I ‘d like to replace one of the 3 Interchangeable Blades.  Can I still purchase only one blade?

Can I buy individual parts such as screws, safety guards (including the parts for previous model of BENRINER)?

I just tried BENRINER, but it doesn’t cut.

Vegetable gets stuck and doesn’t move forward.

BENRINER is made of plastic.   Is the plastic safe for vegetable?  Any problem?