Hi @pablo, i was a couple of months building this machine because teh same problem, de powerful to shop diferent types of plastic.
Finally i found a 3 HP motor and it work very well.
Hello @pablozalaquett
If the motor was powerful enough to break the blades, it means you don’t need more horse power. The problem might be that you dropped a nut, bolt or any other piece made of a hard material, or the blades in your shredder were not properly aligned before testing it with the motor.
I hope you get to fix your machine soon, let us know if you need any help.