Minimum torque required for shredder

Hello everyone, I accidentally found this precious plastic project and suddenly Dave Hakkens become my idol lol 😛
I was going to build the shredder but a 2kw single phase motor is hard to get by not to mention the price of it in my country.
So here I ask for help from anyone, if possible, try to get the minimum torque required when the shredder is shredding some plastic?
From then I can make the calculation backward and find a more easily available motor in my place, perhaps with lower power but higher reduction ratio to achieve the same torque.
Any help is appreciated.

I found that torque(N.m)=power(w)/angular velocity(rad/sec),according to Dave´s recommendatios if you use a 70rpm-2kw motor

That means that you could have the same torque with different specifications for example if you use 3,7kw and 130rpm motor.

Im not completely sure but tomorrow I’m gonna search the motor in my city (Medellin-Colombia). If I know something I will tell you

This is what I want to know too.


I don`t know much about mechanics but what if, after you build the shredder blades and put them together, you use a torque wrench to determine the actual minimum, after that you get your self a lower torque motor according to your readings.

Hi segundaoportunidad, that’s what I calculated as well. But I wish to know the actual minimum torque. Some one who already build the shredder can kindly measure it with a torque wrench, please?