I just picked up a Miller 375 Extreme plama cutter. As I have never used a plasma cutter myself.... I have a couple of questions. 1. the manual says it needs air or nitrogen for cutting. so whats better and can I just hook this up to any compressor with a filter? 2. What eye protection is needed while using the plasma cutter? would cuttting goggles suffice? any other recomendations? Thanks!
Shop air with a filter is fine,use one that traps moisture. actually most people don't use any eye protection because the way the cutting head is made there is not any flash on the head side if the tip is within 1/16 of the work. Start with your goggles/tinted face shield till you get the hang of it. Then you may find you can see your cutting lines better with just a clear shield. Play with your setting a bit to get a feel for them. Neat thing is you can use thin cardboard for patterns and you won't burn them up. Use a guide for long streight cuts , in sheet metal it almost looks sheered. If it did not come with the manual get one. There are some consumables on the torch tip that when they are bad the cuts go to hell. I have a Thermodyamics 38 which is the same size machine love it . Don't use it a lot but when I do very happy that I have it.
I want a plasma... I think. I've only ever used one on sheetmetal and was very impressed. But if i got one I would want to be able to cut heavier plate. What would be the thickest material you can cut well without going to a very expensive unit? I know it's a bit of a "How long is a piece of string" question but I'm just after some guidance about what to look for and how much it might cost. Pete
I got one of those (Miller 375 x-treme) last year, and I don't know how I got along without it. I've cut 1/4" with it, no problem at all.
You should have a connection at the rear of the machine for your air compressor. They usually have a water trap and pressure regulator that hooks up there. Check your manual for proper air pressure and flow.
Yes the manual calls out for 90-120 psi there is a hook up for air in the back as you said. just wondering if nitrogen works better. also the unit is portable so was wondering how any of you use it / set it up for portablitly? will a small 5 gallon compersor be enough air for jobs not actually in the shop or close to a stationary compresor?
I've cut a lot of steel with compressed air with no problems. Never used nitrogen. There would have to be a good reason to spend the $ for bottled gas. Maybe for cutting stainless? As far as the compressor size goes, it's all about CFM (cubic feet per minute).
I just use shop air with mine and make sure you darin the water from the system. Plasmas don't like water at all. Just use regular saftey glasses. They cut very quick. Only thing I don't like about the plasma is the cut edge becomes very hard and is almost impossible to machine. I cut some small holes with the plasma and they were just a little too small, they could not be drilled bigger, hard to use a carbide drill do open up the hole.
I've got a Miller Spectrum 375 and am extremely happy with it. I got the plasma cutter, cart and leather torch jacket from Cyberweld.com shipped to my door for about $1100 2 yrs ago. I have severed 5/8" with it but it wasn't pretty and went through a tip doing it. It'll cut 3/8" plate nicely without any problems.
I'm suprised no one here mentioned to not touch the tip against the material while cutting. That just kills me when I see one of the hotrod tv shows showing some guy just dragging the cutting tip right on the material. Even when using a straight edge, you still Do Not want to touch the tip agains the material while your cutting. Carl Hagan
Forgot to mention stainless cuts just fine with a plasma on normal air from an air compressor. No reason to run gass you would have to pay for with a plasma machine. Carl Hagan
Tip touching is fine for sheet metal. Heavier like 12 guage and above use a 1/16 stand off. Cuts better and much rasier on the tip. A 375 Miller is rated at 3/8s will sever 1/2 but slow and not to pretty, my Thermodymatic's 38 is rated the same way. But what ever you buy get a name brand ,you will be happier in the long run. I bought the Thermo over a Miller for a couple of features I like. The tips just snap in, no threads to gauld when hot, and the torch lead is a quick disconect on the front of the machine.
$1100 or so shipped. Shop air, with filters. 60 gallon compressor, I think it's 6.4cfm at 90psi, plenty of air.
I have a smith 75 that will cut up to 3/4 stainless but will cut through 1/2 like butter. The good thing is it will turn down and cut sheetmatal too. It has a 25 foot torch on it. I may want to sell it because I don't ever use it. TP
And I may want to buy it if I wasn't on the other side of the planet. Some good starter info on here guys. I hope ramrod got what he needed. A bit more tech info from those who know would be good. Obviously all the manufacturers use numbers in their machine names. they don't seem to correspond to anything. Is there an amperage range that I should be looking for regardless of brand so I can compare apples with apples? Sorry for the hijack ramrod but hopefully someone will give a bit more info on set up and consumables too. Pete
I have a Miller 375 and it works great. It cuts 3/8" steel plate pretty well, but slowly. It's really slow cutting 3/8" stainless steel, but it works if you keep a steady slow pace. I have cut 1/2" steel with it, but it was pretty ugly and the tip didn't last long. When you cut thick stuff, sort of keep an eye on the sparks blasting out from the bottom of the piece to gauge how fast you can go. If you go too fast, the sparks stop shooting straight down and spray back. I wear some shades that are around a number 4 like for acetylene welding. They work fine if you can do it outside in the sun so you can see what you're doing. The number 4 shades are too dark for bad lighting indoors though. I make templates out of a 1/4" masonite. I sand the edges of the masonite smooth and paint them with carpenter's glue along the edge. That leaves a nice smooth edge that's pretty flame resistant and waterproof, so I can use the same templates over and over even years later. The smooth edge left by the glue allows the torch to drag smoothly and evenly. Make sure the ground clamp is connected tightly to the metal you're cutting. The torch will start to sort of cut even with the ground disconnected, but it ruins the consumables really fast. If you always make sure your ground is good, the consumables last a really long time. The only time I ruin them is when I goof and start cutting with the ground disconnected. One thing I figured out is that you should never cut really heavy metal plate with a brand new tip that's never been used before. For some reason, the tip has to be sort of burned in on some lighter material before you can move up to heavier material. I think the copper is too clean or something when you first start cutting with a brand new tip at full power on heavy plate. With a used tip, I don't have any problems on heavy plate. The cleaner the air, the longer the tips will last. I ran galvanized pipe about 40 feet from the compressor to a coalescing filter which branches off of a down pipe. I drain the condensation from a valve at the bottom of the down pipe. That seems to help a lot and my tips seem to last forever now. Check places like TP Tools for diagrams on how to run air lines to minimize having condensation in the air.
I have a Thermaldynamics 100 and it is awesome. I use it all the time. I have cut 1/2" with it with no problem and it is capable of 1". This is when you would use nitrogen. Also on thinner metals (1/4" and less) you can drag the tip. This is one of the best investments for any kind of fabricator's shop. Size your unit a step larger than you will ever be cutting. I use a ESAB at work that is sized for 3/8" and it goes through alot of tips cutting 1/4". Can't stand sloppy cuts. I bought mine as a wlder supply store trade in. It had approx. 10-13 tips burned through it and I got it ready to go for 800.00 and I've had it 4 years now and not one problem.
Hey Striper, I got one of the cheap plasmas off eBay Oz. I wouldn't do it again. Its got a shithouse duty cycle. The reason for using nitrogen instead of air is to save the Ozone layer. When you run air through a plasma machine it combines the nitrogen and oxygen into various nitrogen-oxides which are ozone depleting.
I've got a Miller 375 xtreme. I am really satisfied with it. It will slowly cut through 1/2" plate and it can look satisfactory if you are careful. Compared to my really poor oxy-acetylene skills it looks like it was cut with a bandsaw. Dave
it suposed to cut thruogh 1/2 steel fairly decent using 220v whats nice about this I think is you can use it on either 120 or 220 volt by switching plug adpaters provided with the unit. I want to play with it this weekend just need to find something to make!
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