first air pump

[urgle the danish cow]

Over the past 6 months or so I have gone through about 4 bike pumps for pressurizing air rifles. The have all broken and cost me a great deal of money to constantly replace and fix. After being fed up with them I decided to just build my own. I chose to buy a check valve at the local hardware store. For my pumps air cylinder I used a length of ¾ inch copper tubing and soldered a threaded coupling to one end to attach to the check valve. The one-way piston I made this part on a lathe For this I brought a piece of aluminum down to size and 1 cm from the end I brought a 1 inch long section down to ½ an inch. On the face of the piston I drilled 2 holes with a center drill to let air pass to into the brought down part of the piston. I then put ½ 13 threads on the inside of the back to attach to an aluminum shaft. To seal I put a ¾ inch rubber O-ring in the brought down part of the piston. This way the O-ring can slide freely on the piston. On the down ward stroke it moves to the back and make an air seal. On the up stroke it moves forward against the holes allowing air to pass, thus avoiding the vacuum.
To the other end of the check valve I added a tee fitting that on one end has a pressure gauge that goes up to 300 psi and the other end has a 3/8-inch ball valve to act as a safety for pressurizing. It can use some more improvements such at reducing the number of fittings after the check valve. Also the piston could be made better and I could use a larger O-ring to improve the air seal for i just used one that was on hand.

i know this isnt a very good pump but i feel like i did alright for a first try

[Gun Freak]

Nice!!
Max pressure?

[evanmcorleytv]

Very pretty indeed!!

[urgle the danish cow]

Nice!!
Max pressure?

im not sure. i dont trust the check valve much over 300 psi

[wyz2285]

i dont trust the check valve much over 300 psi

well I have used my homemade pump with homemade check valve to 1000 psi, a factury build one probably will do.

[Fnord]

well I have used my homemade pump with homemade check valve to 1000 psi, a factury build one probably will do.

That sounds kinda familiar...

[wyz2285]

fine, I have my fridge compressor, and I rarely use my pump to 1000 psi