I have 2 can crushers, one in my garage and the other in the kitchen of my house. Both are mounted into studs.
On your 5er, if you can't mount it to the frame, I wouldn't mount it anywhere. If you try to mount it anywhere, you are running the risk of ripping some holes in your wall when the screws pull out.
Maybe you could mount the crusher on a separate board. Then simply lay the board on a picnic table and with a C-clamp or a wratchet type carpenters clamp, clamp the board to a picnic table on the top (laying flat). Nothing says the can has to be upright when you crush it. Lay it on it's side. By clamping the board to the table, the crusher won't slide around on you when you pull the lever. It just an idea! Good luck!
