Hi,
lets get something useful out of your cartons and build up the modular cardboard ball track.
It is mounted on a upright board and suitable for a 40mm table tennis ball.
There are 2 Versions. One for a board thickness of 10mm and one for 16mm.
Easy to print, low material usage (thanks to cardboard), modular and fun fun fun.

BRACKET and RAIL were printed with 1 outer pereimeter, no infill.
Be careful with the first layer. If you have an “elefant foot” you might get assembly issues.
(on Prusa Slicer go to: “Print Settings” → “Advanced” → “Elefant Foot Compensation”)
OUTER and INNER TURN as well as ENDSTOP was printed with 2 perimeters, no infill, 2 solid top layers. Same first layer issues as mentioned above.
Cut the cardboard: The width of 72mm is important so the board fits with the V shape to the brackets. I used two pieces of 48cm length for my 1m long board. But this will vary with your setup. For better V shape bending I took a small cut to the backside of the carton.
The ball stuck at the end of the turn:
The setp to the cardboard might be to high. Fold the V shape of the cardboard and press the cardboard flat at the beginning. I made the experience that a slow speed of the ball gives better turns.
The Rail/Bracket gets loose: Use double sided tape to fix the rail on the board.
The author marked this model as their own original creation.