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packer-backer91 wrote:How heavy is your vehicle it has to be extremely light correct [under 250 Grams]? But under 10 seconds that is very impressive, that was very surprising to hear that their was a vehicle that is under 10 seconds total.

I'm not sure of the weight - I'll try to get and report later this week. Tried weighing on the scale we use for bridges -it only goes to 200g; it is more than that.....
Thanks. We figured from the start that getting it as fast as possible would be important- especially with the point value of speed doubling at State. Early-on we had the test chassis running one way at 3.5 sec.

Speed capability is primarily a function of what I'll call the basic gearing ratio; wheel diameter/axle diameter; the time over which you put the energy contained in the trap into the vehicle. From there, speed is a combination of low weight (f does = ma....), and low friction. Rotational inertia of the wheels is another significant factor. Those are the major things to play with for speed.

Balsa Man wrote:

packer-backer91 wrote:How heavy is your vehicle it has to be extremely light correct [under 250 Grams]? But under 10 seconds that is very impressive, that was very surprising to hear that their was a vehicle that is under 10 seconds total.

I'm not sure of the weight - I'll try to get and report later this week. Tried weighing on the scale we use for bridges -it only goes to 200g; it is more than that.....
Thanks. We figured from the start that getting it as fast as possible would be important- especially with the point value of speed doubling at State. Early-on we had the test chassis running one way at 3.5 sec.

Speed capability is primarily a function of what I'll call the basic gearing ratio; wheel diameter/axle diameter; the time over which you put the energy contained in the trap into the vehicle. From there, speed is a combination of low weight (f does = ma....), and low friction. Rotational inertia of the wheels is another significant factor. Those are the major things to play with for speed.

Um...and 4x at nats...
I'm still trying to figure out how to get my speed even lower for states... (assuming we make it)
What mousetraps are you using? I get the feeling that stronger mousetraps = faster car (duh, F=ma)

this is a lot of difference between kinds of mousetraps and sometimes between mousetraps of the same brand, the strongest mouse traps I could find are not even sold anymore [they were probably 5 years old, a team member showed them too me] and they had more force than the regular Victor mousetraps that I use have.

packer-backer91 wrote:this is a lot of difference between kinds of mousetraps and sometimes between mousetraps of the same brand, the strongest mouse traps I could find are not even sold anymore [they were probably 5 years old, a team member showed them too me] and they had more force than the regular Victor mousetraps that I use have.

Which would help speed. Which I really need.

But, you do have to make sure that the mousetraps don't break the string. That would be bad.

packer-backer's right - a lot of variability

Tomcat brand seems to be usually a little stronger than Victor

winneratlife wrote:

packer-backer91 wrote:this is a lot of difference between kinds of mousetraps and sometimes between mousetraps of the same brand, the strongest mouse traps I could find are not even sold anymore [they were probably 5 years old, a team member showed them too me] and they had more force than the regular Victor mousetraps that I use have.

Which would help speed. Which I really need.

But, you do have to make sure that the mousetraps don't break the string. That would be bad.

For any science Olympiad event I would never use anything that has a potential to break, the string I use has a really high pound test rating and I know that the mousetraps don’t come close to breaking it. You are right the stronger the spring = stronger the string. It is better to be safe the sorry I know the mouse trap doesn’t have that much pull put use string that you are sure will never break.

What mouse traps have everyone been using [my guess is Victor being the most common]

packer-backer91 wrote:

winneratlife wrote:

packer-backer91 wrote:this is a lot of difference between kinds of mousetraps and sometimes between mousetraps of the same brand, the strongest mouse traps I could find are not even sold anymore [they were probably 5 years old, a team member showed them too me] and they had more force than the regular Victor mousetraps that I use have.

Which would help speed. Which I really need.

But, you do have to make sure that the mousetraps don't break the string. That would be bad.

For any science Olympiad event I would never use anything that has a potential to break, the string I use has a really high pound test rating and I know that the mousetraps don’t come close to breaking it. You are right the stronger the spring = stronger the string. It is better to be safe the sorry I know the mouse trap doesn’t have that much pull put use string that you are sure will never break.

What mouse traps have everyone been using [my guess is Victor being the most common]

Yeah, Victor here...
If Tomcat is stronger, I'll have to try that for states...

Balsa man what is your avg total score, I think I know away to produce great acceleration but, what I am thinking of would not have very good of brakes. I know you said you had trouble stopping yours accurately but how bad are you talking about 10+ cm away? In fact I may try to build a proto type mouse trap vehicle at my school if I can dig up some of the needed material but no way it will be as good as how it looks on paper. I have an idea of how to make the proto type FAST but I know for a fact that it will not be able to stop that well. Also one more question do you rely on the mouse trap to propel your vehicle both ways or do you use the mouse trap to power it one way and use a secondary scores of energy to get it to come back [like a rubber band or spring that is stretched out as the mouse trap goes forward?]

packer-backer91 wrote:Balsa man what is your avg total score, ...I know you said you had trouble stopping yours accurately but how bad are you talking about 10+ cm away? Also one more question do you rely on the mouse trap to propel your vehicle both ways or do you use the mouse trap to power it one way and use a secondary scores of energy to get it to come back [like a rubber band or spring that is stretched out as the mouse trap goes forward?]

Actually, I just said we had to work on distance - a problem with getting all the power available on the return trap to the wheels. At Regionals, it ran out of go a little over a meter short of getting back - not a braking issue. Power is all trap- no secondary source

Balsa Man, what design are you using? (One mousetrap each way or both mousetraps connected with with a rotation in the string around the axle halfway)