Mousetrap Vehicle C

[thesenotes]

Is anyone having trouble with accurately depositing the cup? In practice, I consistently got the cup to go 30 cm past the cup line, but at MIT, I ended up getting up getting 20 cm behind the cup line, totally screwing up my first run. The car's travel to the cup line seems to be dictated very heavily by the friction the cup has with the floor surface. Is anyone having similar problems and/or are able to overcome this?

[Alex-RCHS]

Is anyone having trouble with accurately depositing the cup? In practice, I consistently got the cup to go 30 cm past the cup line, but at MIT, I ended up getting up getting 20 cm behind the cup line, totally screwing up my first run. The car's travel to the cup line seems to be dictated very heavily by the friction the cup has with the floor surface. Is anyone having similar problems and/or are able to overcome this?

Not me personally. If you are using the most common setup then the number of times the string wraps around the axle should determine how far the car goes, assuming nothing is slipping. Friction will slow the car down, but it should not alter its distance traveled*.

*the only exception to this is if you run out of steam before you make it all the way back to the target point.

[Otkrlj]

Wow, how were you able to get 4 seconds? I'm guessing you used balsa? Was it still accurate at those speeds?

Ya we used balsa. It was not very accurate. The best we got it was 2 cm off

2cm off is actually pretty accurate. In my experience, its not possible to consistently get any more accurate than ~2cm on an average run due to extraneous variables out of your control. If you are consistently getting ~2cm off, start learning how to adjust for the second run and work on lowering that time score.

Well the 2 cm was a pure luck run and only happend once and were trying to get that consistently but at 4 secounds its verry fast so theres a lot of wheelspin

[thesenotes]

Is anyone having trouble with accurately depositing the cup? In practice, I consistently got the cup to go 30 cm past the cup line, but at MIT, I ended up getting up getting 20 cm behind the cup line, totally screwing up my first run. The car's travel to the cup line seems to be dictated very heavily by the friction the cup has with the floor surface. Is anyone having similar problems and/or are able to overcome this?

Not me personally. If you are using the most common setup then the number of times the string wraps around the axle should determine how far the car goes, assuming nothing is slipping. Friction will slow the car down, but it should not alter its distance traveled*.

*the only exception to this is if you run out of steam before you make it all the way back to the target point.

Yes, but on the way to the cup line what happens is the cup's friction causes it to slow down, and this shortens the distance that the car takes to slow down before turning around to the target point. This makes it undershoot a lot for me.

[antoine_ego]

Is anyone having trouble with accurately depositing the cup? In practice, I consistently got the cup to go 30 cm past the cup line, but at MIT, I ended up getting up getting 20 cm behind the cup line, totally screwing up my first run. The car's travel to the cup line seems to be dictated very heavily by the friction the cup has with the floor surface. Is anyone having similar problems and/or are able to overcome this?

Not me personally. If you are using the most common setup then the number of times the string wraps around the axle should determine how far the car goes, assuming nothing is slipping. Friction will slow the car down, but it should not alter its distance traveled*.

*the only exception to this is if you run out of steam before you make it all the way back to the target point.

Yes, but on the way to the cup line what happens is the cup's friction causes it to slow down, and this shortens the distance that the car takes to slow down before turning around to the target point. This makes it undershoot a lot for me.

How light is your vehicle? A super light vehicle might be more affected by the floor.

[PM2017]

Is anyone having trouble with accurately depositing the cup? In practice, I consistently got the cup to go 30 cm past the cup line, but at MIT, I ended up getting up getting 20 cm behind the cup line, totally screwing up my first run. The car's travel to the cup line seems to be dictated very heavily by the friction the cup has with the floor surface. Is anyone having similar problems and/or are able to overcome this?

Not me personally. If you are using the most common setup then the number of times the string wraps around the axle should determine how far the car goes, assuming nothing is slipping. Friction will slow the car down, but it should not alter its distance traveled*.

*the only exception to this is if you run out of steam before you make it all the way back to the target point.

Yes, but on the way to the cup line what happens is the cup's friction causes it to slow down, and this shortens the distance that the car takes to slow down before turning around to the target point. This makes it undershoot a lot for me.

I guess that's why we have the second run...

[Alex-RCHS]

Is anyone having trouble with accurately depositing the cup? In practice, I consistently got the cup to go 30 cm past the cup line, but at MIT, I ended up getting up getting 20 cm behind the cup line, totally screwing up my first run. The car's travel to the cup line seems to be dictated very heavily by the friction the cup has with the floor surface. Is anyone having similar problems and/or are able to overcome this?

Not me personally. If you are using the most common setup then the number of times the string wraps around the axle should determine how far the car goes, assuming nothing is slipping. Friction will slow the car down, but it should not alter its distance traveled*.

*the only exception to this is if you run out of steam before you make it all the way back to the target point.

Yes, but on the way to the cup line what happens is the cup's friction causes it to slow down, and this shortens the distance that the car takes to slow down before turning around to the target point. This makes it undershoot a lot for me.

How are you determining the distance of the reverse? By winding the string around the axle a certain number of times?

[DarthBuilder]

So when your get to the cup distance target it would be 3 meters plus 5 to 7 I believe. So you have to do the math for your rotations as if it were going backwards.

[thesenotes]

Not me personally. If you are using the most common setup then the number of times the string wraps around the axle should determine how far the car goes, assuming nothing is slipping. Friction will slow the car down, but it should not alter its distance traveled*.

*the only exception to this is if you run out of steam before you make it all the way back to the target point.

Yes, but on the way to the cup line what happens is the cup's friction causes it to slow down, and this shortens the distance that the car takes to slow down before turning around to the target point. This makes it undershoot a lot for me.

How light is your vehicle? A super light vehicle might be more affected by the floor.

Its quite heavy, about 490 grams.

[antoine_ego]

Yes, but on the way to the cup line what happens is the cup's friction causes it to slow down, and this shortens the distance that the car takes to slow down before turning around to the target point. This makes it undershoot a lot for me.

How light is your vehicle? A super light vehicle might be more affected by the floor.

Its quite heavy, about 490 grams.

Considering the weight, I doubt that it'd be friction that causes it to slow down. Could it be that you accidentally had a different number of winds? A 490 car shouldn't be amazingly affected by the friction.