push the z axis upward does the Z home light up in the diagnostics tab in Mach 3?

[sadisticiron]

email me at bobby@sadisticironworks.com and ill help u out. its easier then checking the forum

[sadisticiron]

make sure u get the licence in to that helps alot

[jeepsr4ever]

It sounds like the torch isnt reading the arc ok to move. What plasma cutter are you using?

[Brian1]

What its telling me is that you dont have the right pierce height in sheetcam. You are sure your Z axis home is working and activated? When you push the z axis upward does the Z home light up in the diagnostics tab in Mach 3?

Yes, z home lights up.

OK, I am going to have some time tomorrow to mess with it and on Wednesday. What do I need to check? I did enter a pierce height in sheetcam of around .125" if I remember right for the thin sheetmetal I am cutting.


It sounds like the torch isnt reading the arc ok to move. What plasma cutter are you using?

Hypertherm 1250


email me at bobby@sadisticironworks.com and ill help u out. its easier then checking the forum

Thanks, I will probably tomorrow.

[jeepsr4ever]

Re-check your ground! If it doesnt get an arc ok to move your ground isnt hooked up. Also are you using a current transformer?

[Brian1]

Not using a current transformer. I take the arc ok from the board (screw terminal block) inside the 1250. With the hand torch hooked up maybe the arc ok connections are disabled, I already had to bypass the torch switch found on that same screw terminal block and splice into the hand torch wires.

Jim, is the arc ok on the terminal block disabled with the hand torch hooked up?

[jeepsr4ever]

In the 45 they are still active except torch on and off

[Brian1]

OK I took the cover off the 1250 and got my meter out. I connected the 2 arc ok terminals on the thc card and the arc ok light came on in Mach. Now I connected my leads to the wires coming off the arc ok on the 1250 board and manually cut some metal while watching if the contacts closed and got nothing (no continuity), the arc ok signal is not getting to the thc card.

edit: arc ok seems to be working now from the 1250 but the torch will only cut about an 1" of travel manually by hand before shutting off. Still no arc ok signal in mach. Off to find the hypertherm manual somewhere...

[jeepsr4ever]

Hmmm it should be a very small signal! Is your arc ok hooked up near the torch on and off or on the digital side of the DTHC card...should be on the digital side. Only a current transformer uses the side near the torch on and off.

http://www.candcnc.com/PDF/THCSensor-REV14.pdf

[Brian1]

Yes, it is on the Digital side. Whats puzzling me now is why I can even cut with the torch by hand without it turning off the arc after about 1" of cut. Good air, brand new consumables, good ground. It was working fine for the last project I used it for manually.

[jeepsr4ever]

:-| Give Tom a call he handles our electronics and he can probly troubleshoot you quicker!

903-364-2740

[Brian1]

Thanks, I think I may need to call hypertherm first. I think the relay (or whatever it is) is sticking or bad on the arc ok. Sometimes it is closed and sometimes it is open (both with the torch on and off) and sometimes 1 or both terminals is grounded to the case other times. I have unplugged the arc ok from the thc card and the continuity is still all over the map. I dont know what is going on, I just want to cut some parts :banghead:

[jeepsr4ever]

Hmmm I wonder if you have the right wires. Hypertherm might want you to buy a Auto-interface relay. I dont think you need this. You could go 100% bullet proof and go with a current transformer. They are $12 ea and are easy to install. This gives you divided voltage for arc ok.