I made a loop tile for Hextraction, the hackable, 3D-printable board game by Zack Freedman.

And the best part is it actually works! I have downloaded and printed a few loop tiles and not one actually worked as a tile, the ball always got stuck or was never going to make it. So, I had a go.

This is a lower board tile for sure and ideally needs a couple of tiles run up, but if the ball hits it fast enough it will go round the loop and carry on out the other side.