Problems with car on stop section

[sdupont1]

Car flys off end of track. We built hershey bar car this year and to get a little more COM, I routed out the entire underneath side of the car (funny car style). The car flys, it actually beat my council champs cars track record by a good bit. But I have to figure out a way to stop this thing. I thought of sticking a piece of sandpaper to the bottom or even some foam for surface area. Need something light due to not much weight to play around with. We usually build sleek car WITH BOTTOMS, he wanted something different from his brother. Anybody else run into this problem.

[FatSebastian]

I thought of sticking a piece of sandpaper to the bottom or even some foam for surface area. Need something light due to not much weight to play around with.[...] Anybody else run into this problem.

A smaller piece of sandpaper toward the rear may do the job. Ordinarily you don't want to add abrasive in front of the CoM; as it grabs it causes the car to become unstable on the stop section.

We have also thought about, but never tried, adding a piece of rubber toward the back. I am thinking of a thin slice from adhesive replacement rubber feet or bumpers.

[gpraceman]

We have also thought about, but never tried, adding a piece of rubber toward the back. I am thinking of a thin slice from adhesive replacement rubber feet or bumpers.

Or non-slip strips to put down on flooring or steps. They generally have these at home centers.

[doct1010]

Rubberized tool box liner works as well. Light and thin.

[FatSebastian]

I should add that there are two drawbacks to using sandpaper and/or sandpaper-like material. First, the grit wears away with use and the stopping power thereby reduces over time. Second, there is more of a tendency for gritty materials to damage any non-skid surface in the stop section. (This is why I also suggested trying some kind of rubber-like material.)

FWIW, our experience with non-skid foam material is that it can tear up rather easily, so if you go with Doc's excellent suggestion, you may want to check that the toolbox liner is indeed rubberized and not just thin foam.

[gpraceman]

This is why I also suggested trying some kind of rubber-like material.

I have seen rubberized non-slip strips at home centers, as well. We used some of that on the bottom of our 12-13oz cars at a race with no weight limit.

[sdupont1]

Dad has and I'm going to try one side sticky foam. Its about the thickness I need to fill the void, depending on the weight. Its used for plumbers to wrap pipe for insulation. Will let you know soon how it works.

[Stan Pope]

I often apply a spot of hot glue (1/4 to 1/2" in diameter) to the bottom rear edge of the car directly behind the (lateral) CM. Use care, as always with hot glue, to control the sticky threads that often accompany hot glue.

[habcdb]

Most Lowe's/home depot store sells door trim insulation strips that stick on. You can find it in varying widths (3/4", 1" 1 1/4") and depths (1/8", 1/4" and even 3/8").

[doct1010]

Most Lowe's/home depot store sells door trim insulation strips that stick on. You can find it in varying widths (3/4", 1" 1 1/4") and depths (1/8", 1/4" and even 3/8").

Tried it, adhesive failed after a few contacts with stop section.

[habcdb]

May try spraying it with 3m adhesive spray to stick it on better.

[scoutfrog]

O.K. , Here is my .02 worth. I've got some 1/16 X 2in (?) balsa plywood. It looks like it would be perfect to cover the whole (or hole as it were ) bottom of the car. Just a thought, I got 3 feet of it at Hobby Lobby for $1.47.

[Pinewood Daddy]

Michael's sells 1/64th thick plywood.

[62vetteefp]

We just put a big block of soft foam at the end of the track, also on the sides. Used also used to store the track.

[quadad]

The card stock that FS (and probably others) have suggested here might be a good solution since it is light, VERY cheap, easily applied and a little rougher than the 1/64" plywood (and some of it is presently on clearance at Michael's ).

Other than that, are you not able to just add cushion at the stop section - something to kind of surround the cars, but not cause them to bounce out ?

We had our fasest car this year literally get beat up and lose about 1/2 car length after repeated falls off the side of a about 1' hill type stop section in a race just before our Pack race Next time (if there is one) I will try to get them to do something about that before next years' race.