What makes a high definition plasma Vs. conventional?

[Corvus corax]

I have been looking at the Hypertherm plasmas for my CNC gantry type machine, and have settled on a Powermax 1000 for the task. Beyond that power level, my electric wont support the larger machines, and the cutting speed of the larger conventional machines is identical on 1/4 inch aluminum, the material I"ll be cutting most. I've noticed Hypertherm is marketing an upgrade torch for their older Hyperformance plasma, alongside the air plasma machine torches for my series of machines.

Beyond the obvious fact that the high definition torch is designed to run at currents up to 200 amps, and ferrous materials are cut with Oxygen plasmas in high definition, is there any reason the HD torch could not simply be run off the conventional power supply? HD plasma in aluminum is accomplished with air plasma, so no problem there, the currents are the same for the material I'm using, and providing an adaptor to the electrical connections shouldn't be a huge problem, so why could it not be done? It seems the power supplies put out the same voltage and low range current for both systems, so with regards to Aluminum air plasma, what is missing from the equation? It would be nice to have that long consumables life and narrow kerf.

[Big Woody]

Hypertherm has articles on this on their website

http://www.hypertherm.com/technology/high_def.htm

[Torchhead]

The best source on the information you seek is from the manufacturer. Hi def uses a totally different cutting head and multiple gas approach. It has nothing to do with volts and current. All plasmas are arc machines and vaporize metal by creating a high temp arc to the metal and blowing it out with air (simplified explaination). I am sure the HD process takes addtional control electronics so I doubt you could just buy a HD torch and hook it to a conventional plasma.

If you order the Fine Cut for the 1000 you can hold kerfs of .035 and much better detail at slower cut speeds in material up to 1/8" YOu will need to switch to larger tips for 1/4" aluminum.

Once again Hypertherm should be able to tell you the details but even Hy Def plasma is a lot rougher cut that routing, milling, laser or AWJ.

Sometimes a Sow's Ear makes a nice purse.....sometimes it doesn't.

[Corvus corax]

Thanks for the link to the article, Big Woody. From what I can see, there is no reason the HD torch cannot be utilized with a conventional power source. The full benefits of the system may not be realized, in that it will not be set up to cut steel, but the cut quality in aluminum is said to be quite good, using air for plasma and shield. Better results can be had using Methane as a shield gas, and that wouldn't be too difficult to arrange, but the thought of clouds of flammable gas drifting around an ember filled environment is somewhat alarming. The microprocessor control of gas velocity and current at the end of each cut cycle (done to preserve the Halfnium electrode) could be done remotely via the CNC interface present on the powermax 1000. I still haven't found out what that torch costs, though. I'm going to guess somewhere in the $1500- 2000 range.

It looks as if the torch itself is the real secret to the machine. The increase in plasma density relates to the nozzle profile, gas velocity, and fine orifice- all in the torch. Aside from the higher automated functions regarding gas pressure and current ramping, and the obviously higher current output for cutting thicker materials, it seems there is little to separate the two types of power supply. It may end up being fiddly for the first few go arounds, and it may eat a few consumable sets before getting it dialed in, but I'll bet it could be done.

The fine cut consumables are only for ferrous metals, apparently. Aluminum isn't listed as one of the materials to be be cut with them.

[Big Woody]

My new HD is being installed now and it will cut Stainless and Aluminium. The issue is not the torch itself but the cut quality that dictates the process. Oxygen cutting on Al and SS leaves a heat affected zone that may need addressed.
I would also never use a flammable gas so methane is out. Salesmen have stories of shops blowing up there machines when hydrogen gas built up under the steel.
I think that shop air may also be an option for you.

[Corvus corax]

The hydrogen gas buildup under workpieces occurs when cutting partially submerged work on a water table. It is a result of stray electrical current, and hot metal hitting water, dissociating hydrogen and oxygen gas. Given a chance to collect under the workpiece in quantity, it apparently will ruin your day.

I'm assuming Hypertherm is suggesting the use of Methane while cutting Aluminum on a dry table, one that uses a fume extraction system. The amount of Methane would be small, as it is bieng used as a shielding gas, and I would further assume it would be consumed in the cutting process, the excess burning off harmlessly around the torch as cutting progressed.

[Knut]

Your thoughts are my thoughts also on reading about hydef. Didn't see anything about the powersupply mentioned. Of course they use 3ph, but I presume the 1ph supplies are well damped. Obviously you need to supply the extra gas controls that a small machine does not have were you to cut all metals via hydef.

I haven't called to ask the price yet either, maybe they will bump the price up if people try to get around paying the big bucks. Then, they might be nice guys too. They sent me out free manuals on my old MAx 40. Figured I'd have to buy that powermax 1000 also.

My major need is for cutting burr free thin gauge metals. The edge need not be laser smooth, just no burr.

Thanks,

Alan

[Corvus corax]

If you're cutting thin guage ferrous materials, just get the Fine Cut kit. That, and a partially submerged sheet of material (just a few mm of water over the surface) will work wonders when cutting thin steel. Somewhere up here there is some video of a plasma table cutting submerged thin stainless steel, and the results were impressive. Stainless is usually a bear to cut without warpage. His cuts were perfectly flat.

Don't worry about getting a little water on the torch, the air and plasma blows the surface water away from the immediate vicinity of the cut. The gas controls would be one of the easiest parts of the equation. Anyone with enough knowledge and skill to build a CNC machine should be capable of finding the right combination of postflow/ pressures to run a High Def. The three phase power supplies are used because of the higher power capabilites of the HD plasma system. I also think the HD, being an industrial product, is designed to run higher duty cycles at its rated output than a light industrial unit like the Powermax 1000. The output regulation of these small inverters is fantastic. Whaen I bought my first TIG welder, a Dynasty 200, I was amazed how much cleaner the output was from it compared to the industrial 300A TIG I leaned on. Everything about the output from the new inverter circuits is superior to the old transformer based units, with the exception of user servicability. Inverters usually cost more to fix when they break.

[Knut]

There is not a lot of comparative information on the finecut tips vs HD torches.
They do mention near dross free with the finecut, but for what ends? No Photos that you can inspect or specs themselves on edge finish.

I'm looking for no dross, but not neccessarily the very best finish or nitride free for thinner sheetmetals. I'll have to admit never having cut SS less than 18ga with a plasma, used a shear. Need to investigate how that would work without a wet table which you mentioned working so well.

The LongLife feature from hypertherm is primarily from their rampable powersupply controlled via CNC only I presume. They claim their chopper PS are easily microprocessor controlled. If that's the case perhpas you can interface with the Powermax 1000 manual power input to effect the same result. Just a thought.

[dbrown36]

did you give up on the idea of HyDef with a PM 1000? i've been thinking the same thing that you are thinking for a long time now. i bid on a max200 tourch and leads a few months ago on ebay but lost at the lst min. give me a call and let me know what you found 706-681-9292 thanks douglas

[douglasco]

Bump, whats the latest?