3D-Printed Shredder Eats Lettuce For Breakfast

Shredding things isn’t just good for efficiently and securely disposing of them. It’s also very fun, as well. [Joonas] of [Let’s Print] didn’t have a shredder, so set about 3D printing one of their very own.

The design apes that of the big metal trash shredders you’ve probably seen in videos all over the internet. They use a pair of counter-rotating drums with big teeth. As the drums turn, the teeth grab and pull objects into the gap between the drums, where they are duly torn apart into smaller pieces.

In this design, plastic drums are pressed into service as [Joonas] does not have a metal 3D printer. A brushed DC motor is used to drive the shredder. A large multi-stage gearbox is used to step down the motor’s output and provide plenty of torque to do the job.

The shredder gets tested with plenty of amusing garbage. Everything from old vegetables, to paper, and rock-hard old cheeseburgers are put through the machine. It does an able job in all cases, though obviously the plastic drums can’t handle the same kind of jobs as a proper metal shredder. Harder plastics and aluminium cans stall out the shredder, though. The gearbox also tends to strip gears on the tougher stuff. The basic theory is sound, but some upgrades could really make this thing shine.

Is it a device that will see a lot of practical use? Perhaps not. Is it a fun device that would be the star of your next hackerspace Show and Tell? Absolutely. Plus it might be a great way to get rid of lots of those unfinished projects that always clog up your storage areas, too! Video after the break.

15 thoughts on “3D-Printed Shredder Eats Lettuce For Breakfast

  1. At least in Germany, such a working and cheap tool is the nightmare of every waste management company.

    We pay garbage mostly by volume. You get a certain sized waste container, pay for the size and are allowed to fill it. Compressing your waste is illegal by your local waste statute. You can buy waste compactors [1], if you are caught you might be fined and/or container is not emptied.

    So shredding it would technically no compressing…

    1: https://www.test.de/Muellpressen-In-die-Tonne-gepresst-4431117-0/

  2. Quite entertaining and interesting at the same time.
    Isn’t that how Maccy D’s cheeseburgers actually come “fresh” from the restaurant? That thing looked like it was fossilized when he tapped it on the counter! XD
    The gears were ABS which he says gives no mechanical advantage over PLA, but I thought that was the point of printing with ABS – the objects are stronger, which would make sense for gears at least, especially when they are subjected to prolonged use.
    The PLA “blades” certainly took a pounding. That was pretty impressive. I would guess that they are probably printed with quite a high infill percentage.
    One suggestion though, and that is some kind of screen around the top to stop the stuff you’re shredding getting sprayed all over your workshop, especially if it’s rotten food!

    1. PLA is quite good stuff for some gears. Print them with many perimeters and you’re golden. Ofc it’s not steel but if you use the normal PLA (not matte, not filled) you can get super sturdy parts from it.

      For gears it’s about being flexible enough on the inside but hard enough on the surface to be wear resistant. PLA does that job better than many other plastics in 3D printing, especiall PETG and ABS/ASA.

      1. PLA is also self-lubricating in a very real sense: On a microscale, if there’s a high point creating friction, it will heat and melt, removing itself. The end result is a no friction-generating rough spots. Kind of Darwinian of it.

  3. Lol, just skip 15 or 30s. What’s the big deal here?
    He gets some money back from the PCB company, and we can skip it with just 2 or 3 double-taps on mobile or a single click on desktop.

    Don’t be a snowflake, summer’s coming!

  4. There is a quite big fundamental flaw with this design.
    In a real shredder the “washers” in between the “shredder disks” have a significant smaller diameter, and the edges between the shredder disk overlap much more and act like scissors. Because of this flawed design I’m surprised that it works at all. So apparently the creator is not that far off anyway

  5. I’ve been pondering a yard waste shredder. According to most reports, the chipper/shredders that fit within most homeowner’s budgets are not worth the time or money, and renting an adequate chipper is easily a similar cost on a yearly or biannual basis.

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