Thread: Is a plasma cutter feature worth it?

Originally Posted by soundman

....but hell they are a wonderfull thing.

cheers

I admit that the concept peaks the interest of my inner-pyromaniac.

Thanks for your help Soundman.

It was mentioned early that every shed needs a drill press... well they are great, but what I pick up almost every day is a grinder. A good little grinder is indispensable. Don't forget the humble horizontal band saw too - not ideal for wide flat bar, but I would cut more metal with my $300 saw than plasma/cut off disks combined.

I've got a combo tokentools tig/stick/plasma machine and I haven't had any of the so called reliability issues. I had the same concerns pre-purchase and rang Pete at tokentools who explained how the circuits operate in his welders and what this means in terms reliability. My biggest issues is that I hate swapping leads around between welding and cutting - as I tend to do both a lot in the same session. I'd get a separate plasma next time simply for convenience, but that would be an extravagance as it would sit unused in the shed for long stints.

A 40 amp plasma goes great with 10mm steel, but you'd have to play around with air flow a bit and keep your tips clean to get tidy cuts. The metal surface needs to be clean to get a really nice cut and you need to set up a guide to keep straight. When I first started using a plasma I figured it would be great to cut cruddy metal but that's not really it's forte. A cold cut drop saw would be my choice if you could get a good one for this job.

This guy loves his plasma cutter... https://www.youtube.com/user/submarineboat/videos

I agree with others that although they are wonderful things, I doubt that for the job that you are doing they would be as good as a saw. Plasma does tend to leave a rough finish with slag on the edge - easy to clean off but extra work that with a saw is not necessary.
As for your 60x10 section, unless it is a long span or for looks I would have thought you could get away with 60x8 or even 6. Perhaps make up a section with those sizes and see how it looks/ feels. The potential cost saving in material will make the extra time spent worthwhile I think.

Michael

Originally Posted by WelderMick

The metal surface needs to be clean to get a really nice cut ...

One of the plasma's I have uses a pilot arc which seems to overcome a few of the issues with dirty, rust or coated steel. I've even cut steel that had been painted with an enamel paint without a problem.

Originally Posted by WelderMick

It was mentioned early that every shed needs a drill press... well they are great, but what I pick up almost every day is a grinder. A good little grinder is indispensable. Don't forget the humble horizontal band saw too - not ideal for wide flat bar, but I would cut more metal with my $300 saw than plasma/cut off disks combined.

I'm a big BS user as well - it's slow but I can go do something while it's cutting and I love how quiet they are.

Many years go I found a near new Makita cut off saw with a chunk missing of the wheel and a broken vice by the side of the road - it was pretty clear what had happened. I replaced the wheel and fixed the vice in about 2 minutes but only used it a few times because of the shocking noise and I kept it in the back of my shed for a few years until gave it away.

The first thing I usually go for is the BS and then if that's not feasible, the angle ginder with thin cut off whee,l and if that's not feasible the plasma cutter.

I used to have an old table saw with a thin cut off wheel on it and I am really sorry I gave that table saw to my son as it was another quiet (albeit slow) way to cut steel and there was little or no cleaning up of the cut afterwards.

Bandsaws are my weapon of choice for most steel cutting jobs, although I am looking forward to getting my cold saw operational. The downside of bandsaws is that they take up floor space and are harder to pack away out of the way than a drop saw, which is probably an issue for most home handymen.
Abrasive drop saws are the worst from an OH+S (and neighbours) perspective and require eye, ear and arguably respiratory protection as well as being capable of igniting flammable materials. A cold cut drop saw is next up the list and removes the respiratory and fire issues as well as producing less of a burr than the abrasive type. By comparison, bandsaws are benign creatures that don't make large amounts of noise, throw hot sparks or heat the material too much.

A few years ago I bought a CT520 3 in 1 machine which was OK with plasma cutting, scratch steel tig, and stick welding. Last year I hadn't used it for a while on plasma so went to cut some steel and couldn't. Would stop cutting after a very short distance or would not start at all. Replaced tip, nozzle, electrode, swirl ceramic etc and checked the spark gap but no better. Still stick welds all right. Well out of warranty and too far from reliable repairers and probably too costly for a cheap machine repair so later bought Bossweld Invercut 40R with a pilot arc. Tried out on steel, aluminium sheet, bronze and ss and was satisfactory.
Yesterday I needed to cut some curved pieces from galv 3/8" channel which I did freehand following a marker pen line. Turned out a bit rough but ok for what I needed. Will attach a couple of photos to the end of the thread.
I agree that for straight cuts in steel other methods are easier and neater. I have a cold saw, a power hacksaw, and an abrasive cut off wheel but not a bandsaw, but I am lucky to live on a rural residental block with enough room for these, and neighbours not close enough for noise issues.Boswell Plasma cutter.jpgChannel 6X 3 x 0.375 inches.jpg

Originally Posted by Karl Robbers

The downside of bandsaws is that they take up floor space and are harder to pack away out of the way than a drop saw, which is probably an issue for most home handymen.

I built a little lightweight frame for mine when I got it which, despite appearances, is super-stable and gets the work up to the same height as my other benches/tables. With castor wheels it never gets in the way.

https://www.woodworkforums.com/f65/bandsaw-stand-136989

Another alternative is to ask the steel place to cut your lengths to size. Lots of suppliers will do this, even the bigger ones if you ask right. Then you don't need to buy anything.

For me, I have a horizontal band saw and it's great for accurate pipe and tube and bar cutting. I also use a couple of little grinders all the time. And I really, really want a plasma cutter, especially for sheet (where I typically use the grinder).

I got the plasma with my TIG from token - not totally impressed yet. Not managed to get it dialled in and cutting nice at all. Struggled through 5mm plate.

TIG side on the other hand is quite good.

Originally Posted by mac_man_luke

I got the plasma with my TIG from token - not totally impressed yet. Not managed to get it dialled in and cutting nice at all. Struggled through 5mm plate.

TIG side on the other hand is quite good.

Not trying to be funny, but did you remember to connect an earth? If its got a pilot arc, it will cut with that, but you won't get good results and it will burn out the consumables quickly.

In case you've not got a plasma, you might be interested in how it works (well mine anyway). There is a torch with compressed air running through it. inside the torch, they apply HF which starts a pilot arc or plasma inside the torch. plasma is just the 4th state of matter, ie it goes solid, liguid, gas, plasma. For air, its about 20,000C from memory. Anyway, this small pilot plasma, which is highly ionised and conducts well, bridges a gap inside the torch but gets blown out of the nozzle. In itself, it will cut things but not very well. If you hold it up to an earthed bit of metal, the pilot plasma will cut through paint/rust etc, and the plasma will bridge the gap between the outer of the torch and the metal. The main current then flows from the outer of the torch, through the plasma (because its highly ionised) and that's when it really starts to cut. The welder detects the main current flowng and cuts off the pilot arc inside the torch. If you don't earth the workpiece, you will run only the pilot arc and the bits inside the torch burn out quickly because they are only designed as a pilot.

Originally Posted by sossity

Not trying to be funny, but did you remember to connect an earth? If its got a pilot arc, it will cut with that, but you won't get good results and it will burn out the consumables quickly.

yea earth was connected, ill have to have a better play one day.

Originally Posted by mac_man_luke

yea earth was connected, ill have to have a better play one day.

You're probably smarter than me! I use mine quite often to cut stuff like 150x150x8 at a 45 degree angle. Can't do that on my bandsaw. Because i need to cut four straight lines (one on each side of a heavy bit of steel) I had the earth fall off after rolling it over onto the next side, but i never noticed. It will still cut 8mm but it will blow back and spray steel into the nozzle etc if you got too quick. I am embarrassed to say I have cut a whole side of 150mm thinking it wasn't working very well before I noticed. I now know to watch out and recognise immeidately when its not cutting full belt.