A Lesson in eco-friendliness

How to recycle Aluminium (Aluminum) cans.


As a family and household we strive to be eco-friendly and kind to the environment. This involves many things, being efficient over energy use, driving an energy efficient car, bicycles being used when they can. We have solar panels, a wind generator and the current project under design is a home plant to convert used vegetable oil in to diesel which will be used in a generator set. On top of all that we recycle all we can. Which leads to an interesting quandry ...
Our local council, in its infinite wisdom, provides a home recycle bin. Wonderful I hear you say. Except it's 35cm x 45cm x 30cm (about 14" x 18" x12" for our American cousins), ie, it's TINY! We're a normal family, I drink soft drinks and beer, my good lady drinks soft drinks and alcopops, my daughter drinks soft drinks and alcopops and my step son drinks a lot of soft drinks. That's a lot of cans ..... we can fill the recycle bin (shoebox) with cans alone let alone paper and recyclable plastics! So .... Yerman and I put our heads together, drank a lot of tea, smoked quite a few cigarettes and came up with Crush-a-Can!

Welcome to Crush-a-Can Mk 1.
Click any of the pictures to see the full size version in a new window.

As you can see, the basic principle here is a big pneumatic cylinder mounted in a sturdy extruded aluminium frame with an aluminium base to crush the can against and a steel end plate on the end of the cylinder to do the crushing! Yee har! Dont' ya just love wanton destruction!

Now before we crush any cans let's talk about safety. Be sure you have the instruction manuals for all your dangerous tools and equipment in a safe place. That way, if you manage to do yourself serious damage you'll know where they are when someone yaps at you about safety.

Most important of all, make sure you've got a really silly looking pair of biggles goggles.


Here we see a close up of the business end of Crush-a-Can Mk 1.

For those interested the cylinder is an SMC Pneumatics 32mm bore x 200mm stroke guided cylinder. The guide block and rods (the large aluminium block and the 2 rods on either side) are normally there to provide an extremely accurate linear action for the cylinder. It this case it just looks cool!

Being serious about safety for a moment ...

You'll see from the first picture there are two large red buttons on either side of the top of the frame. These are part of a two-handed activation system.  Unless you've got hands like the hulk you can't operate it with one hand and the buttons must be pressed simultaneously or the Crush-a-Can Mk 1. won't operate.

You can see the plumbing and switches in the picture to the right.

Here's a more detailed picture of the control system.

A quick description. The T-connectors (middle top) take in mains air and distribute it to the switches, two-handed safety switch and 5/2 valve. When you press the two buttons, air flows to the safety switch (bottom middle right). If you have pressed the buttons simultaneously air flow to the 5/2 valve (bottom middle left). This is basically a changeover air is either supplied to one output or the other. In the off position it holds the cylinder retracted, in the on position it extends the rod. The more air pressure to more force it will apply. Ours is running at 100-110 PSI. We have speed controllers on the inlet and outlet of the cylinder so we can control how fast the cylinder moves.

Ready to see Crush-a-Can Mk 1. in action? You'll need Windows Media Player 9 or 10 for this.


Scroll down
and stop laughing!

As you can see there were some .... um .... technical problems! Bugger those cans are strong!

Crush-a-Can Mk 2. Was conceived .... and then scrapped. Basically we tried a bigger cylinder and it didn't work either!

Then ............ Crush-a-Can Mk 3. was born!

See what we've done here? Yes ....... you got it! Two cylinders! 

The control system is exactly the same (it worked fine!) You can see the beast to the right with it's safety bar in place. (This also acts as a setting device in that it's also slightly higher than the largest aluminium can I could find).

As with all good engineering design and manufacture we need a highly accurate test piece to measure all the stress and torsion on the machine. 

This is a test piece we had specially machined.

Crush-a-Can Mk 3. is ready to test. Wanna see it?

Hope you had as much fun watching and reading this as we did making it!

2005 GadgetBoy & Turbo-Nutter.com