Spectrum 375 question (maybe)

[Sundown]

A little over a year ago I purchased a Spectrum 375, the operators manual and all the litrature said that the air requirement was 4.5 CFM at 60 PSI so I have been going with that. Looking at the new 2007 Miller catalog I noticed that the air requirement has changed to 4.5 CFM at 90 PSI . It seems to me that no matter how you cut it, that is an increase in the air pressure needed to run that machine. So now it seems that the compressor I have which is on the ragged edge for producing enough air under that old requirement, now suddenly does not produce enough air to run the 2007 version of the same, unchanged plasma cutter. I always just figured that my poor cuts were my lack of knowlegde, now it seems to me that what I thought I knew about my Spectrum 375 may not have been true. OK, I guess I really don't have a question ... just wanted to vent.

[KB Fabrications]

Well that seems like a valid concern. I will be waiting to see what the boys have to say about this one. My 375 Extreme says it needs 5 CFM @ 90 and I have not had much trouble with my shop compressor or my portable Makita in regards to feeding it. Sorry to here about your troubles George. If you don't mind me asking, what kind of results are you getting with your current air set-up?

[Sundown]

Well that seems like a valid concern. I will be waiting to see what the boys have to say about this one. My 375 Extreme says it needs 5 CFM @ 90 and I have not had much trouble with my shop compressor or my portable Makita in regards to feeding it. Sorry to here about your troubles George. If you don't mind me asking, what kind of results are you getting with your current air set-up?

The 2007 Manual lists the x-tream requirements at 4.5 at 90 so at least you are on the right side of the requirements. I suspect that some will have defferent things to say about it, but I will be very suprised if Miller says anything publicly about this, and maybe it's not the big thing I think it is. The machine cuts fine but it seems to leave a bit more dross on the bottom side than I think it should. I don't cut anything more than 3/16" and mostly 1/6" to 22ga so I had just figured that was how it was and I either needed to live with it or get another machine. Air is very dry as I have a seperator going into a Motogard filter at the cutter, with a seperator at the compressor end.

[fun4now]

sounds like a good excuse to upgrade the air compresser to me.
didnt you just get the wife a new rock, looks like its your turn.
FWIW i got a husky from HD and been realy happy with it, should run the 375 no problem.

[Sundown]

sounds like a good excuse to upgrade the air compresser to me.
didnt you just get the wife a new rock, looks like its your turn.
FWIW i got a husky from HD and been realy happy with it, should run the 375 no problem.

You are probably right, I just don't like the rules changing in the middle of the game .

[fun4now]

yep i get ya there. but a new tool is always nice no matter why ya get it.

[Scotth]

George, this change was done because the previous rating caused a lot of confusion among the masses. The previous rating was the plasma gas flow that we measured at the torch head, not the input pressure on the back of the machine. We changed the rating to reflect the actual best case input flow to get the best cut. The cutter will still function at a slightly lower input pressure, but the best cut will occur when the incoming air pressure is between 90 and 120 psi at 4.5 cfm. I hope this answers your question.

[Sundown]

George, this change was done because the previous rating caused a lot of confusion among the masses. The previous rating was the plasma gas flow that we measured at the torch head, not the input pressure on the back of the machine. We changed the rating to reflect the actual best case input flow to get the best cut. The cutter will still function at a slightly lower input pressure, but the best cut will occur when the incoming air pressure is between 90 and 120 psi at 4.5 cfm. I hope this answers your question.

Yes, that does answer my question, at least now I know why and can see what to do about it. Thanks .

[Sundown]

yep i get ya there. but a new tool is always nice no matter why ya get it.

Well ya I can't argue with that at all, btw are you talking about the big 120V husky ?. Hey, I just thought of something, if I got a bigger 240V compressor I might as well get the Spectrum 625 to go with it .

[fun4now]

naaa, i got the 220V version with the 60 or 80 gal tank. it's a lil loud but works really good.
i'll have to go move my son's pic to see the rest of the info on it but it was on sale for right at $400 its been a few years but seems like they have it on sale now and again for the $400 still.
i'm planing on moving the compressor part up into the attic and installing a water separator tube. should keep the noise down and clean up the air. i saw a design for a pipe that reduces water in the system and thought it would be good to give it a try. but even as stock it seems to be pretty good about keeping the air lines water free, it never shoots out any water droplets no mater how hard i push it.
TSC caries the same unit under the camble housfield name i think, yellow paint. the huskiy looked cooler i thought, but the TSC one came with the separator and oiler gage attachments. i had to get mine separately. got the set at HF, nice looking anodized aluminum set. it has a water separator first then an auto oiler after that but i don't use the auto oiler. don't want it in the lines, i oil all my tools at the tool.
all in all i think its a good choice for the $$. it puts out 11+cf pm at 40 psi and 10 at 90 psi and has plenty of volume.
if you decide to upgrade to the 625 give me a shot at your used 375, i got the 125C be for i had air and would like to upgrade now i got the air to run one. the 125 has been a good lil plasma but i want to start building some targets for shooting and it just dose not have the cut capacity to handle the 1/2 or so i need for the bigger guns. and saving up for a new one could be ruff even with selling my 125c for a starter.

[Sundown]

James,

Cool compressor for the money. If I do decide to upgrade the 375 I will shoot you an email first.

[fun4now]

thanks a bunch.now all i gotta do is clear it with the boss
LOL i should be able to resell my spec 125 i kept it looking like new just like all the rest of my stuff.
i forgot to check the rest of the stats on the compresser i was buisy getting my truck unstuck from the mud i call a yard. i gotta git it into the big shop so i can weld on a cat converter so i can get threw inspection, its way over due.
i'll give it a quick once over after i get up in a lil bit i gotta go lay down and eat up some more pills, craling around in the mud is no good for me. good thing i keep a stash of extra pills to cover me when i do stupid stuff like this.

[Rvannatta]

James,

Cool compressor for the money. If I do decide to upgrade the 375 I will shoot you an email first.

they don't make plasma cutters too big---unless you don't have the electric power to run 'em.

[Sundown]

thanks a bunch.now all i gotta do is clear it with the boss
LOL i should be able to resell my spec 125 i kept it looking like new just like all the rest of my stuff.
i forgot to check the rest of the stats on the compresser i was buisy getting my truck unstuck from the mud i call a yard. i gotta git it into the big shop so i can weld on a cat converter so i can get threw inspection, its way over due.
i'll give it a quick once over after i get up in a lil bit i gotta go lay down and eat up some more pills, craling around in the mud is no good for me. good thing i keep a stash of extra pills to cover me when i do stupid stuff like this.

Good luck with the job and be sure to take it easy ...

[WolfMetalFab]

Nice compressor Fun4now, I have the same one in a shed behind my shop, noise doesnt bother me a bit, unless I'm in the shed getting something
With my plasma it calls for 6.7cfm @90psi and I suggest putting a painting type air dryer for the air feed for the plasma, even if the air seems to be dryish
My setup use to have a separator at the start of the run and a 2nd one at the plasma and I was eating up tips bad, so I added a 3rd separator at the plasma, that helped alittle, finally broke down and got a HF painting dryer, but I do have high humidity in this area so that might be part of the problem...

IMHO if your thinking of getting a new plasma unit, why not look at the Hypertherm or Thermal Dynamics units as well, all they make is cutting machines