I was curious if i could design a can crusher that i could 3D print. My main concern were the strength.

I have no concerns now :)

This test print is in PLA and works fine. If i print it again in PETG CF  or ASA i know it will be even stronger :)
You do need to put a small dent in one side to get it going, but apart from that it works just like the metal ones on the market.

I have attached some CAD files. If you require a specific file type please let me know and i will see if i can export to that for you.