Theme Park Discussion / Coaster Model

The ball should only touch the track in two positions. If the third (middle) piece is too high you ball will jump out of the track and you will have a really hard time to find out where to fix the problem.

A half tube is a lot easier and if your ball jumps out you can still add tunnels.

^ Not correcting you, Magnus, but if the ball is jumping out of a half-pipe, either they need to recalculate the hill or tweak the track in order to smooth it out in case there is a bump.

In any case, FM, if your coaster's hills' heights look similar to that drawing, you may very well need to apply WD-40 or some friction decreasing substance in order to clear those hills. Even if you have done the height calculations, your overall circuit may very well fail due to an unknown in the coefficient of friction of the material you are using. I forget what the coefficient of 1/4" clear tubing is (something like mu=.3), but you really need to chose your substances wisely or else your track may fail in a real situation contrary to what your calculations may say.

Oh, and one more thing; if you need your 'car' to slow down a bit while going over a hill (even after modifications), use sandpaper to rough the track in order to get a hint more friction to slow the 'car' down a bit more. And remember to sand a small amount each time in order to not screw everything up.

^ Not correcting you, Magnus, but if the ball is jumping out of a half-pipe, either they need to recalculate the hill or tweak the track in order to smooth it out in case there is a bump.

Sure, but making tunnels is a lot easier.
And that basically is the concept of engineering: Make the solution as easy as possible.

You should throw an inversion in there. It will score big with the non coaster enthusiasts. Maybe make that large hill into a zero-g roll if you have enough speed, or just a simple loop.