Shredder design not welding required

Hey all,
I have designed and prototyped a modified shredder that doesn’t need welding. Thinking for people like me that can’t weld or is too expensive to outsource. The cost is about the same as instead of the welding, CNC machined plates are required.
See some pictures
I haven’t solved the problem of the sieve, which is another part that gives problems when welding, at least to me, being so thin, so this design doesn’t have a sieve.
If anyone have any designs feel free to share pictures!
If anyone is interested in buying a set of parts, assembled or complete machines, get in touch! 😉

interesting work. I am not sure depending on a CNC (mill, around ~5000 euro) and very precise drilling needed will outweigh the benefits of a usually 50-150 Euro stick welder (needed anyways for works in PP). Also, this requires a pretty good drill press from what I see.

Anyways, I am really happy to see that strong side plates. I am just worried this will skew when adding a 4 Kw motor and also using non-hardened bolts (not that cheap btw.)

could you add the Fusion-360 file on grabcad ? I’d like to check it out 🙂
thanks for sharing,

yeah yeah, just was pointing out a welder cost literally nothing, pretty much needed for all the shredder aftermath 🙂 50 buck for the welder hour, damn, i am doing something wrong, even as IT professional you won’t exceed the 30 – 40 Euro per hour in most free lance jobs around. and yup, that 3mm chassis is quite a joke luckily most of the forces are going into the sideplates/bearings

It all depends on your location and the market then !
I work in a machine shop so have easy/cheap access to CNC mill, whereas the welders would charge £50 /h so for me it makes sense to avoid welding! 🙂
Plus I don’t like the design of the 3mm sideplates, many parts, more sanding, hassle to fit together, not robust enough, asymetric…
good thing these are open source and everyone (that knows) can tweak them to their requirements
see ya!

hey thanks for the file! i gonna check it out next week.
welding vs. drilling/milling, i guess you’re aware that welding makes pretty much all cheaper and easier ? most shops here around take 20 – 30 Euros the hour, only 20% of them have a CNC mill, and they would only get hands dirty with 3 hours min, for that money you can buy the welder twice and it’s rock solid 🙂
you’re sure about 10 mm being enough, even 16 mm twists here on a 2.2Kw module shredding PET …
anyways, nice work !

No problem, I just added the .f3d file to the grabcad model, but with the second one that I’m designing we’d save the 4 square bars, and instead use thicker side plates… always a tradeoff… no welding, but CNC required!

@pporg the countersinking of the side plates is something else that requires a quite powerful machine to do. I wasn’t able with industrial drill press or hobby mill/drill press, had to be done with a mill and coolant. Thicker sideplates can be threaded so no need to countersink.

You also don’t need to buy a CNC mill but just outsource that to a machine shop that can do it for you. It will depend of what you have around you obviously or your skills

I’m not worried about ‘skewing’ (if by that you mean the shredder trying to twist respective to the gearbox when there’s a jam?) as both shredder and gearbox are bolted to a 10 mm steel plate that keeps it rigid.


Sure, here you go: have a look
that’s the one from the pictures, but I’ll be designing another one in the next few weeks, and building a few units to sell, something like this:

That’s interesting and awesome idea, can you also submit the plan for it to see exactly where the modifications are made.