Comment on the schreddertest

Hi Kees,

I miss the counterknives? In our little schredder from Marcus, it will only shred hard plastics without the counterknives. I think your mushroom cannister is too soft:-)

Looks nice though! Succes

Hi Boy,
Other knifes with a bigger overlap are in production, bigger knife smaller spacer……
That should make a difference we hope.
Do you think it’s not possible without counterknifes?

I think I see the function of the counterknifes, but I’m concerned of blockages by the sieve .
You will need the sieve for the counterknifes to work and pick up the bigger parts again.

I would like to put the sieve 200 mm lower ( on a slope and vibrating would be my goal) , and feed the bigger parts again.

All thoughts and input welcome 🙂 !!!

regards kees

dI’ll send you somewhere this week samples with data as how many turnes needed in single, double and triple batches etc. So you can figure out yourself.

This was a little premature.sorry. A lot of things happened the past few weeks. I’ll try to shred some batches this thursday and send them the next friday. Saying this, I’ll have to find out your workshop adress:-)

Btw. On my ipad and iphone, I can’t upload an attachment because it is greyed out. I have to put the images somewhere on the internet at first.

Hi Dave,

Normally, after submitting, the original poster has the ability to alter the post by a “edit” quotation. I don’t see it on this forum.

Everybody like’s to shred and destroy things. If our guests see the shredder, it will be turned almost automatically. Bottles have to be cut into smaller chunks, say approx 5-10 cm unfortunately. Marcus just published a bigger one for ” industrial” use, costs €600 though. The only way to accomplish that a fast way, is a guillotine or a A4 paper cutter but that is too dangerous. I’m still working at the idea.

The shreds are to big in the first batch imho. Don’t think that will be a problem for the injector. But the shred size was the reason I use a 30 mm wood drill for the extruder. Hoping it will be big enough to catch the bits and peaces and is willing to transport the stuff. If you put a bottle heads down, it will catch it. But without pushing it in after the first 5 bites, it will not work any further. I’ll send you somewhere this week samples with data as how many turnes needed in single, double and triple batches etc. So you can figure out yourself.

We just got the new PIDS, the extruder hotend plate is soldered in place, hot end with tc, heaters with tc are assembled and turning. Robert, our lasercutting specialist at the KF, made a beautyfull housing for the electronics. I tried to figure out a modular idea, so we can use it for all the machines which need heating and with or without motor handling. Therefore all the induvidual heaters will have a Euro mains cable, all the tc’s a bananaplug. On the box there will be 4 wallsockets and female banana sockets, also for the 24V motors. Everything is marked with laser engravings. This way, you still have to know what you’re doing, but it will be plug and play without a screwdriver or wrench.
How is that for modulair thinking?-)

You should be able to delete does yourself…weird. I’ll look into it

Thanks for sharing the outcome, nice solution!
How is the shredder performing, you like it? Can you crush…let’s say a whole plastic bottle with it? -or is it mainly used for 3D printer waste? And what is the size of the outcome? We saw some youtube videos about it, but no one really showed the outcome of the granulate.


please remove first of two posts:-)

Is there a way to edit your own posts?


Marcus wants a maximum of 250Nm on his mini shredder. His suggestion is to make use of 3 plates, two different materials. Mount the plates With the handle in between under the M14 Nut with a torque of 250Nm. If it stucks, or you give too much torque , it will slip accordingly.

This works, it has a nasty habit though, when it slips. You could get the handle with high speed under your chin or from the guy or gal next to you:-D

My solution is the next. Look at the green insert. It will lock the nut, if put in the hollow end, because of the sleeve. The nut should not be tightened entirely , turn it until the end and rewind until the nut fits in the hexa diagonal hole. The metal housing will stay put without play. If the torque exceeds its maximum, the insert will break and tightens the nut instead of turning around loosely. You will stop turning the handle around, believe me, but without hurting yourself or someone else. 3D printing a new insert costs you $1 and two hours time. Density between 70-100% PLA gives you a breaking point between 200-250Nm. That is to say, in this configuration.

I’ll publish the CAD (DXF) and part (SolidWorks) drawings soon. Let me know if you want another extension at that time.

Break at torque 200Nm

Breakable parts

Mini Shredder on Bosch/Rexroth alu extrusion

The handle

The sieve!:slight_smile: that’s a troublemaker in this setup. Presuming a low speed setup.

Your other shredder is a highspeed schredder and its abilty to transport the bigger particles depends on that speed. Marcus tried the same principle on his minishredder but that didn’t work out. For him anyway. I tried to find a shredder based on our principle with a sieve but couldn’t find one yet, did you? It seems to be used for heavy duty work mainly, although with very impressive results because of the high torque at low speed . I also havent seen result from these type of shredders that manage to get the shreds as small as your other machine.

If we could find such a setup with a sieve, that would be the place to look.

Our shredder is working now. With a handle for now. I’m designing a 3D printed insert, which will break if the load will be bigger than 250 Nm. This will be used for motor operation too. Another step to fix different measurements of axisdiametres etc if we want to make use of the modulair principle. With the original partdrawings, it will be easy to alter the axisholes to your own needs, or 3D print a new one if broken.

We keep in touch. Photo’s and drawings will follow.