plasma cutter

[Charlie C]

Pile, have you used your air for sandblasting?

I have a 4 cylinder gas engine rotary air comp that I use for sandblasting. After I have used it for a period of time moisture gets into the sand and starts plugging up the tube.

[Pile Buck]

Pile, have you used your air for sandblasting?

Hi Charlie, no I have not! Sorry.
My compressor is only 5-hp, 175-psi, 80-gallon tank. Not what I would consider an acceptable compressor for sand blasting. What little sand blasting I’ve ever done was with a 185 cfm diesel driven compressor.
With you being in Southern Oregon this system may not work for you. Harbor Freights sells a refrigerated air dryer for $299.00 but limited to 140-psi. I think any factory built air dryer that would work on your compressor is going to cost much more . If you decide to built something on this line, might consider placing the copper tubes in one of those small apartment size refrigerators, the ones that are about 3-feet tall. That thought crossed my mind, but gambled on this cheaper version!

[SkidSteerSteve]

Pile,

Something I've done in the past to complement your dryer is to do a two stage regulator system. Since you have a 175 PSI system to begin with, you can put in the primary regulator just before your aftercooler and the secondary regulator after it. This will give you the same effect as an orifice in a refrigeration system. The first stage decompression will cool the air and help force some more moisture out. As long as you are only needing 120-130 PSI, you have some room to step down the pressure. Obviously, it won't be much change, but it might help out just enough on the warmer days. Gotta love Oklahoma....100+F / 80+% humidity SSS

[triggerman]

Nice cooler:

you can put in the primary regulator just before your aftercooler and the secondary regulator after it. This will give you the same effect as an orifice in a refrigeration system.

I like Steve's delta-P idea for forcing the latent change in the coil. I like a delta-V approach, too. Full pressure/flow into the coil then from the coil to a tank where the velocity drop would give better separation. Tank is a bit of a misnomer as it could be just a larger tube. That looked like 5/8" or maybe 3/4" copper in the aftercooler. If you exited the coil into a tank made of, say 3" copper only about as tall as the coil, the resulting velocity change would have the same effect as putting ice in the water for any given temperature/humidity of inlet air without a loss of pressure. Plus the delta-V separation would occur in the cooler and not be passed on to the main tank. Clear as mud?

[calweld]

I finally bit the bullet last year and purchased a Thermal Dynamics 51. I have no idea how this compares in cut quality etc. with other brands, I decided on this particular make because I am portable, the gun detaches from the case with a twist-lock mechanism and can be stored separate on the truck, also I occasionally find myself far from my LWS, anywhere between Oregon, N. California, and Nevada, I wanted the brand with the best likelihood of finding parts wherever I am. I picked the 51 because it was the best tradeoff of capacity vs. weight.

[calweld]

For a quick and dirty air dryer, coil up about 10 to 15 feet of 3/8 copper tube to fit into a 5 gallon bucket, fill with cold water or ice water, have an air/water separator with a bottom drainc0ck on the line coming out. Leave the drainc0ck slightly cracked so the water drips out.

[CV Weld]

I have hypetherm's900 and 1650, also draggoon 38 and lincoln pro cut 50. All depends on your process. I use the drag gun for my on site stainless kitchen work and my hypertherm 900 for my cnc work. you cant' introduce hi freq into the pc from the plasma cutter or your looking for program problems. The hypertherm that Pile was talking about is a great choice. When deciding on a machine you have to look for a few things. First throw out the maximum that it will cut. You are better off looking for duty cycle and pierce capabilities. My hypertherm 1650 is rated at 1.5" thick cut on mild steel ( better off with a torch ). But you have to edge start and in the practical world that just doesn't happen all the time. The 1650 pierces 3\4'' plate and that is what you need to look for as far as what a plasma cutter can do for you. Cost of consumables, service life of a tip and electrode, high freq. or contact start, cost of machine and the list goes on. I have been cnc burning parts going on 12 years and moved to plasma about 6 years ago. My 900 is still going strong and i have my tips custom made and drilled to the size orifice that matches the amps that i use for the required plate thickness. You can make your tips and electrodes last a long time with a bit knowledge. I get way over 700 Pierce's with my electrodes on my cnc machine on 14 gauge plate with a travel speed of 82'' a minute at 45 amps. You need to start your travel while your piercings to keep the spray for blowing back into the tip. Hope this helps. Did i mention dry air. Don www.cvweld.com

[Strider]

Plasma Cutter

The Spectrum 625 is the Plasma Cutter I own. It has served me well in all the projects I've done. I think any cutter you get should be "Stand Alone" in that it should require a seperate compressor which means you can use your compressor for other things and not just for the cutter. Another consideration is moisture in the air you use. The 625 has a small seperator built into the system. I found this out only after purchasing a full sized moisture seperator for my system. In case you are not aware of why this can be a problem, it is that the compressed air passes over some sensitive circuitry and can cause premature system failure. So when looking at a cutter and compressor consider the moisture problem.
Whatever you do don't get rid of your bandsaw. There is no cleaner way to cut a straight line than a bandsaw.