Calculation and formula of horse power of shredder

@flo-2, @ashrak, mine has 254 Nm and the weakest point is the coupling with the motor axle. This linkage consists of two M8 bolts that go through the shredder axle.
These bolts got shear cut twice while shredding a neck of a 5L water canister made of PET😞
BUT it is good enough for shredding all the plastic we have.

So, the questions should be, how much torque do you need?

I acctually got that question from the guys in R&D on Optinova when I asked for a motor…

Yes @ashrak ! Mine has got ~280 Nm and that’s enough for most things. Just some really thick plates (4mm+) or bricks out of solid PP were able to stop my shredder But that happens faster than you would imagine! 3 or 4 smaller pieces of a flowerpot flat ontop of eachother and it gets stuck 😀

@pujiwara @jairlicea @pantheonengineeringdesigns
Hi all!
First I moved the topic to the precious plastic forum, where it belongs 😉

Second, It’s not only the HP or kW that matters. The interesting unit for shredding is torque which is given in Nm (Newtonmeters). It is a combination of power and speed.

If you use a 3 HP motor (2.2kW) with a reducer 1:25, you have the same torque as with a 1.5 HP Motor (1.1kW) with a reducer 1:50. You are turning only half as fast, however you have the same torque, the same “strength”. So theoretically, a 100W motor would be sufficient with the suiting reducer… So yes, as @pantheonengineeringdesigns said, the hard part is finding the right combination, giving you enough torque, because a 3HP motor with a 1:5 reducer won’t shred good.
I hope that helps 🙂

I’m curious how you came to this conclusion. I’ve seen some of the other lines and they say you can use as low as 1/2 hp. The one Dave uses is a 2 hp motor.

I think the hardest problem is finding a motor/reducer combination.