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anyone else done mousetrap cars for physics?
heres my design so far(minus all teh materials) in inventor
the square up front is the mousetrap which will have a lever arm attached to pull on the "cvt" on the intermediate axle this will give me variable speeds not just one. and then another pulley that goes back to the main axle. the wheels will be made out of desktop and laptop harddrive disks cnc'd out. i have the intermediate axle because my teacher has restrictive size requirements. the frame will be made out of foam board then covered in fiberglass and if i feel like it carbon fiber for looks. the 1/8th" shafts will be riding on tiny little open bearings for minimum rolling resistance. the grading as i remember it is the total distance travalled/time for the first 5m.
any ideas?
02-12-2006 16:05
Jeff K.
Nice.
We also have to make a mousetrap car for the physics olympics. My friend and I are doing a collaboration and we're making that, a joule car, the toothpick bridge, and a rube goldberg. I might also do the paper tower and the slow bicycle race.
We're also using pulleys to get the maximum distance out of it, since the competition is for distance.
Do you have to go for maximum speed, and what materials have you considered for the axles?
02-12-2006 16:30
Aren_Hill
the ranking criteria is the highest # of total distance divided by time it took to complete the first 5 meters. as far as axles go i don't really know steel is to heavy even that miniscule amount. but other things might bend. i'll probably end up with some sort of plastic.that way the only metal things are bearings and the wheels.
my theory for the grade is be in a quick acceleration gear for the first 5 meters then "shift" to a hard long pull for the rest of the trial. that way i'll end up with a fast car that goes aways.
02-12-2006 16:54
Brandon Holley
pretty sweet...just make sure when you do the "gearing" of your car that its not so much as to not allow the car to move....it requires some trial and error
02-12-2006 17:20
Gabe
Does anyone else find it amusing how we spend six weeks designing a 130+ pound robot, and then in school we're assigned to create a little mousetrap car? 
02-12-2006 17:36
Jeff K.
Nice, for our mousetrap and joule car, we're actually using carbon fiber axles. Balsa wood body because it's easy to work with and cheap. Our grading is easier. It just has to travel 5 m, and then the competition is for distance after that.
We were considering using a CVT, but a regular pulley would allow it to travel farther and it's easier to lathe. We don't need to pay too close of attention to it when winding it. Are you going to use string, or some kind of belt?
02-12-2006 17:47
Aren_Hill
it'll be string and i may use carbon fiber for the axles that sounds like a good idea. pulleys would cause alot of unnecessary drag. it'll be fishingline
02-12-2006 21:45
colin340
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Originally Posted by Gear
the ranking criteria is the highest # of total distance divided by time it took to complete the first 5 meters. as far as axles go i don't really know steel is to heavy even that miniscule amount. but other things might bend. i'll probably end up with some sort of plastic.that way the only metal things are bearings and the wheels.
my theory for the grade is be in a quick acceleration gear for the first 5 meters then "shift" to a hard long pull for the rest of the trial. that way i'll end up with a fast car that goes aways. |
03-12-2006 00:53
JoeXIII'007
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Originally Posted by Gabe
Does anyone else find it amusing how we spend six weeks designing a 130+ pound robot, and then in school we're assigned to create a little mousetrap car?
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03-12-2006 16:34
Rickertsen2
I'm soo sick of mousetrap powered anything. Right now i'm working on a 4"x6"8" mousetrap powered car for a class that has to drive up a ramp, maneuver over a 6" gap, press a button on one of the walls of the gap, drive down another ramp and stop on a line at the bottom.
Btw. I don't know if its legal in your competition, but if you take the mousetrap apart and just use the spring, you can extract alot more energy from it because you can rotate it further. The stock setup goes only 180 degrees. I've found that they will go at least a full rotation without yeilding. That gives you 4x the available potential energy.
03-12-2006 17:14
efoote868Very Cool!
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Originally Posted by Rickertsen2
Btw. I don't know if its legal in your competition, but if you take the mousetrap apart and just use the spring, you can extract alot more energy from it because you can rotate it further. The stock setup goes only 180 degrees. I've found that they will go at least a full rotation without yeilding. That gives you 4x the available potential energy.
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03-12-2006 20:56
Not2B
So, no one has mentioned one of the best mouse trap techniques ever...
Think about the force vector...and the direction the spring bar is traveling... and the direction the string is traveling.
For ease of design, you might want to keep the string perpindicular to the travel of the spring bar, so the force is transmitted to the string. Here's a little picture.
http://static.flickr.com/107/3134910...40497e.jpg?v=0
By the way - the CVT is an awesome idea. I did that for a mouse trap car in high school and it worked great! (We had to carry a can of pop on board.)
Good luck!!!
05-12-2006 00:20
65_Xero_Huskiewhat would be ironic, would to have a mouse actually ride on it 
02-01-2007 06:42
sanmausHello Gear and (all who built a mousetrap-car),
I study mechanical engineering in the first semester and I have to bulid a mousetrap-car like you.
Perhaps you can give me a few informations about what have you done.
I tried to add you in AIM, but I had Problems with that.
So, can you please send me an E-Mail: ich_bin_mausi@lycos.de
Thanks @ all who want to help me!
11-05-2007 21:43
Aren_Hill
i finished my car which ended up very similar to this and won the competition by going across our entire gym long ways and crossing the 5 meter mark in 2 seconds
11-05-2007 22:08
Smaugyeah i made one is 8th grade make the bar on the mouse trap longer and spin the spring a few more times it helps alot
11-05-2007 22:41
Scott Morgan|
i finished my car which ended up very similar to this and won the competition by going across our entire gym long ways and crossing the 5 meter mark in 2 seconds
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12-05-2007 10:16
cireWe had to make a mouse trap ball launching mechanism that could shoot a ball of our choice onto a drum and bounce into a box. We could take the spring off the mousetrap, I was the only one to do that and ours could shoot the ball quite well.
12-05-2007 10:19
VENI had to make one in gr9. I used cd's as wheels, lathed hubs for them, framing was aluminum angle with thin aluminum sheeting. it went 70 feet on the school floor
12-05-2007 12:08
Jeff K.
Earlier this year, I made an all wooden mousetrap car with the edges sanded down for the minimum amount of weight. Ball bearings throughout and just a 1spd pulley. Lathing down the wood I used for the pulley was a pain because it kept splintering. Carbon fiber shafts were pretty cheap and easy to get from my local hobby shop.
Got 1st for distance, since we didn't go for time, and went diagonally across the student center.
Here's the chassis, before final touches to get rid of the glue stains.
