Air Comp. mechanics: help me build one around this pump

[YZF150]

I came upon a compressor pump in a shop that was being dismantled. I understand them intellectually, but I don't have hands-on experience at servicing, much less building one. But I'd like to give it a go. The device that I have holds a very strong vacuum when I cup my hand over the intake. The pulley shaft is solid and doesn't wobble. No rattles or apparent loose parts inside. Empty of oil, though, so I don't know about leaks.

Anyway, I'm a little out of my element here, but I think that I know just enough to be dangerous. Let me describe it and I'll ask the experts whether it's worth my effort. I'm interested in learning about these, and so I figured a summertime "hobby class" project might just fit the bill.

Measurements:

* 10" tall.
* Rectangular base is 4x6", 4 holes drilled in the corners for mounting.
* The head has 4 cooling vanes and is 2.75x2.75" square, as well as 2.75" tall above the body of the pump.
* 2 threaded ports for valve access on top, 1" diameter
* 8" pulley
* 8" depth, from outside of pulley hub to the rear of the crank housing.
* Air intake is a circular bell, 1.75" I.D.
* Exhaust(?) is 3/8" pipe nipple, 2" long.
* There is a dipstick with a knurled knob, threaded, 3.5" long.
* Only markings on it were forged onto the body of it: X2-33

I need:

a tank
a motor
a regulator of some kind?
a switch to cut the motor at the desired pressure?

What else?

Anyone care to advise? Would you please provide specifications for the components that I would need, such as 1/3 HP motor with capacitor, for example. --Just guessing, there.

I know that one can buy ready made units quite inexpensively anymore, but I'd like to try to make this one. It looks like an oldtimer that appears to be built like a tank. I'd use it for tires, blowing air to clean, maybe paint sprayer. Whatever.

Thanks much.

 

[MolaKule]

Is this a one-cylinder or two-cylinder compressor?

Most compressors operate very similar to an internal combustion engine. Since an IC engine is basically an air pump, so is the compressor, except in a compressor, there is no ignition and no combustion gasses.

An intake valve opens and allows the piston to suck-in air on the downstroke. On upstroke, the intake valve closes and the piston compresses the air, and then an exhaust valve opens briefly and lets the higher pressure air out to the tank. Since the air is compressed, it is also hot, so many compressor heads have cooling vanes on them. You may also have cooling vanes on the pipe(s) leading to the tank from the compressor head to further cool the air. On two-cylinder units, one cylinder brings the pressure up to a certain level and the other cylinder packs the air to the final level. In other compressors, both cylinders pump air directly to the tank to get a high volume of high pressure air into the tank quickly.

You will need new rings for the pistons and gaskets for the head. If this unit is no longer made, you may have to settle for a conversation piece.

In some areas, however, you may be suprised how many places still carry parts for older compressors and hydraulic units. So get out the yellow pages and search for pneumatics, air compressors, and hydraulics. Case in point. I had an old Dreyco hydraulic pump that a customer wanted rebuilt. This unit weighed 80 pounds and was all cast iron except for a brass-lined backing plate. I went to this small hydraulic supply shop in town and they had every internal piece of the pump that you could want. We determined the brass-lined backing plate was worn. Replaced that and the "ball-bearings" and the unit is still producing 3,000 psi at 35 gpm. This pump was built in 1959. There is something to say for mass and cast iron.

Depending on the the cylinder size and the number of cylinders, the power requirement may go from 1/3 hp to 5 HP. My Industrial Air compressor is a two cylinder unit producing 150 psi into a 20 gallon tank, and uses a 3-Hp capacitor-start motor. I use a 20-30 weight ND synthetic oil.

I hope that helps. And rebuilding is a great learning experience.

[ July 23, 2003, 10:43 AM: Message edited by: MolaKule ]

 

[YZF150]

Molakule, I'm so delighted to hear from you.

This is single cylinder. Judging from the size of the head and cooling vanes, I'd estimate that the bore can't be more than 1-1.25" in diameter, if that.

I'm not sure that I even want to crack it open. It has a heck of a vacuum and holds it. I can suck it onto my hand and lift it. Won't drop. Heavy, too. Built to last. I'm wondering if that cast mark on it, the "-33" part is the year.

Could you address my questions about what other components I should be looking for to build an air compressor, please?

 

[MolaKule]

For those other parts, I rely on

3m.northerntool.com. They have guages, regulators, tanks, motors, etc.

 

[got boost?]

that may be an interesting thing to take apart and play with, but I wouldn't waste time/money on it. sounds like that is a pretty small pump, you can buy a decent compressor for less money than it woul take to build around this pump.

 

[cryptokid]

if you are an ok welder or know how to braze, a large propane tank works really good for an aircompressor.

 

[MN Driver]

Consider the amperage requirements of whatever motor you choose. In my own experience I had a motor give up on an old compressor and I replaced it with the most horsepower that I could get out of about 12 amps of power at 120 volts. The sucker sure made the lights flicker in the garage but it sure pumped that dual-cylinder pump really well. We considered whether or not we should have gotten a 240 volt motor since the compressor would be right next to a 240 volt outlet as well, but the prices for a 120 volt motor was nicer on the wallet.

Personally, since it is only a pump, your project will cost more than it would be worth in terms of the price of buying a new one. With building one you have no warranty on your own work and you need to keep in mind that unless you know what air pressure can do and how to prevent an explosion people could get hurt, high pressure with a decent volume is essentially a large grenade.