Mousetrap Vehicle C

[packer-backer91]

This may be a stupid question, but how are you guys attaching your lever arm to your mousetraps? last year we had a really inelegant and weighty hotglue-string solution, and we can't seem to find dowels that can bridge the two lever arms to superglue without weighing the car down...

Me? I soldered it a metal bar to both traps.

Also, packer, building on the composite thing, would it really be that useful? After all, it can only yield a part of the energy you put into it, so even though it speeds you up on the way back, it also slows you down MORE on the way in, does it not?

I don't know it was just a thought to try, especially with traveling out 3 meters to begin with if you can get some advantage for on the way back it may be worthwhile yet. So what I'm getting at is wouldn’t be ok to be a little slow for 30% of total distance to get some speed boost for the remaining 70% of run? In the long run it may not be worth it but I just wanted to add a point to be thrown around with to see if anyone finds it worthwhile. Also besides this idea, I mentioned much earlier the compound lever arm that was best demonstrated by Solon is also a thing to seriously consider too.

[winneratlife]

This may be a stupid question, but how are you guys attaching your lever arm to your mousetraps? last year we had a really inelegant and weighty hotglue-string solution, and we can't seem to find dowels that can bridge the two lever arms to superglue without weighing the car down...

Me? I soldered it a metal bar to both traps.

Also, packer, building on the composite thing, would it really be that useful? After all, it can only yield a part of the energy you put into it, so even though it speeds you up on the way back, it also slows you down MORE on the way in, does it not?

I don't know it was just a thought to try, especially with traveling out 3 meters to begin with if you can get some advantage for on the way back it may be worthwhile yet. So what I'm getting at is wouldn’t be ok to be a little slow for 30% of total distance to get some speed boost for the remaining 70% of run? In the long run it may not be worth it but I just wanted to add a point to be thrown around with to see if anyone finds it worthwhile. Also besides this idea, I mentioned much earlier the compound lever arm that was best demonstrated by Solon is also a thing to seriously consider too.

Can you explain the compound lever arm?

Also, I think I got a use for the spring. The trick is to have the spring get caught in a wire loop on the car to stop it from spinning, which would then wind it up. What you could do is use a wedge axle of some sort so that as the car goes forward, the spring turns with the axle (no force) and goes sideways until it hits the loop at around 2m. Then, it slows the car down as well as builds force, then when the mousetrap reverses, it would give a bit of extra force to the direction change. Seems theoretically sound, but probably tough to make well.

[Paradox21]

You should be able to regain energy on a turnaround with any standard pin design. Once the string flips around the pin and starts to try to pull the vehicle back, the inertia pulling the vehicle will wrap the line further around the axle, and is re-used on the trek back in. There is no need to add another spring to collect energy you can just re-store (some of) the energy in your mousetrap.

[winneratlife]

You should be able to regain energy on a turnaround with any standard pin design. Once the string flips around the pin and starts to try to pull the vehicle back, the inertia pulling the vehicle will wrap the line further around the axle, and is re-used on the trek back in. There is no need to add another spring to collect energy you can just re-store (some of) the energy in your mousetrap.

We recognize that. The spring is just something extra I'd like to try.

[franklinknights]

how r u making a brakeing system for the mousetrap to come back and stop at the line? i know u can hav string but that has recoil in my mousetrap and that moves it by 5 inches

[ichaelm]

Take a look at this.

[packer-backer91]

Take a look at this.

I'm not too sure one the idea of having using string as a brake especially for this event. String never will spool exactly as you want it to, even if you have threads to guide the string as it transitions from on axel to the next there in a large uncertainty if that will happen exactly the same each run thus distances may be different from run to run. This does make for a simple to make and ok brake, but from my opinion using the wing nut idea which produces better/more consistent results. That’s not to say that the string idea is terrible, if you can make it perform well than go with it. The wing nut design has one flaw that being you have to start with the brake to be locked or almost locked to make the brake work right.

[ichaelm]

Take a look at this.

I'm not too sure one the idea of having using string as a brake especially for this event. String never will spool exactly as you want it to, even if you have threads to guide the string as it transitions from on axel to the next there in a large uncertainty if that will happen exactly the same each run thus distances may be different from run to run. This does make for a simple to make and ok brake, but from my opinion using the wing nut idea which produces better/more consistent results. That’s not to say that the string idea is terrible, if you can make it perform well than go with it. The wing nut design has one flaw that being you have to start with the brake to be locked or almost locked to make the brake work right.

I agree; I have always used something like a wingnut for events like this. But I thought I would link to a page with several options.

[masterhat]

Take a look at this.

I'm not too sure one the idea of having using string as a brake especially for this event. String never will spool exactly as you want it to, even if you have threads to guide the string as it transitions from on axel to the next there in a large uncertainty if that will happen exactly the same each run thus distances may be different from run to run. This does make for a simple to make and ok brake, but from my opinion using the wing nut idea which produces better/more consistent results. That’s not to say that the string idea is terrible, if you can make it perform well than go with it. The wing nut design has one flaw that being you have to start with the brake to be locked or almost locked to make the brake work right.

Actually, with this year's rules, the wing nut design does not need to start with the brake close to the lock. It should actually be 4m worth of threads away at the start of the run.

[franklinknights]

okay, alright. its like scrambler's braking system design from few years. thanks