I needed a cup holder for my tractor... so I made a cup holder. 

 It can hold cans, cups, or pretty much anything up to 42oz travel mugs.

Uses 7 10x25x2 rectangular magnets. Although they are a press fit, it's best to hold them in with super glue. 

Print right side up with tree supports on bed only. They peel off very easy and leave a pretty decent finish.