I built a homemade airbrush compressor system for makett painting, because an original compressor is expensive. I picked up a used refrigerator compressor for free from my parent's garage. Air reservoirs were made from plastic bottles (2 x 2.25 L). The system is mostly built from pneumatic parts.
Step 1: Refrigerator Compressor
The refrigerator compressor is a compact part. It has 3 external pipes: intake, outgoing and oil refill. Oil refill pipe was closed by ducktape. A filter should be connected to intake, for example a car fuel filter (missing). Outgoing pipe, ø8 mm, was connected to pneumatic parts by a fiber braided tubing.
There is an electricity box on the side of the compressor, including relay. Relay connectors were wired to pressure switch (E). Electric power connectors were wired to an electric plug.
Warning: before switching on the compressor, take it horizontally for hours.
Step 2: Connecting Pneumatic Parts
Pneumatic part contains unidirectional valve, pressure switch, filter-regulator. Most of them are produced by Camozzi, but other producer can also be selected.
The 3rd out way of filter-regulator was closed by a blanking plug in the factory, I removed it to connect 2nd plastic bottle.
Intake tubing was connected to unidirectional valve (A). Pressure switch (E) was wired to compressor relay. Fittings (C) and (D) were sealed by silicone tape.
Fittings (N) and (O) were connected by pneumatic pipe ø8 mm.
Plastic bottle caps were prepared by a ø10 mm drill bit.
Quick-release coupling (M) was connected to a spiral air hose (P).
(A) tubing fitting, M. 1/4
(B) unidirectional valve, M.F. 1/4
(C) fitting T, M.M.F. 1/4
(D) fitting E, F.F. 1/4
(E) pressure switch, F. 1/4 (NE-MA/ABAC 1 way, 1 phase)
(F) filter-regulator, M.M.M.M. 1/4 (EXTOL PREMIUM Pressure Regulator with Filter and Pressure Gauge)
(G) nipple, F.F. 1/4
(H) fitting T, M.M.M. 1/4
(I) reducing nipple, F.F. 1/4-1/8
(J) prepared bottle cap, ø10
(K) reducing nipple, M.F. 1/8-M5
(L) worm gear clamp
(M) quick-release coupling M, F. 1/4
(N) push in fitting-fixed E, M. ø8-1/4
(O) push in fitting-fixed E, F. ø8-1/4
(P) spiral air hose with quick-release couplings
(Q) escape connector of filter-regulator
(R) quick-release coupling F, F. 1/4
Other parts: plastic bottles, worm gear clamps, pipe, tubing, silicon tape, screws, pop rivet, perforated strap
Step 3: Assembly
A wooden board is the base, compressor and beam of filter-regulator are screwed here.
Beam of filter-regulator is assembled by pop rivets.
Lower plastic bottle is fixed by perforated strap.
Lifting bows are made from perforated strap.
Spiral air hose (P) can be connected to quick-release coupling (M). Reducing nipple of airbrush kit (M.F. 1/4-M5) can be connected to quick-release coupling F (R).
Step 4: Usage
The pressure switch should be set higher than the pressure of filter-regulator. The relay of refrigerator compressor has a time switch: after stopping the motor, it waits at least 1 min to start the motor again.
Escape connector of filter-regulator (Q) should be pulled manually at starting the system, because it's opened by default and only the internal air pressure closes it.
ABSOLUTELY NO WARRANTY. USE IT ON YOUR RISK.