Help cutting 1" plate

[forhire]

Cutting 1" plate using a cutmaster 151 with an SL100 machine torch and shielded consumables. Tried piercing even though it's not recommended. Lots of slag that often cooled and caught the nozzle. Once started it would cut but it was sloppy at the start. Worked best with THC off.

I tried drilling a 0.125" hole at the pierce location. Torch appears to start but doesn't, just times out. Adjusted the pierce height to 1/16" and turned on THC. Starts well but is having issues about halfway through my test 2" circle. Not sure it it's related to the THC or the low torch height, I suspect the torch rubbed the plate.

Tried a 0.0625" inch hole but it had the same slag issue as no hole.

How do I edge start in version 3.6? I've heard of guys piercing or drilling their plate and then coming back and cutting it. I'd like to do the same.

Played with the plate thickness toggle in the software. No idea what that is suppose to do. Couldn't get it to work.

This is the first test that the torch pierced. It was painful.


This is the one with the the pre-drilled hole. The start is nice but it's messed up in the middle.

[WSS]

You will need at least a 1" lead in and about a .2"-.3" pierce height. Use a nozzle anti stick spray to help shed the slag on pierce. If the hole has a small dia. (2" or less) freeze the thc, otherwise let it track. Go slow. I have a PM1650 and limit it to .75" work, it does well but is hard on consumables.

WSS

[Bigrhamr]

When you say "Torch appears to start but doesn't, just times out." do you mean it is just firing in the air through the hole? If that is the case you'll need to turn the pierce delay off or almost down to nothing so machine movement starts as soon as the torch fires.
(for edge or hole start) I don't know the capacity of your 151 but assuming it's rated for much less than 1" for machine piercing it's very likely that the consumables are toast after a single pierce or failed cut.

[forhire]

Originally Posted by WSS You will need at least a 1" lead in and about a .2"-.3" pierce height. Use a nozzle anti stick spray to help shed the slag on pierce. If the hole has a small dia. (2" or less) freeze the thc, otherwise let it track. Go slow. I have a PM1650 and limit it to .75" work, it does well but is hard on consumables.

Not looking to pierce or gouge start. Too messy around the nozzle and hard on consumables. I'd like to start in the hole or on the edge.

Originally Posted by Bigrhamr When you say "Torch appears to start but doesn't, just times out." do you mean it is just firing in the air through the hole? If that is the case you'll need to turn the pierce delay off or almost down to nothing so machine movement starts as soon as the torch fires. (for edge or hole start) I don't know the capacity of your 151 but assuming it's rated for much less than 1" for machine piercing it's very likely that the consumables are toast after a single pierce or failed cut.

The machine is rated for a 3/4" pierce, which it does no problem. The issue with the deeper pierce the slag cools too quickly and gathers or bunches at the top of the pierce. The consumables aren't looking great but not too bad either. I'll change them this morning and try again.

I just talked to Dynatorch and they said the air firing through the hole prevents the arc transfer command from being sent. They recommended moving the piece center up, half on the material and half off. I suspect that a 0.25" hole would work nice. I'll do some tests this morning.

[WSS]

Originally Posted by Bigrhamr (for edge or hole start) I don't know the capacity of your 151 but assuming it's rated for much less than 1" for machine piercing it's very likely that the consumables are toast after a single pierce or failed cut.

I am glad I bought a Hypertherm! I can get 75 to 100 pierces on .75" with a new nozzle and electrode.

Forhire, you still need a lead in/lead out for quality. Here is a good read on hole cutting with plasma.

WSS

[forhire]

Originally Posted by WSS I am glad I bought a Hypertherm! I can get 75 to 100 pierces on .75" with a new nozzle and electrode. Forhire, you still need a lead in/lead out for quality. Here is a good read on hole cutting with plasma.

Thanks for hole guide. I have some parts to cut today so I'll implement some of the concepts in those.

No issue with the consumables. The electrode looked new other than the change of color. It already had 100+ pierces on it and the nozzle when I started... and dozen or so pierces on 1". I changed the nozzle but the old one looked serviceable. Had you seen the abuse I put it through you'd be surprised. I expected worse. The shielded consumables last a long time.

I understand what you mean about lead in... I took it out of context and thought you intended I ramp into the pierce. This is a test cut. I was lazy and didn't put my lead ins and out on.

The test this morning worked well. I pre-drilled the start location with a 0.25 drill. Set the torch at the edge of the hole. Cut at 9 ipm use the THC. Sanded off the mill scale or paint for good measure. The cut looked good, no anomalies. I do have slag on the bottom side. I might try increasing the speed a bit. Any suggestions?

[forhire]

Success! I had to call Leon and get a solid lesson on why the torch was dragging. He also told me how to salvage the top part and finish it. He saved my bacon. Adjusted the set point voltage up a bit and it's all good. These cuts were done at 11 ipm with a voltage of 127. The chart stated 121 and this low set point was causing the torch to drag on the part. It only took a few minutes each to cut these out.

Thanks for all your help and suggestions. From what I can gather it was the set point voltage all along. Leon said to start a little high and bring in down once your cutting. Stuff I should have known. Experience is the best teacher.