Pneumatic Can Crusher
Click the image above for a brief YouTube video of the Pneumatic Can Crusher in action.
Crushing stuff is fun. That's it. That's the whole motivation for this project. I'm not trying to earn recycle income or save the planet. I just wanted to crush stuff.
Click for yet another brief slow-motion mid-construction YouTube video.
DISCLAIMER: This shit is potentially dangerous. The crusher is more than capable of smashing human appendages. It should only be operated by responsible, unintoxicated adults. I built this according to what "looked right" to me. It is otherwise unapproved. If you're dumb enough to replicate my example, you're on your own.
In 2023 I bought a pneumatic can crusher kit off Amazon. The crusher was intended to be used horizontally such that crushed cans drop out by gravity. But with a bit of extra plumbing, the crusher can be mounted vertically as described below. Since this is a gameroom attraction, I wanted the crusher to be free-standing and semi-portable.
First up was the vertical ejection modification. I drilled and tapped the crusher frame for another push-to-connect fitting which was plumbed to the button valve. Exhaust air from the top of the piston goes to the new fitting such that as the piston retracts, the crushed can is blown into the hollow support column where it drops down to the collection bucket.
Vertical ejection modification.
The 5"x4½" hollow support column is about 4' tall and made from 1x dimensional lumber. There's a slot corresponding to the slot in the crusher frame and there's an internal shoot to direct the crushed can back out into the collection bucket.
Column shoot.
The base is just a piece of ¾" plywood. There's a pair of small wheels at the back where most of the weight is concentrated. And there are fixed feet under the bucket. There's a lip around the upper perimeter of the base to help keep the bucket in place and add a bit more rigidity.
Bucket side of the base.
Back of the base.
The crusher head would make a partial seal against the top of a can which could pressurize the can a spray goo. Hence the "Rinse Can Before Crushing" sign. Additionally, I decided to drill some 1⁄8" pressure relief holes through the crusher head. This may also reduce the peak pressure needed to crush a can. I can crush cans down to about 60 psi as compared to the recommended 90-100 psi.
Rinse Can Before Crushing.
Pressure relief holes through the crusher head.
Pressure relief holes through the crusher head.
Some online reviews complained that the button valve fittings were tedious to work with due to close clearances. So instead of mounting the button valve to the crusher frame, I mounted it to the support column with a spacer block. I also mounted the button such that it requires a downward push. This whole contraption is free-standing and a bit top-heavy. I didn't want the push to be toward the back or side to side.
Button valve.
Also note that the button valve is mounted more than 4' off the floor. I rarely have children in my gameroom. But I still wanted the button to be well away from little people. The crusher should be kept away from anyone who is underage, drunk or stupid.
I also added a gauge that indicates pressure atop the piston. The gauge is simply teed off the line to the top of the piston. I believe the actual crush pressure is about four times the gauge indication. The gauge is mainly for additional visual interest. The kit didn't come with enough air line tubing for my extra add-ons, so I bought my own supply of red to make all the connections. Some plumbing brackets were made by welding pipe to steel angle.
Piston air pressure gauge.
Gauge support bracket.
Air supply hose bracket.
The air supply hose goes under a door into an adjacent workshop where it's jacked into the home's compressor system. The compressor itself is out in the garage beyond earshot.
Update: I added more signage as shown below. On one hand, I find it humorous to make the crusher look dangerous. On the other hand, it is dangerous. Some guests appear intimidated. Others jump right in and crush their can.
2024 Updates: Pretty much the main point of this project was to add something fun and visually interesting to the gameroom. I wanted to add a duplex air gauge. No doubt this was influenced by my experience with locomotives, which use duplex gauges for their air brake system. The duplex gauge I found was intended for an automotive air suspension application. The green needle shows the pressure below the piston (retract); the red needle shows pressure above the piston (crush).
Crushing a can.
One thing leads to another. The gauge was backlit so I added a variable 12 volt power supply. I thought a full 12 volts might be over-powering in a dimly lit gameroom. Adjusting to 9 volts was about right.
Variable 12 volt power supply.
Next I cut an access hole toward the top of the column and added a pair of #89-type pinball LEDs. The LEDs subtly illuminate the "mouth" of the crusher and create a brief reflective flash as the crushed can is ejected into the column.
LED assembly.
Wire management on the back of the LED assembly.
Column illumination.
Overview.
As noted above, I installed a pair of wheels at the back of the crusher so it could be moved around something like a hand truck. To that end, I added a handle made from assorted pipe fittings.
Pipe handle.
Instead of promoting Home Depot, I found a plain black plastic planter to use as the collection bucket.
Collection bucket.