Plasma Cutters anyone?

[pajoube]

Thanks Franz, was wondering how they came up with that name. From reading other post on the Plasma cutter I would need to go with a larger unit as I would be cutting and welding 1/8 to 3/8 material.
PJ

 

[Ken_NC]

Kevin-
I am in the process of learning coppersmithing (copper sculptures), and had considered buying a plasma torch to do fine detail cutting of copper sheets. I've never seen a plasma torch in operation, so can you give me an idea of how small a hole you can cut in copper sheet with a Miller like you have? Thanks.
Ken

 

[Anonymous Poster]

Ken, copper sheet will cut the same as steel or stainless, or aluminum with Plazma. Thickness capacity on copper will be somewhat less than steel, because copper dissipates heat better than steel.
When the dealer demoed my Thermaldynamics, he sliced thru a sandwich of steel, stainless, copper and aluminum, and the cut didn't vary between materials that I could tell.
I'm presuming you are talking about thin copper sheet, .050 thickness for the sake of argument, and on that, the cut would probably be around .030 wide with my machine.
Large capacity machines do have a wider cut.
You can also gouge with Plazma, but that might not be applicable on thin sheet copper.
As far as piercing, my machine would pierce .050 sheet with a hole diameter of around .030. There might be some spalling on the back side when piercing copper, can't really say without trying it.
My advice would be to take a piece of your sheet goods to a legitimate welding supplier, and have them demonstrate. That way you'll also get a feel for how the gun fits your hand, and the work you will be doing with the machine.

 

[wroughtn_harv]

Here in Norte Tejas some of the Lincoln dealers have set up rooms where they have all their stuff available for demonstrations.

Probably the most important thing to keep in mind with your plasma torch is you're going to need consumables. This is one of those purchases where you need to go in understanding that your dealer is going to be your best friend whether you want him/her to be or not. So buying at a box store like Tractor Supply, Sams, Home Depot, Lowes, might save you in the short term but it has teeth that will tear you a new one down the road.

I've got Esab and Miller torches. Their parts are available area wide and for me that is important.

This is also the time of year when you can get a good deal from the dealer because the model changes are coming in.

Another thing that blows most folks away is they walk in and pick up an item in a welding supply and almost choke at the price. They just left one of the box stores and it was a third less. So they assume everything in the store is priced accordingly. I never pay list on anything at my welding supply. My minimum discount is twenty percent and usually it's more than that.

Of course the box stores will set you up and clean your clock just as well.

One time (I might be slow but I'm not stopped) I had misjudged an order from a fence wholesaler on some parts. These parts in total run me seventy to eighty cents a unit. On a Saturday the wholesaler was closed and I ran short. I needed a hundred of the units. I went to Lowes and Home Depot. After much crying, hammering, begging, and general snot slinging fit throwing I got HD down to two dollars a unit. If I'd paid their asking price it would have been about three dollars a unit.

I haven't done that again. Like I said, I might be slow, but I'm not stopped.

Do look at the big picture when shopping for a plasma torch. You might get a heckuva deal on the basic torch but if you can't get consumables it's like wanting to start a family and keep your wife a virgin too. You're going to have to consider adopting er adapting as a way of life.

 

[wallysue]

There is an Astro brand plasma cutter laying in the electritians shop at my work. One of the sparkys has it there to try and fix for a friend of his. Turns out its made by some outfit in Italy and some consumables from Daytonamig might fit it. The cutter itself has an electrical problem with no schematics available. Harv is right on the name brand stuff.

 

[TexasJeff]

I am late LOL You have already bought the toy. I have a Hypertherm 900 Plasma Cutter Will cut 1 inch steel starting from the edge or will pierce 3/4 this is hand cutting But I mainly run it on a Plasmacam table cutting 1/8 or less sheet steel or Stainless steel for My sideline business Wall art,entrance signs etc.
It is great Always remember to subtract about 20% from what the manf. claims for there products mine is supposed to cut 1 1/8 steel but let me tell you I have cut 1 inch with it and it is a lot harder than oxy/act but for less than 1/2 I go with plasma above 1/2 oxy/act fires up. On 16 gauge or less plasma with a drag tip cut just about as fast as you can move your hand. I really like clamping a straight edge and cutting against it Cutting a 4x8 sheet in half with a oxy/act is work for me but plasma take about half the time it takes to unroll the hoses and set the regs for oxy/act. and no tip changes for different metal thickness just turn the dial for more or less amps. Each has it's uses and as has been said before Neither replaces the other Main two things are clean/dry air clean/dry air clean/dry air and clean metal

 

[Spencer]

I've got a set of torches and 2 plasma cutters. I rarely use the torches but that is probably because they take a little more skill than the plasma. So don't count out the learning curve. With plasma you only have to learn what to set the amperage to and how fast to move the torch.

 

[brantley]

I bought a Hypertherm 600 about a month ago and have been very happy with it. I have cut several pieces of 2 x 1/2 mild steel bar stock with no problem. There is a little slag on the backside of the cut compared to thinner pieces, but that comes off easily with a few taps of chipping hammer.
The plasma is definitely easier for me to use than an O/A torch.

What materials do you use for templates. I have tried cardboard, hardboard and wood. These all work fine, but there is always some scorching. I need something that will last a little longer and be flexible. I am going to need to notch several pipes as I continue work on my fencing and also other projects that will be using pipe.

 

[wroughtn_harv]

For your pipe there is a product called "sure cut". Some of the welding suppliers carry them. They are clamp on template out of heavy steel that you just follow with your torch.

There is quite a selection. I have one that is for two and seven eighths to cut ninety and forty five degrees. Another to do a saddle and an orange peel. The orange peel is used for making the end into a cap.

In two and three eights I have not only those but also another that is for saddling two and three eighths to two and seven eighths at one end and I believe three and a half at the other.

You can make your own by going up one size of pipe over what you're working with. Make a template and keep trying it until it makes the cut you want. Then cut it lengthwise. Across this cut weld a butt hinge. Then cut it again lengthwise a hundred and eighty degrees over from you first cut.

I usually weld a tab on each side and then use vice grips to hold it closed but you can make a spring over clamp is you're so inclined.

On repetitive cuts with the plasma I usually make a template out of quarter inch steel. The template is made along the principles of one made for routering patterns. It's the width from the center of the cutting tip to it's edge bigger all around.

Then it's a simple matter of laying the template on the material, starting the cut and then just keeping the torch vertical and against the template.

For doing circles you can buy a circle cutting kit. They are all right but I have fallen back to using a circle cutter an old weldor made for me for a cutting torch. It works just fine without all the clutter the circle cutter kits get into.

Another thing I do with the plasma is just draw out what I want with soapstone. Then I set my hood to shade five and get after it.

 

[brantley]

I always enjoy your posts wroughtn_harv.

I have always wondered how the rounded ends were made that I had seen on fencing. I had always assumed it was something cast and added on. I wish I had known about this when I was working on the corner posts and gate posts.

I did a search on google and found a document describing the orange peel at http://www.advancement.cnet.navy.mil/products/web-pdf/ tramans/bookchunks/14251_ch3.pdf. A lot of other neat information in that document as well. After you cut the orange peel, do you hammer it into place cold or does it need to be heated first.

I have seen the templates at my welding supplier, but never looked at them too closely. It looked like some were made of leather. When I was working on a corner posts, I worked out the equation for the saddle cut , cadded it up in Intellicad and cut the template out of a section of round duct work. The template was good, but freehanding along a soapstone line left alot to be desired. O/A or plasma is very unforgiveing of an unsteady hand.

On using metal for a template, I thought I had read some place there could be problems with double arcing in the torch and a reduction of consumable life. So I was trying to stick with non conducting templates. I also expect some templates I want to make may not be available at a welding supply, so I will need to custom make them.