Torch Height Control Problems

Brian1

Well I finally got my machine working and a few pieces cut that resemble what is on screen but I am having problems with the torch height control. Running MP3000THC Mach and Sheetcam TNG with MP1000THC post on my 4x4 table, Hypertherm 1250 with hand torch and rather new finecut consumables. My switch offset is approx -0.310 and I have entered it into Mach and the Post both. The switch is working correctly in Mach and triggers the z-home light in the diag. screen. My problem seems to be coming from the cut profiles in the thc window in mach but I can not figure it out. I am cutting 14ga mild steel sheet. What it does is it pierces and then raises up to around .5" while still cutting and it does this with Hypertherm 14ga cut profile. I tried changing the switch offsets to 0 and positive .310 and it makes no difference, it keeps trying to cut around 1/2" off the surface. I even changed it to try and compensate for the .5" but it did the same thing. If I change the cut profile in the THC window in Mach to Hypertherm 16ga fine cut it works much better but drags the tip across the metal and consequently moves my 2x3 sheet I am working with. The pierce and cut heights were set to 1/8 and 1/16 respectively in sheetcam. It seems like the cut profiles are overiding the touch off and pierce/cut settings. Thanks for any help!

jeepsr4ever

With the controller on and Mach 3 on screen and without your plasma on press the "TEST" button near the DB9 cable that goes to your plasma cutter. This will put the unit in test mode. From there you will see the torch volts and the preset volts as the torch volts go past the preset volts you will see the up and down buttons moving. This will tell us that everything is hooked up right. Next click the "TEST" button again and verify it came out of test mode on the Mach 3 screen. If your trying to cut 14 gauge at 160 volts you will go too high. For 14 gauge your looking at 75-110 depending on the plasma cutter and the consumable amperage rating.

Brian1

Thanks, I will give that a try in the next few days.

Brian1

Did the test you described and everything was fine. I put the 80amp nozzle on my hypertherm 1250 and proceeded to cut some 1/4" steel just fine. Nice smooth finish, little dross but also a little taper. Torch height seemed to be working good. It was refusing to cut a 3/8" hole though (losing arc and stopping) so I decided to try the fine cut consumables. It is doing the same exact thing as it did on the 14ga steel with the finecut consumables on it. It gets to the pierce height then raises up as it cuts to around 1/2" height again. I am using the 1/4" steel hypertherm 1250 fine cut cut profile in mach with 40amp, 149 arc voltage. I just dont get it

jeepsr4ever

Loosing arc and stopping sounds like a grounding issue doesnt sound related to DTHC. DHC can you confirm your cut height in sheetcam.

Brian1

jeepsr4ever wrote
Loosing arc and stopping sounds like a grounding issue doesnt sound related to DTHC.

I am not saying it was, that was a different problem all together.

jeepsr4ever wrote
DHC can you confirm your cut height in sheetcam.

Yup, cut is set at .0625 and pierce at .125 inches

jeepsr4ever

Check and verify your dont have a bad serial cable from PC to control head. It could also be a com port driver issue verify that in your ocntrol pane/system/hardware/hardware profiles. check to see if you have any conflicts. It is also possible however highly unlikely that the Ubob is bad in the control head. With the test button pressed in do you get the UP,DOWN and ARC OK lit up in Mach 3?

jeepsr4ever

What post are you using as well is it the MP1000? If not change it to the MP1000. Remember always cut counterclockside it is the way the air swirls in that plasma cutter and will give you your best cut.

Brian1

jeepsr4ever;128537 wrote
Check and verify your dont have a bad serial cable from PC to control head. It could also be a com port driver issue verify that in your ocntrol pane/system/hardware/hardware profiles. check to see if you have any conflicts.

I will give those a try soon

jeepsr4ever;128537 wrote
It is also possible however highly unlikely that the Ubob is bad in the control head. With the test button pressed in do you get the UP,DOWN and ARC OK lit up in Mach 3?

Yes, it was doing that in the test mode

jeepsr4ever;128538 wrote
What post are you using as well is it the MP1000? If not change it to the MP1000. Remember always cut counterclockside it is the way the air swirls in that plasma cutter and will give you your best cut.

Using post MP1000THC. Is there a difference between MP1000 and MP1000THC? Not sure if there is even just a MP1000 but I will look next time I have the garage computer online.

I do have cut counterclockwise checked in Sheetcam

Creepy

Is this happening with or without the THC on? Have you confirmed the cutting tip height by measuring with feeler gauge? Check it with THC off to make sure the touch-off and switchoffsets are working fine. Have you put the switchoffset in your sheetcam post? Make sure you aren't using the wrong sheild on the torch tip, the drag tip screws up the THC, you can't get the proper tip height with it. (its made to drag) Ant other updates?

Brian1

Creepy, it happens with thc on. I have not confirmed the cutting height. The switch offset has been entered in both Mach settings and the sheetcam post. Using a normal shield, not the drag shield. Been out of town the last 2 weeks and I have been under the weather the past few days so I havent had a chance to mess with it. thanks!

Creepy

A few things - 1. In cut profiles, shut off the THC from coming on automatically. (global setting) Run a part and confirm the tip cutting height WITHOUT the THC correction. Should be .060", might be a bit different for your 1250. Just shut off in the cut and measure the spark gap. 2. I'm running a powermax45, you've got a 1250...not sure if its relevant, but none of my tip volts are as high as 149V like you have listed. That would make the torch go up, up, up. 3. Possibly install the Smart-Kut software upgrade from CandCNC. It auto-learns the tip voltage preset. TomC. cautions it won't fix a problem, only install on good working unit. 4. Do some line tests. Draw a 6" line and practice cutting it until you get your settings dialed. Cut with the THC off and note the tip volts at a confirmed .060". Use this new 'actual tested' tip volt setting in your cut profile and try cutting the lines with the THC on again. That should give you some clue as to what is going on.