LOL, ok for the record, this whole build is basically "prop comedy!" I think it's hilarious and WAY
overkill. I really don't care about EOTD, my old setup with 1 step down regulator was more than fine for my needs.
As for the step down ratio / pressures . . . those are totally arbitrary. As long as the last regulator is set to 10PSI, I don't think it really makes that much difference. The way I figure, if the first regulator fluctuates by 10%. Then the second fluctuates by 10% of that and the 3rd fluctuates by 10% of that. . . In my head that works out to 10% of 10% of 10% or 0.1% output variation
. Regardless of what the math exactly works out to, this setup is going to be extremely stable.
My needle valve on the end is one that we had laying around at work. I "liberated" that valve off a piece of equipment we scrapped out. It is super coarse, but the price was right!
Rough estimate of total costs: Under $100
$30 for the CHEAP-O welding regulator
$10 for the first step down reg
$15 for the second step down reg
$12 for 0-60PSI replacement gauge for cheap-o reg (replace "cubic feet per hour" which was calibrated to an orifice originally on the regulator)
$24 for 0-30PSI gauges on step down regs
$20 bucks for various supplies / fittings