Power Requirements:

  • 110v ac wall outlet
  • Draws about 400 watts
  • Aprox. 5 cents an hour to run.

  • Shop Air Compressor Requirements: 

  • (A small shop compressor acts as the first stage and feeds 85 psi air into the ShoeBox) Lowes 2.7 CFM oilless compressor
  • Oilless shop air compressor requiredHome Depot compressor
  • Minimum 85 psi output
  • 2 cubic feet per min. for Max model at 85 psi
  • 2-3 cubic feet per min. at 125 psi for Freedom8
  • Most medium to large oil free air compressors are adequate 
  • Also see our Links page for more options
  • See how to setup your Freedom8 HERE


Fill times are aproximate. Blanks indicate either not measured or not appropriate.



Picture shown below is the complete setup for filling a PCP air rifle.  
You need:
  • Small oil-free shop compressor that puts out 85 psi (6bar).
  • Air hose to connect the shop compressor to the ShoeBox. These are standard fittings. 
  • A high pressure 4500 psi hose with a Parker female fitting to connect to the ShoeBox output. The other end  of the hose needs a fitting to match your tank.

Almost any small shop compressor capable of 85 psi (6 bar) will feed the ShoeBox with enough air.

The shop compressor DOES NOT RUN CONTINUOUSLY and only kicks on a few times during a small tank fill.

Calculate the Fill Time for Your Tank

You must know the area of the internal volume inside your tank in CUBIC INCHES.  Tanks rated in CUBIC FEET are telling you the size of the room full of air that can be stuffed into the tank. Most paintball tanks designate cubic inches, most scuba and SCBA tanks are in cubic feet. 


Cubic Inches of interior volume x 3 = number of minutes to fill that tank to 4500 psi or 300 bar

If you don't know the size of your tank, you can measure the diameter and length in inches to get a rough idea. 

tank radius x tank radius x 3.142 x the tank length = the approximate interior volume of your tank





Shoebox Max
Fill Times (aprox)
PSI=  0-3000  0-4500  2000-3000 3000-4500
Marauder air rifle 18 min. x 6 min. x
Scuba tank 80cf 24 hours x 8 hours x
SCBA tank 44cf 11 hours 18 hours x 3.5 hours
Paintball tank 68 cubic in. x 3.5 hours x 1.2 hours
one cubic inch tank x 3 minutes x x
Fill Times (aprox)
PSI=  0-3000  0-4500  2000-3000 3000-4500
Marauder air rifle 9 min. x x x
Scuba tank 80cf 12 hours x 4 hours x
SCBA tank 44cf 5.5 hours 9 hours x 1.75 hours
Paintball tank 68 cubic in. x 1.75 hours x 35 min.
one cubic inch tank x 1.5 min. x x