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I am considering the Miller 375 Extreme for a plasma cutter. Can anyone advise me as to the kerf on sheet metal, 18-20 gauge. I want to make figure cutouts and need a clean thin cut.
Thank you
Last edited by photojax; 10-05-2007, 08:16 PM.
Reason: Incorrect machine mentioned
You may not be getting answers because on the main page the title of your thread still appears as "Miller 325 Extreme", and that is confusing.
I cannot help you with this particular machine, but can give you some ideas about mine, which may or may not help.
I have a Hypertherm Powermax 1000 G3. In mild steel, with the standard 60 Amp nozzle, I get a kerf width of 3/32" in cutting from 16 ga. to 3/4" stock. In stainless I get the same kerf in 16 ga. up to 1/4". I have not cut thicker than 1/4" stainless with it yet. This machine has a fine cut nozzle, for use up to about 40 amps. With the fine cut nozzle in 16 ga. stainless and mild steel the kerf width is slightly under 1/16". It produces a very clean cut with a sharp edge and very little dross. I have cut a lot of aluminum with it, from 1/8" to 1/2". The kerf is slightly wider in aluminum as it cuts a little rougher as the thickness of the aluminum increases.
I would think that the 375 nozzle produces a kerf somewhere near the fine cut that I use. Bear in mind that kerf width and cleanliness of cut are a function of amps, nozzle use, clean dry air, and speed of cut. You might also want to check out the smaller Hypertherm plasma cutters while you are considering.
Yes It was a typo I could not edit or delete from the post.
Thanks for your information. If I could get a 1/16" kerf that would be
good. The info about the clean air is helpful also.
I appreciate your reply.
In figuring the outlay for your plasma cutter, pay particular attention to REALLY clean, REALLY dry air. For my machine I have a water separator/filter on the wall with a pressure regulator. Another water separator/filter on the machine cart. This goes into a big MotorGuard filter. From there into the machine. Others advocate a desicant filter. If you don't pay attention to really clean, dry air you will go through consumables, nozzles and electrodes, very quickly. The good filters are expensive but worth it. Not only for the cost of consumables, but as the nozzle oval shapes your kerf will become ragged and dross build up will increase.
Your book on any machine will probably tell you to change the electrode when you change the nozzle. I find this to be mostly horse puckey. Watch the hafnium (sp?) insert in the electrode. I probably go through four or five nozzles for each electrode.
If you are going to be primarily cutting 18 - 20 gauge metal, and don't really need the 3/8" clean cut of the 375 you might want to consider dropping down a size or so in your machine.
Thank you for the information.
I am still thinking about the new Cutmaster 39 that just came out with the 4 year warranty. I have heard that they make a good machine also.
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