Mousetrap Vehicle C

[illusionist]

Thanks, I like the coin idea. I'll try that out. So most likely they would be placed above/near each wheel?

[Paradox21]

I actually made a similar system at nationals 2 years ago for Electric Vehicle. I put spare change on the chassis directly over one wheel to straighten out the path of the vehicle. It actually worked pretty nicely considering how impromptu it was.

[illusionist]

After a few mathematical calculations, some estimation + a good dose of good luck, I've successfully and accurately run my vehicle. The vehicle was surprisingly accurate on its first run! Calculating before hand saved me a lot of time. It is right on top of the line when stopping, although it has to be tweaked a little, and needs to run much faster.

[bwy]

What kinds of times/scores are you guys getting?
I have a 9.2 second car that weighs 140 grams and pushes the cup to within 5 cm of the 3 m line (I haven't really looked at the -4m distance score yet since that's more of a problem)

[illusionist]

I'm getting a horrible 28 seconds for the combined run.

[austinfhs]

What kinds of times/scores are you guys getting?
I have a 9.2 second car that weighs 140 grams and pushes the cup to within 5 cm of the 3 m line (I haven't really looked at the -4m distance score yet since that's more of a problem)

How did you get it to only 140 grams? I'm looking at 370ish grams on my vehicle, although I'm around a 10 second run. I'm thinking about dropping my weight so that I can make my acceleration more rapidly. I have a design that should get around 200 grams, but 140 is pretty impressive, haha.

I'm getting a horrible 28 seconds for the combined run.

Have you tried dropping the weight, using a thinner drive axle, or better traction? That should be the best way to increase your speed. As stated in the wiki, and earlier in this thread, if you make the mousetrap arm bar (the one that pulls the string) shorter, you will have greater power, just less string to pull with.

[Vizard007]

What kinds of times/scores are you guys getting?
I have a 9.2 second car that weighs 140 grams and pushes the cup to within 5 cm of the 3 m line (I haven't really looked at the -4m distance score yet since that's more of a problem)

How did you get it to only 140 grams? I'm looking at 370ish grams on my vehicle, although I'm around a 10 second run. I'm thinking about dropping my weight so that I can make my acceleration more rapidly. I have a design that should get around 200 grams, but 140 is pretty impressive, haha.

I'm getting a horrible 28 seconds for the combined run.

Have you tried dropping the weight, using a thinner drive axle, or better traction? That should be the best way to increase your speed. As stated in the wiki, and earlier in this thread, if you make the mousetrap arm bar (the one that pulls the string) shorter, you will have greater power, just less string to pull with.

He probably got that score because he's probably using Balsa wood. As for the "horrible" 28 seconds, is that with the cup reaching the 3M line? Also, can someone explain to me why a thinner drive axle increases speed? Thanks.

[Kokonilly]

I just have a couple questions. (Our vehicle's mostly built.)
1. Are CDs the best wheels, or would it be okay if we used tiny Lego wheels? (These things are really small. I don't have any with me right now, but they're about an inch in diameter.) Would that hurt our performance?
2. Is the best braking method the wingnut-threaded rod method? We're trying to pick one, and that seems to be the braking method of champions.

[winneratlife]

I just have a couple questions. (Our vehicle's mostly built.)
1. Are CDs the best wheels, or would it be okay if we used tiny Lego wheels? (These things are really small. I don't have any with me right now, but they're about an inch in diameter.) Would that hurt our performance?
2. Is the best braking method the wingnut-threaded rod method? We're trying to pick one, and that seems to be the braking method of champions.

Uh, lego wheels would destroy your performance. If you have a 1/8 in axle in diameter (which isn't that easy to find in the first place), your axle:wheel ratio is 1;8. Hence, to travel 10m, you would need 1.25m of windup string. That's not gonna fit...

What's wingnut thread?

I'm getting a horrible 28 seconds for the combined run.

Have you tried dropping the weight, using a thinner drive axle, or better traction? That should be the best way to increase your speed. As stated in the wiki, and earlier in this thread, if you make the mousetrap arm bar (the one that pulls the string) shorter, you will have greater power, just less string to pull with.

Instead of having to redo the vehicle by having to shorten the bar (which can be rather tough, depending on how you designed the vehicle), you could instead make the axle thicker, raising your axle:wheel ratio, also giving more power.

[Kokonilly]

I just have a couple questions. (Our vehicle's mostly built.)
1. Are CDs the best wheels, or would it be okay if we used tiny Lego wheels? (These things are really small. I don't have any with me right now, but they're about an inch in diameter.) Would that hurt our performance?
2. Is the best braking method the wingnut-threaded rod method? We're trying to pick one, and that seems to be the braking method of champions.

Uh, lego wheels would destroy your performance. If you have a 1/8 in axle in diameter (which isn't that easy to find in the first place), your axle:wheel ratio is 1;8. Hence, to travel 10m, you would need 1.25m of windup string. That's not gonna fit...

What's wingnut thread?

Okay, I was just wondering.
A wingnut-threaded rod system would be a lot like this.