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How to Build a Mouse Trap Car - A Step-by-Step Guide

supplies needed

supplies needed

In the Fast Lane

Have you ever wondered how to build a mousetrap car? Maybe you have sat around saying to yourself, how does a car made from a mousetrap work? What kind of tools does it take to build one? Just who is going to drive such a car, my pose-able GI Joe action figures? What kind of miles per gallon will I get out of it? For me personally I always wondered if they have sports car versions, family sedans or mousetrap car limos. Certainly the possibilities are endless in the construction. It's truly all up to how fancy you want to make it and what kind of materials you are going to use. So let's go ahead and build a mousetrap car.

In order to build a mousetrap car you will need a few things. To start off simple, use these items:

  • Mousetrap
  • Dowell rods and Wheels (anything really can be used here like knex wheels and rods, lego tires and rods, tinker toys are great too.)
  • 4 Eyehooks
  • About 10 inches or more of string
  • Scissors
  • Ruler
  • Pencil
  • Drill
  • Drill bits (I recommend a 5/64 as most eye hooks will fit easily into the pilot hole made by the bit.)

Step 1

The first item of business to take care of is the drilling. Pick up your drill and load your 5/64 bit into the drill. The mousetrap has 4 sides, two longer sides and two shorter sides, then there is the top(with the trap itself on it) and the bottom. Take the mousetrap, (making sure it is not set), and using your pencil and ruler, you can draw a straight line through the middle of the shorter ends. Mark about ½ inch in from the sides of the trap on the line you just drew. These are the marks you will be drilling into for the pilot holes where you will screw in the eyehooks. To make the pilot hole for the eyehooks, drill steady and straight about a ½ inch into the mousetrap on these two sides. Once you have drilled four holes total, then you may take the eyehooks and screw them into the mousetrap. You now have the supports for your axles.

Step 2

For my example I will refer to the use of knex pieces. They are lightweight, easy to assemble and the tires will give great traction for the car. Take one of the knex posts, usually a light gray color, and slide it through the two eyehooks at the end of the mousetrap. There are small "stopper" connectors that you will snap in place to keep the tires from sliding into the mousetrap. These stopper pieces are going to be on the outside of the eyehooks. Once you complete that, put the tires onto the ends of the axle. Using a cap connector for the knex set, attach one to each end of the axle so that the wheel does not fall off of the axle while driving. Make sure that you do not make the connection too tight or your wheel will not spin around.

tinker toys can also be used for axles and wheels

tinker toys can also be used for axles and wheels

Step 3

Take your scissors and measure out about 10 or 11 inches worth of string. Its better to cut the sting longer than needed than to cut it short thinking you wont need as much. Remember the universal truth that cutting something shorter than needed is not possible to fix while cutting something longer than needed is able to be fixed. Tie one end of the string to the rear axle. This is the axle that will be closest to the coiled arm trap bar that swings in motion when the trap is activated. While you are working though the arm bar is not active and you will need to make sure to use the correct side. Measure the length again and cut off any excess over 9 inches. This isn't exactly necessary but it will add tension to make the car go farther and faster. Tie the other end of the string to the arm bar.

Step 4

You now need to wind up the string around the axle. To do this, you need to turn the tired of the rear axle in reverse to wind the excess string. While doing this, it will get to a point where you need to set the arm bar in place, (activating the mousetrap), to wind up all of the string slack.

mousetrap car in action

Step 5

Your mousetrap is now set and you are done. Well almost done. The mousetrap car is complete and now all you need to do to complete the process is set that baby off! Using your ruler, your hand could be in danger otherwise! If you cant get your hand out of the way before the trap swings shut and sends the car on its way, you will be in for a surprise. Use your ruler or a pen, something that can trigger the trap to swing closed while keeping you in the safe zone is the way to go.

using cds for wheels

using cds for wheels

the gears are similar to this in appearance

the gears are similar to this in appearance

How to Pimp my Ride

Some variations of building these types of mousetrap cars use pens or pencils for the axles and cds or dvds for the wheels. Well that requires some modification. The cds themselves will slip a lot on the ground when you set off the trap. Take a regular old-fashioned balloon and cut it into strips. Stretch the balloon around the cd edges and violla! You have traction. Since your average pencil or pen doesn't take up the entire center of the cd, you can also use the extra balloon pieces to fill the gap by wrapping the pen or pencil ends in the excess balloon pieces. Wanna motorize the car to run indefinitely? Here's an idea. Go to your local kids toy store and buy a motorized car or train piece. I recommend getting one of the motorized Thomas the tank engine cars. They are pretty cheap and battery powered. Take the train itself apart and you will have its "guts" so to speak. Its just a little battery powered motor with some gears on it. Take the bottom gear, (the one operating the wheels), and drill out the center of it so that you can slide it onto your axle. Depending on if you used a metal rod, pencil or knex rod will determine how much you have to bore out the inside of the gear. To actually add the gear, start threading your axle through one of the eyehooks, once through the first eyehook, attach the gear to the axle and continue sliding the axle through the gear and first eyehook until you are through the second eyehook and can attach the wheels. You can take the motorized section of the train and attach it to the mousetrap through either glue or small screws. Make sure that you are matching up the two gears, the one you attached and the motorized section. If the teeth of the gear are not interlocking, the car wont run when you turn on the motor. Granted this is not using the trap itself, but its still quite a feat to accomplish. And if you put the trap on the bottom of the car, you can add a lever that sets off the trap when you hit a wall and send the car flying in the air! If you want to customize the mousetrap, you can glue a glowing necklace to it to simulate neon runners on cars to. Then set your trap off in the dark and watch it light up your floor.


Its not Really Cheating

Some of you are asking, "what if I don't have a drill to make the pilot holes?" or, "what if my significant other no longer allows me to use power tools?" Don't laugh too much; I know some couples like that. Here is a cheaper and easier way to accomplish a mousetrap car. Go to your local toy department or dollar store. They have cheap monster trucks for sale. They are big and lightweight and have tractor tires, perfect traction for the little beastie. You can glue the mousetrap into the bed of these plastic trucks and tie the string to the trap arm and the rear axle of the plastic truck, just like you would have for the earlier model we talked about. The great thing about this is that the car is already built; you are just motorizing it with the mousetrap. Score on saving time and effort! Plus you have all kinds of style points. You may need to modify the bed of the truck or the housing for the rear axle using an exacto knife or utility blade. Be careful, this plastic is cheap and cuts easy, so the modification won't be difficult. The hardest part is not cutting yourself when the knife moves through the plastic like it was butter. The axle itself may be encased in plastic. Just cut a large enough hole in the casing to attach the string to the axle. Once the extra pieces of the bed/casing that were keeping you from laying the trap flat and/or attaching the string are cut out, you can now glue the trap to the floor of the bed and attach the string to the rear axle. This one may not win the science fair, but it will certainly run over the mousetrap car that kid down the street made!

  • Mousetrap Cars Project
    A great place to get an indepth look at a mousetrap car. There is an evaluation process, several example movies, hints on building and step by step directions on the required parts.
  • Introduction to Physics Field Day
    This link is to a lesson plan challenging students to make a mousetrap car for a physics field day. A great place to start when making a mousetrap car with guidelines and contests.
    When you follow this link you will get a short explanation of the how a mousetrap car works. It also has 2 examples of mousetrap cars that can be made.
  • Mousetrap Car Construction Tips and Ideas
    This website offers instructions and tips for mousetrap car building. You will have to pay for a lot of the information that they offer. The information is solid and well detailed.
  • Mousetrap car - Wikipedia, the free encyclopedia
    Looking for a solid definition of what makes a mousetrap car? This wiki entry is a great place to start. it shows common pictures of mousetrap cars and some basic physics principles to how it works.
  • Ultimate Mouse Trap Car Homepage
    This is a homemade website by someone who is showing off their mousetrap car. The car was designed as a physics class project and the site contains several detailed pictures of the car.

Humane Mousetraps

  • Homemade Humane Mousetraps
    Mousetraps are generally considered inhumane for how they catch a mouse. This site gives detailed instructions on how to build a humane mousetrap. Complete with video.
  • How to catch a mouse without a mousetrap
    This link goes over a method to catch a mouse without any type of mousetrap. It does offer another humane way of catching the mouse as it will not harm the little fellow. Pictures and instructions included.
  • Build a Humane Mouse Trap : TreeHugger
    Treehugger.com offers a variety of environmentally safe lifestyle options. One of their offerings is a humane mousetrap. It is a similar build to many humane mousetrap and has a few variations. Not as detailed as other sites.
  • Mouse trap project
    Excellent site offering very detailed instructions on how to build a humane mousetrap. This site includes step by step instructions with multiple pictures and a background story as to why the trap was made.


dkmayo on May 14, 2013:

Very interesting. My son and I will have to give it a try.

rtyr on January 08, 2013:

should we use CDs?

sasgfvedgh on December 05, 2012:

what!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! are u effing serious u mofo }:(

bjenk66 on June 21, 2012:

yeah same i got to do it for school aswell its easy but hard if you think about it

Badqurl Ppl from Sella Link 1138 on May 07, 2012:

This is boriinnnnqqqq whqat are yall tlkingg abt ppl are yall retarded man.......i hate thiz project gotta do more important things thn this shxt....

Savannah on February 22, 2012:

Well...me amd my partner tought we had a month to work on this cause that's when the grading period ended...yep..now its due in three days...shit

Savannah on February 15, 2012:

I have to make one of these for school...anybody got one that they got an A on that I could have?

wow on February 12, 2012:

You people need to learn how to spell and use correct punctuation. Honestly, grow up.

Nemmy1613 on February 11, 2012:

Thanks, gotta make one for school (Science class) hopefully this will help me :)

kate327 on February 07, 2012:

thanks the car i made using the steps really helped

66 on January 24, 2012:

Hi good

breanna on January 20, 2012:

hey people

casey on January 20, 2012:

i love the car

evan on January 13, 2012:

tis help alot

mrs rihan on January 05, 2012:

My husband was having an affair with someone from his workplace. I was so upset, I didn't know where to turn.untill a friend introduce me to SUNRISE SPELL which gave me the strength to confront him, and I won him back! The girl got fired, and now we are happier than we have ever been.... if you require any assistance contact sunrisespell@gmail.com

ur mom on December 11, 2011:

my phone number is 222-fuckyou

sexy man on December 09, 2011:

im the sexiest man in the world

the better one on December 09, 2011:

the one is stupid

the one on December 09, 2011:

im sexy and i know it

the awesome on December 09, 2011:

weeeeeeeeeeeeeeeeee this stuff is cool :]

its me yo momma on December 07, 2011:

i did her last night

its me yo mom on December 07, 2011:

yo this thing is bs it makes no sense

Cookies on December 07, 2011:

Cookies AND Monsters

Its Pesonal on December 07, 2011:

Its F****ing hard

american on December 06, 2011:

to long to write or read

yaaaabuddy11 on December 01, 2011:

i hate thiss!!!!!!!!

amazing1234 on December 01, 2011:

i dont understand this.... (:

kyle on November 25, 2011:

it help alot thx

Bree on November 08, 2011:

Hey yall! :)

Dylan Beaver on November 03, 2011:

I'm to black for this website ;) any takers????

hahaha you lost the game on October 31, 2011:

i like me some delicious pie with some mexicans and blacks in the middle

robert on October 19, 2011:

this is stupid !!!!!!!!!!!!!!!!!!!!!!!!!!!!!

bobbie hauger on October 14, 2011:

how do u build a mouse trap car obbie

scool on October 13, 2011:

hv 2 do 1 4 scool ... :(

A Kid on October 11, 2011:

love you too honey

Gaaabby[: on October 05, 2011:

i love you ?

rawrz132_addmeonmoshimonsters on September 29, 2011:

OMIGOSH! I hav 2 build 1 4 school :(

rawrz132_addmeonmoshimonsters on September 29, 2011:

OMIGOSH! I hav 2 build 1 4 school :(

Dancing With Pandas on September 15, 2011:

wow the maturity on this site is like -900

isabel :) on September 10, 2011:

this is a really boring assignment and is giving me the shits!!! ARGGG

joshdemo1234 on August 29, 2011:

it had helped alot thankyou

joshdemo1234 on August 29, 2011:

it had helped alot thankyou

cha cha (bee sting) on July 23, 2011:

yes it may be true that i got stung by a bee, and michael no need for the cha cha, i know im the best dancer at st. bernadettes. ANway making these mousetrap cars and racing them down the halls and then sneaking on the school computer to write these comments back and forth to each other were some really amazing memories that i will remember always. T

metaxeirismena aytokinhta on July 17, 2011:

watch out mouse.I really had hard times which this creature.I gonna use this tips to them hopefully they not come in our place anymore....I had this incident with them,It happened that i forgot to close the door of my metaxeirismena aytokinhta

μεταχειρισμενα αυτοκινητα on July 10, 2011:

watch out mouse.I really had hard times which this creature.I gonna use this tips to them hopefully they not come in our place anymore....I had this incident with them,It happened that i forgot to close the door of my car ?????????????? ?????????? .

v nbhmhnmk on June 01, 2011:

hey yall lol.

yuvrajthapar@rocketmail.com on May 30, 2011:

very nice

POO ON YOU on May 21, 2011:

Poo on you, Poo on you put my butt on your face and, POO ON YOU

lesley on May 16, 2011:

um lilbrat hii

lesley on May 16, 2011:

wow tis is extreamly awquard u guys r not even commenteing about the mousetrap cars ha some world we live huh!!!!!!1 lol:0

Anyhow on May 14, 2011:



poop poop on May 07, 2011:


nobody cares ***** on May 02, 2011:

True. This site is crap, but all of you people here submitting comments are being total jackasses. Not only to the other people commenting, but also to the person who made this site.

P.S. Nobody cares if you are gay... so shut the !@?* up.

lentocean on April 26, 2011:

perhaps this was exquistite to my knowledge

Candy on April 20, 2011:

HEYyy This IS Confuzzzinggg Seriouslyyyyyyyy

ghn on April 13, 2011:

you ppl are home

Ginger on April 06, 2011:


to who puts the STD in STUD on April 06, 2011:

to whome it may concern,

Michael has been tested and is positive for hte SNEYD DISEASE!!!!!!

Gazelle on April 06, 2011:

gazele Hunter,

I am here for natures purpose and for the beauty of human beings.. please dont hunt me it only gives you humans a bad name.....


The Gazelle

True. on April 03, 2011:

True. This site is crap, but all of you people here submitting comments are being total jackasses. Not only to the other people commenting, but also to the person who made this site.

P.S. Nobody cares if you are gay... so shut the !@?* up.

GazelLehunter on March 26, 2011:

Yo yo yo me and my boy fingertips attacked a gazelle this week

Michael.......is.......welliwontfinishthat on March 24, 2011:

to a certain someone out there who made certain someones laugh so hard today in math essentials.......why cant you be a little more creative with the names for these comments *cough* towards us who won the chocolate bars for the best car!!!!!

mason logan on March 24, 2011:

i hate this stuff i cant a read and a havvvv-vve a stut-tter--iiing pro-bb-b-lem......meow ^..^

= _-_=

Beandip on March 23, 2011:


IREDIT on March 23, 2011:

IREDIT (Weblink from the beautiful Phillip Mycarr)

~Dr. Phil Oso. Pher~... PHD homie on March 23, 2011:

What do you think i think that i am thinking about thinking with thoughts that really make you think and if you think about it i really shouldnt have thought so much


obamamobile on March 23, 2011:

I made a mousetrap hybrid...

Phillip Mycarr on March 23, 2011:

if you wanna see a better mousetrap car design go to


long deek on March 23, 2011:

herrow i yam seexty sheven yers orld and i yam trippin on rice prease

Hater 24/7 on March 23, 2011:

Mice n tyson ur so ridiculous i saw ur mousetrap car with spinners and it was sick. i remember that day too when ms. smith told you to go to the bathroom it was carzy. yea life be trippin over sometime ago

bigcockmuffins on March 21, 2011:

i like how people are commenting on mousetrap car designs, yea i have a life and comment 24/7 on random people who i dont know complaining how life sucks while making mousetrap cars and saying "i'm so sexy and smart" hahaha get a life

lauren on March 21, 2011:

your car suuucks

house of houses on March 11, 2011:

my teets hurt

runny chicken on March 11, 2011:

"thats cute i remember when I grew up...."


house of cards on March 11, 2011:

house of cards

COUL PEOPLE on March 11, 2011:


imma bee on March 11, 2011:

Sarah got stung by va bee

COUL PEOPLE on March 11, 2011:


Mice 'n' Tyson on March 11, 2011:

Dogg imma put some spinnas on my trap G. i remember one time i waz at skool and my teach to ME to go to the bathroom. i ain't never ever had a teacher tell ME to go to the bathroom i usually ask myself. ya no wat i mean kid. life be trippin sometime ago. later later

jaxon mousetrap on March 11, 2011:

dudely, i totally feel this article. seriously me and my amigos are def. going to build a mousecrap car and race them. narley brococho. piece love and care outage

sammy on March 02, 2011:

to weirdo girl at top yes you r stupid

That long hair dude in the corner of the class on February 21, 2011:

I wanna make one

KyvakRose on December 07, 2010:

Pretty helpful. Thanks for giving a step by step guide.

*cough* on December 03, 2010:

i have to make one of these things in my class and then we r gonna have a race on the longest distance and the fastest speed........ im not liking it so far......wonder if it will get better.......


anonomous on October 27, 2010:

wow that is pretty amazing and im supriised at how many things u can use for a mouse trap race car! especially the tinker toys thats pretty awesome!

Deviled Eggs on October 06, 2010:

Thanks for this hub! My daughter is going to try and build a mouse trap car today after school and I plan on having the toy truck as a backup plan. Great idea!

yoli on June 22, 2010:

Wow! nice info...Thanks for that...I have found another related site about mouse trap. Come and check it.


miss thing thing on January 13, 2010:

i hate building these thing when i tried my finger got snaped at it didn't hurt at first but then it stung real bad

car repair on December 11, 2009:

Hahahahaha this is definitely the best way to make use of a broken car!

emily on December 05, 2009:

i have to build one for school and the back axle is turning but the car wont move hhhhhhhheeeeeeeeeelllllllllllllllllllppppppppppppp

hi on November 17, 2009:

this helped thnks

kelly on September 28, 2009:

that is so kool

hopeful... on July 21, 2009:

i have to do something like this for a school assignment... hopefully it's gonna work out...

looks good so far, and not too expensive either!

i love school on April 27, 2009:

these kinds of prodjects are so fun and worthwile. in fact, i do these for fun on weekends! i can't wait to get started on a mousetrap car! im so happy that we get to do hands on experiments in school. thank god im a genious and get to beat everyone in another science compition.

mia on April 27, 2009:

i don't get the last part

gay on April 20, 2009:

i have to build one of these for shop and i wanna be the winner any ideas ?? to build the ultimate car ???

olivia on March 27, 2009:

ughh i have to make one of these for my school prject thing!!

yuck. maybe ill just buy a toy car or whatever and put the mouse trap inside.

jimmy on March 25, 2009:

i can build 1 of these on my 6 grade science fair

portia on March 19, 2009:


pyles class on March 19, 2009:

wil the string snap the asxle