Vehicle bouncing off the track

[SPP SciO]

Anyone else experiencing difficulty with the vehicle bouncing off the track after jumping a gap? My students spent a lot of time getting a "ski jump" style ramp to work, but catching it on the other side is a challenge, since it will often just bounce right off. The immediate thought is a funnel, but of course, that's not allowed. Any interesting track designs / material choices that you've found reduce the bounce effect? Making the landing ramp really steep would be a possibility, but it's tough to get that 5cm horizontal distance afterwards... Any thoughts are appreciated!

Edit: Also, is there a clear interpretation of "the track may not be enclosed at any point" ? For example - the vehicle jumps off the launch ramp, hits the landing ramp, but there is a ceiling suspended above the landing ramp. The vehicle bounces on the landing ramp, bounces off the ceiling, and back on the landing ramp. Is that ceiling "enclosing" the track? My understanding of words suggests, no, "enclosed" means surrounded on all sides (i.e. a tube). But my understanding of the "spirit of the rules" makes me think this ceiling idea may well be "enclosed." Again, any opinions, expert or not, are welcome!

[retired1]

Good question. for some reason, I thought that it meant that you had to be able to remove the vehicle from any point in the track. I had thought about using the flare end of PVC pipe for the catch end (using a steel ball).

[builder83]

My jump lamds in a general spot about the size of a quarter. I made a 12 cm track wider here, slightly uphill with the sides of the track narrowing (no top as a funnel would have). It still of course has lots of speed and hits a wall before continuing on. Of course took lots of trial and error before working consistantly.

How far were they able to get their ski jump to go?

[vehicleguy]

Hi-
For jumps, foam may be a good idea to soften the landing. It is easy to attach with hot glue and should be able to cushion the ball.
I was confused first about the enclosed track rule. I asked my coach since he was supervising the event and he said his interpretation of the rule was that the ball should easily be able to be removed perpendicular to the direction of the track.

[SPP SciO]

The thinking is now some sort of more flexible, less rigid landing track, so there's some "give" when the ball lands on it. They've been able to get a 30cm jump without any incredible feats of engineering (just orient the jump in the direction of the diagonal of the 60x60 square). I'm almost certain that with a better designed and manufactured device, two jumps of that size would be possible. It's really tough trying to maintain speed while also cushioning the landing of a jump.

[Unome]

The thinking is now some sort of more flexible, less rigid landing track, so there's some "give" when the ball lands on it. They've been able to get a 30cm jump without any incredible feats of engineering (just orient the jump in the direction of the diagonal of the 60x60 square). I'm almost certain that with a better designed and manufactured device, two jumps of that size would be possible. It's really tough trying to maintain speed while also cushioning the landing of a jump.

30 cm horizontally?

[SPP SciO]

The thinking is now some sort of more flexible, less rigid landing track, so there's some "give" when the ball lands on it. They've been able to get a 30cm jump without any incredible feats of engineering (just orient the jump in the direction of the diagonal of the 60x60 square). I'm almost certain that with a better designed and manufactured device, two jumps of that size would be possible. It's really tough trying to maintain speed while also cushioning the landing of a jump.

30 cm horizontally?

Yes. There's almost 30cm of vertical distance between the two ramps also, and the total height from the top of the device to the landing ramp I've mentioned is about 50cm. But if a team were to max out the 80cm height and get a quick "turn-around" I think it's do-able to include two big jumps.

I'll try to remember to post some pictures of what they've built after they compete in Rustin on Jan. 6th. It's definitely still in the prototype phase.

[builder83]

I got 38cm horizontally. Tried 2 jumps of 25 plus and could not get it. Allowing for 25 cm height for a slow track to burn time. Also used diagonal.

[SPP SciO]

Just to follow up - students were not awarded any gap points. The landing track was made of craft foam; sometimes the marble would roll, sometimes it would bounce. Needless to say it bounced at competition, and even still, some of the top scores were double what it would have earned in a best case scenario. Multiple gaps seems to be the winning strategy for sure

[kylg]

So the vehicle can bounce, just not during gaps or else they are void? So this only applies to visible bounces and if the bounce is too small and fast (ie. a 1 mm bounce that happens in a fraction of a second after a gap that nobody would know about unless they look closely at the right moment and are anticipating to find something)