Picture of Ultra cheap pneumatic ram.

This Instructable will show you how to build a cheap air ram for holiday props, robotics or whatever else you want to do with em! You could just go out and get a screen door closer, but for the price of two and a few extra steps, you can make around 10 of them a foot long ! If needed, you can change the length of the cylinder as well as the diameter of the pipe used. Here I am using 1/2“ pvc. If you want to use larger pipe, you will have to do some trial fitting at the hardware store for a piston and seal. Let’s get to it!


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Step 1: Materials and Tools

Picture of Materials and Tools

1/2“ sch 40 pvc pipe

1/2“ end caps (2)

1/4“ steel/aluminum round rod

1/4“ 20 nuts (2)

Air fitting

Plastic bottle cap

5/8 o.d. 5/16 i.d. rubber grommet

5/8x1/4x3/8 nylon spacer

Pvc cement


3/8 drill

17/64 drill

1/4 20 die

Drill/drill press

Sand paper or belt sander


Step 2: End caps

Picture of End caps

Drill a 3/8 hole in the center of one 1/2 end cap and a 17/64 hole in the other.

Thread in the air fitting into the cap with the lager hole and put this one on the 1/2 pipe.

On the pipe, you may need to bevel the inside edge of the opening to make inserting the piston easier.


Step 3: Piston

Picture of Piston

Take the nylon spacer and see if it fits easily into the 1/2 pipe. If not, lightly sand it down so it slides very easy in the pipe. A belt sander is handy for this!

Take the bottle cap and cut a washer the same size as the nylon spacer with a 17/64 hole in the center.


Nice, simple and accurate
oldmicah2 years ago
What do you use to lube the piston?
tobster9103 (author)  oldmicah2 years ago
Silicone spray or grease.