Plasma cutter recommendations

[etpm]

About 15 years ago I bought a Thermal Dynamics plasma cutter for use in my machine shop. It is, I think, an 85 amp machine. It will cut 3/4" steel at 10 inches per minute, 5/8" aluminum at the same speed. Once I had to reduce a big machine into pieces small enough for a scrapper to haul off. In that case I cut 3 inch thick cast iron. Not fast. And ugly cuts. But I did it and it was way faster than trying to use a portable band saw. My son and I were truly impressed that we could get the machine to do what it did.
I also know welders who use the Hypertherm machines. They love them. My Thermal Dynamics machine has been trouble free and is easy on consumables. Either of these machines bought used would probably be safe purchases as they both are quite reliable.
A couple years ago the start cartridge in my torch failed. The error code from the machine was ambiguous so I called my local Airgas, which sells Thermal Dynamics parts, and they told me I needed a complete new torch and lead assembly. I'm on the west coast and it was late in the day so the next day I called Thermal Dynamics Tech Support. They said it was the start cartridge. About one tenth the cost of the whole torch and lead assembly. That's what I call good customer support. Airgas seems to hire folks who know little about welding and welding machines, but Thermal Dynamics backs up their machines, even older ones, with good parts availability and good advice.
For casual use you may want to buy a Lotos machine. My brother has one of their TIG welders and it has worked well for him. But if you plan to use the thing a lot I would look at Hypertherm or Thermal Dynamics machines. Only because of my direct experience with one brand and the experience of people I trust using the other brand.
Eric

 

[FrankTailor]

Hypertherm is the way to go. I have 2 hypertherm plasma cutters and am very happy with them. If you intended to make money with it get a high quality unit (read more on https://weldzone.org/bеst-plasma-cutter-with-built-in-compressor/). Used is a good option if you can’t afford new.

 

[5030]

Hypertherm is the way to go.

Maybe, maybe not. depends on the end use and how much you use it. HT's are expensive. I have a computer controlled one I use on my CNC plasma table and it was 5 grand. For hobby use, I'd buy a cheaper one. Hobart has a nice one, so does Everlast and so does Harbor Freight, all for thousands less.

 

[sd455dan]

I can't believe it, but my LOTOS three in One 50 amp plasma cutter with pilot arc has made it over 6 years now. it has gone another 3 + years since the OP started this thread.
Did finally have to replace the plasma cutter torch switch with a generic one, which cost me all of $6

"Rated" Amps are not equal among cheap plasma cutters and more expensive Name brand ones. a 30 amp Hypertherm would outcut my 50 amp LOTOS I would bet on it.

Same goes for higher end MIG welders We have a cheap MIG (under $500) and it is advertised as a 250 amp MIG. I also have a $2K HTP ProPulse 220 (200 amp MIG) The HTP will easily go into spray, yet the so called 250 amp MIG will not.

 

[shaeff]

Love my Hypertherm Powermax 45. The newer version (45xp?) is even better.

 

[BukitCase]

"Love my Hypertherm Powermax 45"

Yeah, me too - This thread has turned into kind of a commercial for Hypertherm, even tho it started as a "hobby" question by a member who hasn't been heard from since November of 2018 -

we HAVE heard from a few members who "rolled the dice" and "got lucky" (or not so much), and the original question WAS only about "which plasma", but I'd like to add a caveat to those reading this who haven't yet "joined the club" and might be trying to decide between plasma and gas torches, or between smaller or larger plasmas -

With a plasma cutter, whether you initially spend $200 or $2000, if you later decide you want to cut thicker material than you originally thought, the ONLY upgrade path is to get a BIGGER MACHINE - and from what I've seen, it takes at least TWICE THE $$$$ (with either budget) to get a serious increase in depth of cut -

Do NOT be fooled into thinking that "amps is amps" (meaning that all "50 amp" plasmas will have the exact same "useful" cut depth) - the REAL workhorse here is POWER, which is Amps TIMES Volts - power factors also enter into this, and this is where companies like Hypertherm spend their R&D budgets. AFAIK, they are possibly the ONLY company that designs and builds their own torches - most just "re-label" generic torches.

Depth of cut vs. Speed of cut - my PM45 (pre XP) is rated for "up to" 1" depth of cut, but it's AGONIZINGLY SLOW (4" per minute) - this translates to 1/16" per SECOND - if you move the torch even SLIGHTLY faster than that, it won't sever. The few times I've needed to cut 1" material, I used a long straight edge marked off in 1/8" increments, and controlled torch movement by counting off 2 seconds per 1/8" - works, but tedious.

It did, however, make a decent cut at that thickness, more than some 50 amp rated machines that're lucky to do a "severance" cut (AKA, ugly) at that thickness..

Other side of the coin - cutting 14 ga. sheet steel, turning the power down to 30 I STILL can't move the torch fast enough without a straight edge to hold the torch against :=)

Depending partly on WHAT you need to cut, plasma might STILL be your least expensive option (Stainless is one example) - those who've tried to cut stainless with an O/A torch will know how well this (doesn't) work...

I mentioned gas torches earlier - they can be a little trickier to get quality results with, but one DEFINITE advantage they have over plasma - my old Harris cutting torch (a GIFT about 50 years ago) came with a couple of tips, and depth of cut maxed out at 2" as it was - last year I went on ebay and DOUBLED its cut depth for $30 (bought 2 NOS tips for it, $15 each with free shipping)

Sorry if this sorta turned into a small book; I figure it's worth it if it helps keep even ONE member from buyer's remorse... Steve

 

[etpm]

"Love my Hypertherm Powermax 45"

Yeah, me too - This thread has turned into kind of a commercial for Hypertherm, even tho it started as a "hobby" question by a member who hasn't been heard from since November of 2018 -

we HAVE heard from a few members who "rolled the dice" and "got lucky" (or not so much), and the original question WAS only about "which plasma", but I'd like to add a caveat to those reading this who haven't yet "joined the club" and might be trying to decide between plasma and gas torches, or between smaller or larger plasmas -

With a plasma cutter, whether you initially spend $200 or $2000, if you later decide you want to cut thicker material than you originally thought, the ONLY upgrade path is to get a BIGGER MACHINE - and from what I've seen, it takes at least TWICE THE $$$$ (with either budget) to get a serious increase in depth of cut -

Do NOT be fooled into thinking that "amps is amps" (meaning that all "50 amp" plasmas will have the exact same "useful" cut depth) - the REAL workhorse here is POWER, which is Amps TIMES Volts - power factors also enter into this, and this is where companies like Hypertherm spend their R&D budgets. AFAIK, they are possibly the ONLY company that designs and builds their own torches - most just "re-label" generic torches.

Depth of cut vs. Speed of cut - my PM45 (pre XP) is rated for "up to" 1" depth of cut, but it's AGONIZINGLY SLOW (4" per minute) - this translates to 1/16" per SECOND - if you move the torch even SLIGHTLY faster than that, it won't sever. The few times I've needed to cut 1" material, I used a long straight edge marked off in 1/8" increments, and controlled torch movement by counting off 2 seconds per 1/8" - works, but tedious.

It did, however, make a decent cut at that thickness, more than some 50 amp rated machines that're lucky to do a "severance" cut (AKA, ugly) at that thickness..

Other side of the coin - cutting 14 ga. sheet steel, turning the power down to 30 I STILL can't move the torch fast enough without a straight edge to hold the torch against :=)

Depending partly on WHAT you need to cut, plasma might STILL be your least expensive option (Stainless is one example) - those who've tried to cut stainless with an O/A torch will know how well this (doesn't) work...

I mentioned gas torches earlier - they can be a little trickier to get quality results with, but one DEFINITE advantage they have over plasma - my old Harris cutting torch (a GIFT about 50 years ago) came with a couple of tips, and depth of cut maxed out at 2" as it was - last year I went on ebay and DOUBLED its cut depth for $30 (bought 2 NOS tips for it, $15 each with free shipping)

Sorry if this sorta turned into a small book; I figure it's worth it if it helps keep even ONE member from buyer's remorse... Stev

 

[etpm]

Oxy fuel cutting is still used for really thick steel. Plasma cutters will not cut 1 foot thick steel, but Oxy fuel will. One thing that plasma excels at is cutting other metals besides plain steel. But stainless steel can also be cut with Oxy fuel. Lay a piece of mild steel on top of the stainless steel, then start the cut. Oxy fuel is an exothermic process and relies on the steel to oxidize quickly, to burn, which releases heat. Stainless of course doesn't oxidize very well, but that piece of mild steel does. And once it starts to burn it mixes with the stainless and so makes it possible to burn too. I have only used this for stainless up to 1/4 inch thick and used 1/16 and 1/8 thick mild steel. And the cut is not as good as it is for just mild steel. But it does work. And is fast.
Eric

 

[BukitCase]

Good call on the mild steel overlay Eric, I'd not seen that - Agree on gas vs plasma tho, my last 10 years I was a crew foreman on top of my instrumentation duties - one of the 2 weldors on my 10 man crew got tired of setting clothes and gloves on fire with some of the heavy demo jobs we did, ordered a EXPENSIVE demo torch - sucker was almost 4 FEET long, IIRC he had to manifold both Oxy and Acetylene on some of the heavier stuff... Steve

 

[5030]

I used to have a Hobart transformer plasma and used the heck out of it and sold it for a good buck when I went with Hypertherm but I went with Hypertherm because it seamlessly interfaces with my CNC plasma table controllers and software and I really don't like incompatibility.

2 grand that's cheap, My Hypertherm was 5 grand but then it's CNC compatible and I use it stand alone quite a bit too. I really like the 'fine cut' consumables. I have no need to cut foot thick steel plate anyway. Last time I cut foot think plate at the shop, I used a thermal lance, not a torch.