Welding Tips and Tricks

I am borrowing a friends cutmaster 42. In short I am not impressed. I have used it in 2 different location and here is what I don't like.

the consumables don't last. My LWS says I am getting typical usage (about 40 cuts) from the consumables. I don't buy it. I have used it at my shop, where the air quality is medium. I have filters and stuff but I know they are better ones. At the other shop I have the top of the line air dryers. All the way down to 1 micron with air dryers at the compressor.

In no time the cuts become beveled. This is cutting 3/16 to 1/4" thick plate. It can easily handle that.

Is this typical that I will only get about 40 cuts (yes depending on size, length etc) with the consumables? I don't have a lot of experience with Plasmas so I would like some feedback.

I don't minds spending money for a good product so I am open to suggestions.

Rob

How much of a bevel are you talking about? Plasmas usually have a slight bevel to the kerf, especially on corners.

@Welding Mike. A lot. More than 5°. It starts at 0 to 0.5° off but it rapidly cuts a notch in the consumable and begins to bevel. I machined a spacer to make sure I was keeping the torch 1/8" off of the material and true. It still gives me a bevel. Basically any thing thicker than sheet metal will have evidence of a bevel.

Rob

Right, that is not ideal, but it is common. I'll find a bit of steel cut on our old plasma (a serious big ass thermal dynamics or similar) one thing to consider, is the bevel on both sides, or can it be made to go on to the waste by a change of travel direction.

Really? this is common? Most of the cuts I have seen are pretty straight. Now this is metal I buy or CNC machines I work on. I am not comparing CNC machines to free hand but the operators seem to rarely change out the consumables.

I can see the "flame" come out crooked. What I do is turn the consumable to the angle is in line with my cutting motion. that helps but not when you do a circle or an arc.

Rob

That's about it. Bare in mind, however cnc machines, especially these days might be what's called high definition. (your home one won't be, but maybe talk to a plasma guru on ways to get the best out of it) Meaning dimensions and holes are a lot more accurate. Our machine we used to have couldn't cut a usable hole under 1/2" Dia. Any holes would have to be drilled out later on. I haven't seen any plasma stuff cut for ages and ages. Everything we get is laser cut now. That's the norm for a lot of places these days. At least up to 1/2" thick.

One of my customers has a High Def plasma. Definitely can't afford one of those

I just finished up a project where the parts were laser cut. Really nice. Less warpage than a plasma or a shear.

Rob

I talked to my mate, who used to run the plasma at work. He said that there is really not much that can be done about it, due to the shape of the plasma arc. The only time they attempted to correct the angle was thick aluminium.

Thanks guys for your opinions. I was considering it but now I know

Hypertherm claims to have far superior consumable life, you might consider a HT30 or 45. My ESAB uses consumables pretty rapidly too. I think you mean that the nozzle hole wears and the plasma steam starts coming out at a slight angle causing the "beveled" cuts when the torch is held perpendicular to the workpiece

SouthPaw,

that is exactly what happens. Rather quickly as well.

Rob

Keep in mind that there are many different technologies with plasma cutters. There are older technology systems that never cut a straight edge, there are some very low cost imports that cut decent with a new set of consumables...but the consumables wear rather rapidly, affecting edge quality. There are major brand units (and yes you have to pay more for them) that have some nice torch and consumable technology....even in an air plasma (high definition plasma is another animal altogether!) that can produce excellent cut edge angularity, excellent hole quality and incredibly long consumable life (thousands of feet of cut and 800 to 2000 starts on a single set of consumables). Here are a few pictures of hole quality in 1/4" steel as well as edge smoothness and angularity on 3/8" steel, all cut in my home shop on a low cost cnc machine.

The middle picture shows approx. top and bottom dimensions on holes...showing the taper. The last one is as cut 3/8" steel cut at 45 amps with a Powermax plasma.

Jim Colt

Jim,

Tough, isn't it? To tread the line to not promote a product, when all your recent plasma experience is based on your employer's products?

Steve S.

Rarely is any one neutral. As life experience will usually influence a persons opinion. And as everyone who knows me, I definitely have opinions.

jimcolt
The examples of the plasma cuts are a nice touch

otto nobedder
great watch dog skills

It wasn't my intent to give Jim any grief. I was just pointing out that it's difficult not to have a bias in one's answer when one has extensive experience with a single provider.

I think he's doing a good job of keeping it balanced, but wanted to "poke" him on the issue anyway.

Steve S

Yes....Since I have worked for one company for 37 years I certainly have more info stored in my brain about the products made there. I do have experience with most brands...however if I posted pictures of the cuts from other brands that certainly could be mis-construed as well. I actually have 3 cnc machines in my home shop that were bought and paid for by me and are used for hobby type work as well as occasional paying jobs. I use them online on forums to help those that have similar low cost cnc machines and need help with improving cut quality, regardless of the plasma brand. The pictures I show will pretty much always be using the Hypertherm units that are on my machines, and the cuts will be done at "book specs".....no trickery. If there is dross, slag, taper, it will be in the picture. My point usually is that plasma cutters are not a commodity, they are not all the same and expect varying results. I recommend brands other than Hypertherm when they better fit the needs of the user. The Cutmaster 42 is one I have recommended more than once, as I have some of the other import plasma cutters.

I'm sure that occasionally I need to be reminded to tread lightly in regards to branding and direct comparisons.

Jim

We are all front men for the machines we like. I love my Miller 252 and I am always ready to recommend it. I do understand the forum rules also but Hypertherm makes top quality machines. I have had people kind of giggle when I show them my Powermax toaster...they stop laughing when they see it cut 3/8" steel with a darn near finished edge.

I own a cutmaster 51, just recently I repaired, extensively, three snow pushers and used it often. I beat the hell out of it. I get hundreds of cuts from a tip and electrode; the cheap ones from river weld. I did not see it mentioned but if you want to have good consumable life you need a proper filter.

http://www.tooltopia.com/motorguard-m30-2.aspx


kind of ridiculous to give a number like 'forty cuts', what's up with that. forty cuts a half a mile long or light up forty times. typical nonsense you get out there he probably thought since the machine is a cutmaster 42 that that was the number of cuts you got before changeout.

With all plasma cutters you get a combination of cut duration (avg. time the arc is on per cut cycle) and starts. If you are cutting with long duration cuts you will get more linear feet per consumable set. If you are cutting a lot of small parts with short cut duration you will get more starts, less linear feet cut before the nozzle orifice and electrode hafnium are beyond use. In CNC cutting if you are making parts with no internal cutouts it is always advantageous to use CAM software that can do chain cutting. Start the torch once and do hundreds of parts....dramatically better consumable life when this is done.

Moisture in the air system affects all air plasma torches, some more severely than others. It has a lot to do with the internal design of the torch. In many torch designs moisture (or oil or particulates) will cause consumable failure in 10 to 60 starts, while others will only lose 10% to 20% consumable life. Clean dry air is always recommended, however I see just as many cut quality issues on over-filtered air systems....as often flow restrictions are the result.

Jim Colt