Mousetrap Vehicle C

[winneratlife]

lmao, I'm sorry. I didn't mean to freak on you... The end of the third nine weeks was today, I have been so stressed to get all of my work done. As for Physics, lol.... I wish you could be in APC Physics with me, lol... If you saw me in that class, you wouldn't believe that I was SciO worthy, hahaha...

I found out today our team placed 8th at regionals, thought that was pretty cool... As for my car, if it is flawed, then it reflects its creator, lol... I'll never reach perfection, but I;ll try my best =) Again, sorry for being so defensive...

Lmao no problem...
We all have those moments
(I haven't even taken physics 1 I'm just good at mechanics)

Anyways, moving on to the car. I personally think that the pin-axle design (number 3 on the wiki) is the optimal design, as I've never seen an actually competitive car not running that design. However, Troy HS claimed to me that they have a prototype of a double mousetrap (in opposite directions) design that works (I'm assuming that they use a ratchet-pawl and wind both axles before hand, but I've never seen it), but pin-axle is still better, as that is what they used in competition, over their prototype. When using that design (with a long bar) you don't even need vinyl records, btw...

Are you going to states? Or is your season over?

[Paradox21]

Has anyone actually tried making a ratchet and pawl system? To me it seems like it wouldn't work. If your rachet is your axle and your pawl is whatever you are winding your string around. You would design it to allow the axle to rotate clockwise and have the ratchet slide under the pawl. In that way you would certainly keep the 2nd mousetrap tight on the run out. But upon the triggering of your 2nd mousetrap, I don't think it would move anywhere because you would rotate the pawl counter clockwise. Rotating the axle (rachet) clockwise or the part holding your wrapped string (pawl) counter-clockwise would make it slip over the rachet causing the mousetrap to unwind without turning the axle.

A simple rachet system doesn't make a whole lot of sense in this application. However, if you wanted 1 mousetrap on each axle you might have success with a threaded rod. Have some type of nut slide towards the wrappings for that axle and get it to time perfectly to connect your wrappings to the axle right when you trigger the mousetrap. I think that system could have the potential to be very efficient but would be very complicated and so much could go wrong.

Personally, I keep both mousetraps on 1 axle and use a pin and things go smoothly.

[winneratlife]

Personally, I keep both mousetraps on 1 axle and use a pin and things go smoothly.

That's what I do too... It works great...

On the other hand, I'm just wondering how a prototype of the other way would work.

[packer-backer91]

does anyone know who the top 6 teams where at Michigan's Region 12 in this event are? I attended but did not stay for the results.

[x16VOLTx]

Are you going to states? Or is your season over?

My season is over, we were two places away from making it to states. I'm kind of glad we didn't make it though, I think states for SciO is the same day as states for Envirothon. I hate to admit it, but I like Envirothon more.

Also, I only stayed to watch one other car make its run, and it used 2 mousetraps, one on each axel, and it reached the mark and returned. It's error distance was more than mine though, cause he didn't adjust his strings before the run I like did. Me and my tech teacher put notches in the end of the rods we attached the strings to; this basically made it calibrate-able.

One thing I noticed is that a great number of teams made their front set of wheels smaller than the back set. This would only make it harder to bring the car back would it not? You would need more power to bring it back, because the wheels have a smaller circumference... Ah well, all is said and done now.

[Gooblah]

Well, my district beasted at Regionals, taking 5/8 spots to go onto states; our two middle schools and three high schools. Even made the front page of the local big city's newspaper ahahahah. Cool stuff. Anyways, we were unable to participate in Mousetrap this year at Regionals because the car basically died before competition (I think a mousetrap or a rod broke on the night before, with no time to fix it, so the car didn't go in reverse). I got drafted since our genius freshman (not being sarcastic)'s partner couldn't make any meetings so he was working on it by himself.

In terms of design, looking at the wiki, the original plan strongly resembled Plan 1 (one mousetrap winds up the other); there was a brake I believe, since I saw their tests a week before Regionals and they hit 7.5m; but, when they came back, they only went about two meters before failing. However, it seems to me that this Plan was kind of inefficient, considering that it's a) hard to get the winding right, b) hard to coordinate the mousetrap actions, and c) kind of a pain to fix.

So, I looked at Plans 2 and 3, then scoured the internet and this thread. Plan 3 seems to be the most popular and is probably a good starting point. We have a month before states, so we have enough time to build and test if get on our design right away. I need some clarification though: Basically, a string is tied to the back axle (counter-clockwise), then around a pin, then around the front axle (clockwise), and finally connected to the rod which is hooked to both axles? or something?

I'm simply having trouble visualizing this set up...where is this pin? I've done simple mousetrap vehicles (forward only), so I understand the basic mechanism, but....

Thanks for any help.

[robotman]

So, I looked at Plans 2 and 3, then scoured the internet and this thread. Plan 3 seems to be the most popular and is probably a good starting point. We have a month before states, so we have enough time to build and test if get on our design right away. I need some clarification though: Basically, a string is tied to the back axle (counter-clockwise), then around a pin, then around the front axle (clockwise), and finally connected to the rod which is hooked to both axles? or something?

I'm simply having trouble visualizing this set up...where is this pin? I've done simple mousetrap vehicles (forward only), so I understand the basic mechanism, but....

Thanks for any help.

for the third method all motion comes from one axle

your axle and string would look like this
---------------------||
********************-||
---------------------||

where * is string and -|| is the pin

you would wrap the string one direction on the axle than loop it around the pin and continue wrapping
there is a video that should be in the Image gallery

[Gooblah]

for the third method all motion comes from one axle

your axle and string would look like this
---------------------||
********************-||
---------------------||

where * is string and -|| is the pin

you would wrap the string one direction on the axle than loop it around the pin and continue wrapping
there is a video that should be in the Image gallery

Ohhhhhh!

Thanks so much, that makes a lot more sense, alright.

Finally, did anyone use construction materials besides balsa? From prior experience, it's a pain to get parallel axles...I was considering hot-gluing some lego pieces down to ensure the axles were parallel, and then swiss-cheesing the mousetraps....

[packer-backer91]

Ohhhhhh!

Thanks so much, that makes a lot more sense, alright.

Finally, did anyone use construction materials besides balsa? From prior experience, it's a pain to get parallel axles...I was considering hot-gluing some lego pieces down to ensure the axles were parallel, and then swiss-cheesing the mousetraps....

if you mean cutting a bunch of holes in the muse trap by "Swiss-cheesing" I don’t think that is legal. Holes may be put in to secure the traps to the frame, other than those holes it intended that you can’t use more holes to reduce weight in the mousetraps base.

[Gooblah]

Ohhhhhh!

Thanks so much, that makes a lot more sense, alright.

Finally, did anyone use construction materials besides balsa? From prior experience, it's a pain to get parallel axles...I was considering hot-gluing some lego pieces down to ensure the axles were parallel, and then swiss-cheesing the mousetraps....

if you mean cutting a bunch of holes in the muse trap by "Swiss-cheesing" I don’t think that is legal. Holes may be put in to secure the traps to the frame, other than those holes it intended that you can’t use more holes to reduce weight in the mousetraps base.

Darn. And swiss-cheesing the balsa would probably tear the vehicle apart. Hmm, looks like I'll have to embark on a minimalist design, eh?