Foam Shredder

Set up and tested 1 1/2" pvc to fill the gap where the edges of the nail laden pvc don't meet. Motor installed, top deflector installed, ready to go.

I’ve got the foam shredder prototype working. The roller center is a solid stainless conveyor roller from a fresh produce processing plant.  My brother was going to add short spikes to it for my shredder drum but he ran out of time about five spikes into the project.  The pulley is from a box of stuff we collected somewhere and the key to hold the pulley on came out of a drawer.  The motor goes on the cement mixer and the belt was hanging on the shop wall.  The gray is aged black pvc pipe left over from some other project. I’ve drilled a grid of holes 1/2″ apart and stuffed the holes with 3/4″ roofing nails that were a box that went from my dad’s estate to Dan and then to us.

I started with just the pvc filled with roofing nails.  I was going to add a central shaft and pour it full of concrete but Dan sent the roller with bearings attached.  It seemed smarter to split the pvc and slide it over the roller rather than try and come up with a shaft and bearings.  There’s a trick to holding all the nails in place as you work.  If you need to know, ask me.

I probably don’t need the pvc filler in the blank spot, but I’d rather do what I can to ensure consistency in the particle size.  When I tested it without the pvc and while rotating the wheel by hand I ended up with occasional bigger chunks when the foam was caught by the blank space.

The last picture is the shredder ready to go.  The base/box is one of a pair built to act as supports for Dan’s lathe.  The bungy cords hold the door on to keep the shredded foam in.  The deflector is a cut down plastic waste basket that had multiple splits at the top.  I used a box knife on it to reshape it for this task.  It’s held down by gravity.  If that doesn’t work, I’ll figure out how to stabilize it.

To dispense the foam I’m going to flop the box onto its left side, undo the bungies and shovel the shredded foam into the mixer or storage container.

So far I have exactly zero dollars and a couple hours in this project. I think that’s pretty good for the result.

I’ve got two big pieces of  foam ready to grind.  Once it cools a little off a little bit outside I’ll shred them.  I’ll measure the size of the pieces and time how long it takes to shred them.  If I can get some foam shredded today Wadly and I can mix up a batch of eps-crete tomorrow.