Bowling Rev trainer

I decided to make a simple yet effective rev trainer for bowling (since rev trainers online are like $100+)

There are 3 versions (different sizes) but they all use the same roller bearings https://www.amazon.se/dp/B09B39YX7Q?ref=ppx_yo2ov_dt_b_fed_asin_title

They also use m5 threaded heat inserts to mount the bearings, keep in mind that you need to use 1/4" spacers to tilt the bearings so the ball will stay in place (I'll make a version later that doesn't need this)

You could just use a MDF board instead but hey, why have a printer if you ain't gonna use it.