Is insufficient air flow a major issue

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Was shopping for a smaller 120-240 plasma cutter and had narrowed my selection to a Miller Spectrum 375 or TD Cutmaster39. At the store where I eventually purchased a machine, the clerk convinced me to upgrade to the TD Cutmaster52 for a couple hundred bucks more as it was on sale. Since portability is not an issue and I have ample 240 power at my disposal, I went with the 52. However, I should have read the literature first as my compressor only puts out 5.0 cfm (20 gal tank) and the TD 52 calls for 6.7 cfm. I tried the machine today and while it cut fine, I could not keep the pressure at 75 psi--it kept falling off to 70 and then 65. I am assuming that this is not a good thing and will cause problems in the long run with poor cuts and consumables that don't last long. So, am I correct in assuming that I either have to purchase a larger air compressor or trade the 52 in for a 39 which requires only 5 cfm?
Reply:Sounds like it's time for a bigger compressor.  Now that you got it, I'd keep that 52.  Sooner or later you'll need the extra cutting capacity.  You could always find a used compressor and repair or rebuild it.  I bought a 60 gal 11 cfm at 90psi compressor for $75 not too long ago.  Replaced the reed plate for $35 and added a used reg/water trap for less than $20.   Ended up with a decent unit for less than an import pos.  I also rebuilt the pump on my craftsman 33gal at the same time for around $40.  Deals can be had if you look around.My name's not Jim....
Reply:Wow, I gotta find a compressor deal like that!
Reply:Originally Posted by BoostinjdmSounds like it's time for a bigger compressor.  Now that you got it, I'd keep that 52.  Sooner or later you'll need the extra cutting capacity.
Reply:Yeah, your compressor doesn't have -quite- enough sustained air flow for the plasma.  That's why the air pressure is drooping after you cut for a little bit.The solution is more air.  psst, you don't have to necessarily -replace- your air compressor.  You can ADD more air capacity by adding more compressor(s) and plumbing the air lines together.Although a nice big 60 or 80 gallon compressor certainly is a bit more 'elegant'.  It's also a bit more expensive.    The best laid schemes ... Gang oft agley ...
Reply:Originally Posted by MoonRiseYeah, your compressor doesn't have -quite- enough sustained air flow for the plasma.  That's why the air pressure is drooping after you cut for a little bit.The solution is more air.  psst, you don't have to necessarily -replace- your air compressor.  You can ADD more air capacity by adding more compressor(s) and plumbing the air lines together.
Reply:Thanks for all the advice Gents. After searching around the city for a used comp and not finding any deals, I used a bunch of my Canadian Tire money (for our US friends, that means dollar credits) and purchased an upright 60 gal compressor. It puts out plenty of CFMs and works well with the Cutmaster52... certainly no problems with pressure drops now. I think I will also invest in a GOOD water filter so I don't go through consumables as fast. TD makes one that seems to be pretty good unless there are some other suggestions out there.