|03-08-2012 10:38 PM|
I have a Century / Hypertherm unit I bought some years back from Sears. This was when plasma's weren't too cheap and available to hobbyists. Mine DOES cut through paint or any other coatings on metals. It is a high frequency unit and requires no contact with the workpiece to operate. I don't even have to ground it with the work clamp, although it is recommended.
The only problem I have with the unit....it's so easy to cut metals and so hard to weld them back together!
I punch out spot weld with it. Cut steel for panels and fabrications. And i got fortunate that consumables aren't too expensive for it. The best advice - buy one with an industry standard torch. Wierd, mail order tip parts will get tiresome.
|03-01-2012 07:58 AM|
I recently purchased a 'new' (Was supposed to be new.. Had fingerprints on the gun, but $400 all in), HF 40 amp plasma (I'm a hobbyest, figuring it would be fine for my needs).
I couldn't be happier with it. Pilot arc, igbt, trafimet gun yadda yadda. For a guy in his garage the odd time, I think it's perfect. Glad I didn't buy an ebay special (the ziptied guns turned me off). Sure this will only cut 1/2-5/8, but I just use it to zip through 1/4" aluminum most of the time.
My regret is not buying one BEFORE my car was almost done.
|02-29-2012 04:56 PM|
|68NovaSS||I'm just a regular car guy, no shop, but when I back halved my Nova, starting out with cutoff wheels and sawsall, for an hour or so, I went out and bought a Lincoln ProCut 25, what a dream machine it is. I used it to cut my hood for the blower as well, and have used it quite a bit for minor fabrication, stands, bracket stuff. The only issue I had was most of my household breakers were only 15A, if you turn it up you could use a heavier circuit. It doesn't get much use lately, but it's there if needed. Some would consider having one as overkill, or an unnecessary luxury, but....|
|02-20-2012 01:17 PM|
Plasma cutting with one of the major brand torches (like Hypertherm) is easy to do by hand as you can drag the torch on the plate or sheet being cut....or guide the torch along a template.....a piece of cardboard works well. These newest systems have a varieaty of different nozzles for different power levels that allow you to fine tune the cut quality for the thickness being cut. Here are some pics done with a 45 amp system on a 4 x 4 cnc table.
1st pic....120 1/8" shims cut in 23 minutes. 2nd pic, 3/4" steel, 3rd...3/8" steel, 4th...1/4" steel, 5th, aluminum
|02-18-2012 08:40 AM|
I have my ways based on what I have learned and done but I am not going to say it's the right way or the only way.
I will say if you can control your hand with CNC precision out of a plasma or torch can be mind boggling. This is an oxy torch:
|02-18-2012 08:34 AM|
We all have opinions and this thread sure drives that point home. I have several cut off tools with different sizes and speeds available for cutting metal. Same with grinders. Also have a couple of different size acetylene torches. But the small plasma cutter has become the tool of choice. To me, it is quicker, cleaner and in the long run, the cheapest tool to use. $1.50 and up or a 3"X1/16 good cut off wheel gets expensive fast when making long and complex cuts. I can usually have the cuts made and trued up in the time it takes to change wheels on the air tool. I would say if I could only have one tool, then it would be the angle tool, but being around as long as I have, that is not a problem.
|02-17-2012 09:12 PM|
The plans are in "The racers guide to fabricating shop equipment" Stiil in print and the plans show a method of adding a motor drive as I recall..
|02-17-2012 02:13 PM|
|02-17-2012 10:39 AM|
Something I have been thinking of is building a pantograph to mount my plasma so then I could make a pattern and trace the pattern with the plasma...I have the plans for the pantograph just have not as yet built it..the original plans call for the use of a torch which I used many years ago and it worked well for making those flame cut parts we used to make..
|02-17-2012 08:30 AM|
I will also say a plasma is in general safer then a grinder. Having said that, I will tell you about an accident with the plasma which could have been a lot worse.
In the previous post the first photo I was going to cut the gauge for the air dam. I had all my safety equipment on including face shield, respirator. I was cutting a few things and the plasma puts a lot of smoke.
My equipment was sliding down my face so I grabbed my head repositioning my equipment. I did it so fast I just wasn't thinking. I had the plasma in my right hand and it was pointing directly at the side of my head above my ear.
Then all the sudden I heard the air valve click (Which means I accidentally pulled the trigger). When I head that noise I thew my arms straight out dropping all equipment. Simultaneously the plasma fired blowing the tip away from my head as I let go.
I lost a 2" circle of hair and a bit of a scab on my head. Dumb dumb dumb. I just sat their with a burnt head laughing at how stupid that was. You can see some where in the bottom of that photo is a small lock of hair.
|02-17-2012 08:21 AM|
I could not wait to get my plasma cutter. After using it for different projects I see I over rated my need for it. You cannot duplicate the precision of a hand held grinder with a cut off wheel; well if you were a robot you could.
My uses for the plasma ended up being quick hack jobs mostly. It is nice to quickly cut a general shape, lop off a piece. For instance this is a gauge used to make the contour of the air dam. The inside was cut with accuracy with a grinder but the tool itself was cut out of the plate with the plasma.
You can gain some accuracy with a template and a steady hand but even then the metal still needs some clean up work. Some people like working hard to get a good plasma cut and that's good but I still prefer the grinder when i can.
I have also found the plasma useful in cutting things I could get no other tool in. I had to clear some webbing from inner body structure to make way for a bracket. No grinder or cutter would fit in where I put the plasma.
As far as grinder accuracy you might be surprised. I have no trouble holding 1/32" when cutting with a grinder and provisions can be made to be even more accurate. The 3rd image is a cam for a single cyl engine I made cut from a 1" thick plate using a hand held grinder.
Please excuse the fact I have no guard on my grinder. Yes it's a bad idea and I have no excuse for it:
|02-17-2012 07:56 AM|
I work part time in several race car shops and a trailer shop. The Miller plasma is really a valuable tool. We make patterns from 1/4 and 3/16 masonite and just cut the parts out. It works great for circles especially...we have hole sizes up to 6" that are used often and many other shaps.
I cut suspensions off trailer often. These are full of rust and grease and other not so nice stuff from horses and cows. Works great ans is fast.
We still use the O&A torch to heat nuts and for cutting the plasma can't reach.
One thing we found was that if you cut 4130 steel with the plasma the edge gets very hard and will kill a saw blade or drill very quickly.
I also use the grinder and cut off wheels extensively.
So all in all the plasma is just another usefull too, but not and end all.
|02-15-2012 08:47 AM|
I bought a Hypertherm unit, and, have been happy with it, although like most Posters here I use cutoff wheels-more and more I find myself using my 4 1/2" Milwaukee with a cutoff wheel for the thin stuff.
If I have to cut out a lot of metal, then I will break out the Plasma, or when I am cutting thick stuff over 16 Gauge-it's just faster, and the clean-up (for me) is about the same, cut-off wheels vs. Plasma.
My Brother-In-Law has started a company where he makes replacement power seat adjusters for Cars where you can't buy them separately, (where you have to buy the complete adjuster assemblies from the Dealer-Dodge Pickups, Mustangs and the like), and he has been using a cut-off for this for about 2 Years or so-he came to visit and I let him try my Plasma-he fell in love (as his cuts are of the 1/8"+ variety, and it has saved him a lot of time.
Would I buy one again or recommend one? Like Ogre suggested, unless you are doing more than one Car, or are doing a tremendous amount of customizing or chopping, I think you can "get by" with a variety of cut-off wheels-would I sell mine? Not on your life!
|02-15-2012 08:34 AM|
|11-22-2011 08:06 PM|
|Crosley||I bought a Thermal Dynamics cutmaster 38 a few yrs back. Way kool tool once you get used to it and how to cut stuff.|
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