Do-It-Yourself Shop Air Compressor

[Jerry]

Do-It-Yourself Shop Air Compressor
by Jerry Fields

I needed a source of compressed air for inflating tires, blowing the dust out of mechanical devices, and general shop use. Trouble was that I, as usual, didn't have much of a budget.

A neighbor was getting ready to scrap his old Chevy, which had a York compressor in the air conditioning system. I pulled the York out of the car, decided to try and build it into a useable shop compressor.

I stopped at a 2nd-hand shop and found a used 1/2 hp capacitor-start motor that looked to be in good shape. A stop at a hardware store provided the pressure switch, pulley for the motor, and output manifold used to mount the switch and gauge.

I took a die and threaded the output port of the compressor in a standard pipe thread, added an adapter to make the pipe fit the manifold, and added the pressure switch and gauge to the compressor.

I found a piece of aluminum channel at a metal shop, and mounted it to a 2x6
board. A couple holes were drilled to match the top mounts of the compressor, which are threaded. Bolted the compressor to the channel.

Added a 4 inch pulley to the motor. Located the motor on the board, and measured the approximate length of the belt needed to connect the motor to the compressor. A trip to the hardware store yielded a belt. With belt in place (under some tension) I marked the board for the motor mounting holes. Drilled the holes and bolted the motor, with belt installed, to the board.

Note: larger pulley will yield more air, but may hit the ground when the motor is bolted in place. A smaller pulley will help insure the compressor starts in cold weather.

I routed a power cord through a light switch and into the pressure switch. Output contacts of the pressure switch went to the motor windings. Plugged everything in, flipped the switch, and away it went!

I turned to the air tank, making a "T" manifold out of pipe fittings for it. This would allow me to use the tank either as portable tank or as a reserve tank, just as in a regular compressor, with one line coming in from the compressor and the other going out to the air-powered tools.

Last came the finishing touch, adding quick-connects to the hoses. Be advised that not all connects are interchangeable; buy a full set of the same brand!

It has been many years since I put this rig together, and it has served my general shop needs pretty well. It will not put out enough air for high-volume tools, such as an air sander. (I tried.) Total cost was between $50.00 - $75.00 for everything, including the hoses and quick-connects.

If you are short of money and happen to have a piston-style compressor around, you might want to try this same project.

A comment on compressors: Many newer (and smaller) compressors are lubricated by an additive in the cooling system. The older Yorks (and other piston-style compressors) are lubricated from their own crankcase, making them a better choice for this type of application. However, the piston units can pass oil into the air, and an air filter/dryer is recommended to remove these contaminants before they reach your air tools.

	Main Components 1/2 hp electric motor York piston-style auto air compressor pressure switch and gauge captive air tank hoses Twin hoses allow the tank to be used in-line for reserve air, or as a portable tank. All hoses have quick-connect ends.
	Pressure switch (near gauge) is adjustable for cut-in and cut-out pressures. Current settings are cut out at 110psi, cut in at about 85 psi. A tin can with foam insert handles air cleaning chores. Scrap aluminum channel piece handles mounting of the compressor to the board. Electric motor (1/2 HP, 1750 rpm) was a 2nd-hand store purchase. Compressor was removed from an old Chevy before it was hauled to the salvage yard. Other fittings and hoses were purchased at a local hardware store that caters to farmers. Captive air tank was free from a refigeration shop.
	Output fitting was threaded for manifold. Pressure switch at left. Manual power switch mounted to board.
	Electric clutch on compressor now solid with welds at 4 spots.
	Captive tank manifold is standard pipe fittings with quick-connects for hose ends.