It's Alive!!

A project log for Compost Shredder Upgrade

Motorizing and increasing the capacity of a 3D-printed compost shredder

Will F.Will F. 11/02/2015 at 02:020 Comments

Well, I sprinted through the week and got the shredder working!

Found the master link I needed to close the chain.

split the chain to the length I needed, and hooked it up to the sprockets.

I'm very pleased that it fits nicely over a bucket. I don't have to lug it out to the bin any more!

Everything plugs in and is running smoothly with no load. Of course, it has to be tested properly.

I went full-force with all tests and used large carrots. they are the toughest pieces of food that I know the 3D-printed teeth can handle. that meant that any issues would be due to the upgrades.

The first test was a complete failure. As I suspected, the hose clamps did nothing to restrain the tremendous torque this motor is capable of putting out. The chain was also a bit too loose and liked to skip teeth.

Back to the drawing board. First I increased the size of the motor mounting plane

The new mounts are also made from scrap wood. I found a 2 1/8" hole saw fits the motor perfectly. The mount is 3"x3 1/2", and the hole is 1" up from the bottom and centered horizontally.

At this point I was wishing I had a drill press to get the hole to be perfectly straight, but this turned out to have a slight benefit. the small amount of skew between the two mounts jams the motor in place with a lot of force. I was glad of this since the hole was not in itself a secure press fit.

Finally I located the motor in place and secured the mounts to the base with screws. I cut the corners off to clear the hopper.

Also made a (somewhat halfhearted) front plate to make use of the mounting screws that came with the motor. it does its job!

and bam! she chews up carrots without complaint.

Further updates will include some field use notes and probably some small-scale tweaks to the chain alignment to get rid of that crunching noise in the video. I'm very excited to have this working as intended, and can't wait to get back to composting on my regular schedule.

Thank you for your interest!