Mousetrap Vehicle C

science
Member
Member
Posts: 1
Joined: December 14th, 2009, 4:34 pm
Division: C
State: TX
Has thanked: 0
Been thanked: 0

Re: Mousetrap Vehicle C

Post by science »

anyone know how to make the vehicle go backwards? please??? thanks!
robotman
Admin Emeritus
Admin Emeritus
Posts: 1447
Joined: June 29th, 2008, 7:37 pm
Division: Grad
State: TX
Has thanked: 0
Been thanked: 3 times
Contact:

Re: Mousetrap Vehicle C

Post by robotman »

cypressfalls_Robert wrote:does the type of string used affect the distance the car can travel?
If yes then I would llike to try sewing thread(any stiff threads) fishing line and any other stretchy type of string.
When i did it the string was only really a problem when it was really stretchy such as twine
I found that sewing thread broke fairly easily
I settled on Kevlar string that i got as a sample from a manufacturer
science wrote:anyone know how to make the vehicle go backwards? please??? thanks!
Read the Mousetrap Vehicle Wiki there is a whole section on ways to make it work ;)
Edit the Wiki.
Upload to the Image Gallery
[medals]Get Medals[/medals]
[chat][/chat]
winneratlife
Member
Member
Posts: 335
Joined: December 16th, 2009, 3:52 pm
Division: Grad
State: MI
Has thanked: 0
Been thanked: 0

Re: Mousetrap Vehicle C

Post by winneratlife »

A few questions:

On the wiki, it says to add a bar to the trap. But, isn't that modifying it and thus breaking the rules?
For the third example on the wiki, it says to wind the string x times around the axle to travel x meters. Does this assume that the circumference of the circles is 1 m, or is the ratio of winds to wheel turns not 1 to 1 because of some other factor?
Also, building on the last question, how can one guarantee that the string won't fall off or have a slip thus messing up the distance? Do you just, say, do something like tape the end of the string (obviously not the winding) to the axle or something?
Dark Sabre
Admin Emeritus
Admin Emeritus
Posts: 705
Joined: January 4th, 2004, 5:53 pm
Division: Grad
State: KY
Has thanked: 0
Been thanked: 0
Contact:

Re: Mousetrap Vehicle C

Post by Dark Sabre »

On the wiki, it says to add a bar to the trap. But, isn't that modifying it and thus breaking the rules?
Check out 3.a. in the rules. It tells you there that "unmodified" means that all the original parts have to be there, but that you can add things to it or drill holes.
For the third example on the wiki, it says to wind the string x times around the axle to travel x meters. Does this assume that the circumference of the circles is 1 m, or is the ratio of winds to wheel turns not 1 to 1 because of some other factor?
It should say wind x times to travel y meters. The relation between x and y will depend on the ratio of the axle to wheel diameters. I think I'll work over that page later tonight.
robotman
Admin Emeritus
Admin Emeritus
Posts: 1447
Joined: June 29th, 2008, 7:37 pm
Division: Grad
State: TX
Has thanked: 0
Been thanked: 3 times
Contact:

Re: Mousetrap Vehicle C

Post by robotman »

winneratlife wrote: Also, building on the last question, how can one guarantee that the string won't fall off or have a slip thus messing up the distance? Do you just, say, do something like tape the end of the string (obviously not the winding) to the axle or something?
There a a couple of ways
1. add a pin to the axle either via a spool that is attached to the axle by two nuts --/|==,==|\-- so it would look like that
( |====|=spool -- --= axle /\=nuts ,=pin
2. Glue/tape string to the axle
3.Drill through the axle (not recommended for small axles, actually not really recommended unless you have a lot of patience and drill bits)
Edit the Wiki.
Upload to the Image Gallery
[medals]Get Medals[/medals]
[chat][/chat]
winneratlife
Member
Member
Posts: 335
Joined: December 16th, 2009, 3:52 pm
Division: Grad
State: MI
Has thanked: 0
Been thanked: 0

Re: Mousetrap Vehicle C

Post by winneratlife »

Okay great thanks guys.
Now, the only thing I don't understand is exactly how the car is propelled forward. I kind of get that the spring on the mousetrap turns the string, which turns the axle, which turns the wheels, but then isn't the car just one gigantic wind-up toy?

I'm thinking about something different though. Can you guys give me some feedback?

If one used two mousetraps, and connected one string to one mousetrap to the front axle, and one to the other mousetrap to the back (by taping the ends), and the strings were of identical length, and wound the string on the front axle but not the back, would it work? I mean, by turning the first two wheels, you are turning the second two wheels, essentially winding the second string, which will unwind when the other string stops unwinding for the return trip. The only problem I can think of is the loose string, but I think that can be fixed. However, I fail to see how it is superior to the other cars.
robotman
Admin Emeritus
Admin Emeritus
Posts: 1447
Joined: June 29th, 2008, 7:37 pm
Division: Grad
State: TX
Has thanked: 0
Been thanked: 3 times
Contact:

Re: Mousetrap Vehicle C

Post by robotman »

That is one way to do it and it does work
You may want to make it a pin attachment so that after it has done its job (taking it out ) it will fall off and not cause an endless cycle of out and back
Edit the Wiki.
Upload to the Image Gallery
[medals]Get Medals[/medals]
[chat][/chat]
winneratlife
Member
Member
Posts: 335
Joined: December 16th, 2009, 3:52 pm
Division: Grad
State: MI
Has thanked: 0
Been thanked: 0

Re: Mousetrap Vehicle C

Post by winneratlife »

I thought mousetraps were one time use: after it snapped, unless I deliberately reset it, the spring could not be wound again? After all, if the string falls off, there won't be any resistance on the way back like there was on the way there. This means either I use two different mousetraps or overshoot past the starting point. Also, I realized this last night, would the resistance provided by having to wind the string be a problem when going forward? Also, is this in any way better than the other cars, or is it just different?
robotman
Admin Emeritus
Admin Emeritus
Posts: 1447
Joined: June 29th, 2008, 7:37 pm
Division: Grad
State: TX
Has thanked: 0
Been thanked: 3 times
Contact:

Re: Mousetrap Vehicle C

Post by robotman »

Well not reseting it isn't going to stop the spring from winding so as it goes out the spring will gather energy to take it back and when it is going back the first mousetrap will gather energy to take it forward again. The resistance of the string depends on the leverage that the string has, if you have a mousetrap that just has a kill bar it will be extremely hard to get the string to pull it up and give it energy to take it back. so you may have to add an extending bar off the kill bar.

Each design is generally the same once you get it perfected its just the ease of perfecting them changes
I used a double mousetrap powering system with "fancy" winding when i did it a couple years back as a state event.
Edit the Wiki.
Upload to the Image Gallery
[medals]Get Medals[/medals]
[chat][/chat]
winneratlife
Member
Member
Posts: 335
Joined: December 16th, 2009, 3:52 pm
Division: Grad
State: MI
Has thanked: 0
Been thanked: 0

Re: Mousetrap Vehicle C

Post by winneratlife »

Okay, but in that case, I do have to let the string off, which, as I said earlier, would mean that the resistance I had going out won't be present coming back. How do I fix this? Maybe different mousetraps, or different string lengths?

Can somebody please give me a detailed explanation of how the thing works, along with maybe a diagram?

Thanks.
Locked

Return to “2010 Build Events”

Who is online

Users browsing this forum: No registered users and 4 guests