Pierce Height wrong

[weldor2005]

I've got a problem with my height control not getting the right height for piercing, but seems to correct itself as it moves along the cut path. My setting is to pierce around 0.15 and cut at 0.06 as recommended by Hyperthem. The height at pierce is no wear near that (too high) and results in not piercing or cutting for several inches until is senses its way down to the appropriate cut height.

This started once I put 26 in the Material thickness spot for cutting some 26 Gauge Galvanized sheet. Hasn't fixed itself with any materials since then.

Here is a video..

http://www.youtube.com/watch?v=6ehRC9al ... Fw&index=2

It cut the first piece fine, and the sheet warped a lot as can be expected. Then around 0:35 seconds into the video and locating and piercing the second part it doesn't do so hot, and hasn't since then.

Added information is that I've got all the Height Control unlocked for my machine.

Any suggestions?

[jimcolt]

David,

Since you have the DHC2 with the full advanced height control you need to remember to set everything in the height control and machine control menu correctly. The Plasmacam height control is a great height control with features similar to height controls on industrial machines that cost over $80k, but make sure you:

- Always input the material thickness
-Always input the pierce height
-Always input the cut height
-Always check the calibrate boxes for z axis and arc voltage shift whenever changing consumables or material thickness.
-Make sure the ohmic sense function is active and height control is active.

The calibrate re-zeros the torch position on the first cut, then it will be correct for all of your cuts. If you have a high pierce height...your cut height (with a Plasmacam) will also be too high...and that will cause the top dross and warpage that I see in your video.

Jim Colt Hypertherm

[weldor2005]

Thanks for the reply Jim, I'm sorry I missed you at the Skills Competition in KC.

I thought that I had been doing all of what you have suggested all the time, but I will try again. In that video, so that I could get accurate cuts and less machine whiplash, I cut the 26 ga at 30 amps and the book specs for my 45 amp hand torch that I use.

what really thoughts me for a loop, is that once cutting it leaves a wonderful cut. That was the first time I ever cut anything that thin, and since then on thicker material it hasn't been right. I've cut holes in 3/16" plate to test some settings, have changed consumables and everything. I got a job coming up cutting a sign on some 3/8" and because of this I have been cutting anything that I'm not afraid of warping with the sense to pierce off, and use the contact method just fine. I just wish I didn't have to go backwards to do this.

I will keep tinkering, just wanted to try and resolve this before I cut this sign this weekend.

One last question for the plasmacam users, when putting in material thickness, and it askes for Ga/inch, what do you typically input? on 16 ga I always put in 16 no problem. on other gauges it seems to like the decimal more?

Thanks,

[tnbndr]

Just a thought, but instead of putting in 26 (gauge) for the material, should you be entering the decimal equivalent?

[jimcolt]

The Plasmacam software can distinguish between gauges or decimal thickness automatically.....you can enter either.

Just a thought, but instead of putting in 26 (gauge) for the material, should you be entering the decimal equivalent?

[weldor2005]

Just a thought, but instead of putting in 26 (gauge) for the material, should you be entering the decimal equivalent?

I don't know whether or not this was the issue, but even if it was surely would've thought that it wouldn't translate into a different job on 3/16" when i put in 0.188?

I under stand or think I do what Ohmic sensing does, but someone please enlighten me as to the importance of telling the machine how thick the material is sense it is simply sensing the surface of the material? Its not trying to deduct the difference of the material thickness form the zero position of the bed. Just a thought that might lead to an answer, never know.

[jimcolt]

I occasionally forget to check the calibrate z axis boxes when I change consumables or material.....and then the height control pierces at incorrect height and cuts at incorrect height.....tips me off to go back into settings and check those boxes. Every first cut with any plasma system you should be watch (through glasses) the pierce and cut height. Most important two setting for good cut quality.

Make sure you are using the machine torch shield on your Powermax45. The key to not warping thin material (there will always be some warpage on sections with close cuts due to heat buildup) is to cut at very high speed and at the right height. Warpage is caused by:

- speed too slow
- Amperage too high
- torch height too high.

I noticed in your video some top dross....that indicates that the torch is too high.


Jim Colt Hypertherm

Thanks for the reply Jim, I'm sorry I missed you at the Skills Competition in KC.

I thought that I had been doing all of what you have suggested all the time, but I will try again. In that video, so that I could get accurate cuts and less machine whiplash, I cut the 26 ga at 30 amps and the book specs for my 45 amp hand torch that I use.

what really thoughts me for a loop, is that once cutting it leaves a wonderful cut. That was the first time I ever cut anything that thin, and since then on thicker material it hasn't been right. I've cut holes in 3/16" plate to test some settings, have changed consumables and everything. I got a job coming up cutting a sign on some 3/8" and because of this I have been cutting anything that I'm not afraid of warping with the sense to pierce off, and use the contact method just fine. I just wish I didn't have to go backwards to do this.

I will keep tinkering, just wanted to try and resolve this before I cut this sign this weekend.

One last question for the plasmacam users, when putting in material thickness, and it askes for Ga/inch, what do you typically input? on 16 ga I always put in 16 no problem. on other gauges it seems to like the decimal more?

Thanks,

[weldor2005]

Well after looking over all the settings, I didn't have the "Error when material not sensed" clicked, So I clicked that this weekend, and now I'm thinking my problem is that I cannot get it to sense the material. I tried new consumables, tightening/loosening of the consumables, and made sure the little connector was clean and getting a good connection. So today, once again I was cutting without

Any first points to look for?

[jimcolt]

Make sure the ohmic sensing wire is conductive all the way to the torch shield. You can plug the wire on the wire connector on the retaining cap, and check continuity with a meter. Sometimes the little tab between the retaining cap and the shield needs to be bent slightly to make contact with the shield.

Or, you can plug another piece of wire into the ohmic wire, then cycle the machine and as the torch is indexing toward the plate....touch this wire to the plate (to complete the ohmic circuit) ....the torch should stop downward motion and retract the distance you have set for pierce height.

Make sure the "sense the plate" box is checked.

If all of the above show that the circuit is not working....you could have a bad connection in your cable between the plasmacam control box and the plasma cutter.

Jim Colt

[weldor2005]

Make sure the ohmic sensing wire is conductive all the way to the torch shield. You can plug the wire on the wire connector on the retaining cap, and check continuity with a meter. Sometimes the little tab between the retaining cap and the shield needs to be bent slightly to make contact with the shield.

Or, you can plug another piece of wire into the ohmic wire, then cycle the machine and as the torch is indexing toward the plate....touch this wire to the plate (to complete the ohmic circuit) ....the torch should stop downward motion and retract the distance you have set for pierce height.

Make sure the "sense the plate" box is checked.

If all of the above show that the circuit is not working....you could have a bad connection in your cable between the plasmacam control box and the plasma cutter.

Jim Colt

Okay, I got around to trying some diagnosis here...

I used another wire to jump the ohmic wire to the material, and it would fault out saying that the torch hit material while moving. So with this I would believe that the wire going to the control box isn't screwed up.

However, I still even after making sure that the tab is in contact with the shield am not able to get it to sense the material accurately. I did get it to cycle once, and on the second pierce sense it faulted out again not being able to sense material. I was doing this testing with the plasma cutter off and the cutting off on the control module, if that makes a difference. The time that I got it to cycle once was after hitting the zero z shift button, and even with this cycle it wasn't close to where it should have been.

[weldor2005]

Bump * Problem still exists. Cut some 3/8" plate and had a nice bow in it, forced to cut it by contact method and this left some undesirable dross cleanup as the outsides were left cutting with a larger gap than I would like.

[weldor2005]

Problem solved with a software update and factory settings reinstated, must have been something I did.

Thank you Jim Colt for your guidance.