One of my sons friends stayed over yesterday and mentioned in passing he'd been assigned to make a mouse trap car for school. I thought about how I had lots of fun making those way back and decided to make one out of scraps off my desk and document it. It's far from the best one ever and unlikely to win any awards, but it does work.

Step 1: Supplies

I used the following:

A mouse trap
4 eye hooks
6 balloons
2 bic pens (the smooth kind)
2 tops from pop cans (for the serious perhaps washers, or otherwise any other bendable metal)
some string (not pictured)
4 CDs/DVDs (expendable ones). Here 3 CDRs and a blank transparent thing from the top of a spindle. I hear DVDs are a bit lighter, but I'm not optimizing that hard.

Step 2: Strip the Pens

Pull the front and back out of the pens, making them hollow plastic cylinders.

Step 3: Cut and Apply Two Balloons

Cut the top and bottom off on two of the balloons. Stretch them over two of the CDs, which will later be the back wheels. This will help traction a great deal as CDs are otherwise pretty slippery.

Step 4: Check Eye Hooks

Assure yourself that the eye hooks fit over the pens. They need to be loose enough to rotate easily, but not so loose that they rattle too much. If not, bend them slightly so that they do. Mine were a bit small and needed to be bent out a bit.

Step 5: Make a Hole

Make a hole roughly in the center of one of the pens. I did this simply by screwing one of the eye hooks in and ten removing it. It needs to be large enough to take the string.

Step 6: Thread the Pen

Push the string into the pen and get it out one of the sides. I pushed it in and blew on one end, then jammed then ink part I'd removed earlier in, cussed at it a bit and then did it some more. Eventually, when the string is through the pen, tie something to the other end. This one is with a small piece of a toothpick. A simple knot would probably do in most cases, but my thread was a bit thin. Pull it back through and make sure the knot/object stops against the other side of the hole.

Step 7: Put Eye Holes in Trap

Screw the four eyelets into the mouse trap along the short sides. Try to get them to be roughly the same depth so that the axle that will later go through them is somewhat straight. Also, take care to not crack the trap too much. More ambitious builders may want to pre-drill holes, but I went for broke and indeed it cracked a bit, but not so much that it didn't work.

Step 8: Brace

Insert the front axle (i.e. then pen without the hole/string) pushing it through both pop tabs (or whatever you've managed to get). Pinch them to the pen so that they won't move too much and keep the pen from moving sideways. Bend them away from the eyelets enough so that they can spin freely against it and give them some leeway from it (not snugly pressed against it). Make sure it can rotate ok.

Step 9: Front Wheels

Wrap a balloon around the pen you just put in, trying to fold it so that it's somewhat wedge-like toward the edge of the pen. Gently rotate one of the CDs without balloons on them onto it in the same direction you wrapped the balloon, wedging it on the pen. Attempt to get it to point fairly straight and not wobbly in relation to the trap. Repeat for the other end of the pen.

Step 10: Rear Axle

Push the pen with the string into the back eyelets. Pull the string through the eyelets so that it's between them (or slide through the gap if you had to widen them). Tie the string to the tip of the flap that will move as the trap springs. Those more ambitious might want to brace it with something between the spring and the back to make sure it doesn't snag or fray, but I didn't bother, which does mean the string gets tangled or frays every so often.

Step 11: Back Wheels

Attach the back wheels in the same way the front were done.

Step 12: Wind Up

Gently turn the back wheels backwards (if your unsure of the direction, put it on a surface and pull it backwards). When it starts to catch, lift the flap slightly and keep turning until the trap is starting to load. Keep going until it's pulled all the way back, then hitch it as one normally would setting a mouse trap (see instructions on package I guess).

Take a bit of care, because if the string snaps the trap will indeed close (quickly) and anything you have in the way will get hit. It's not exactly deadly, but not pleasant either - these things do pack enough power to make you go "Ouch".

Step 13: GO!!

Tap the trigger and watch it go. Readjust the wheels (which are a bit flimsy with the low-rent balloon support) to get them straighter and retry. It's not very crash resistant, not very pretty, but very easy to make and can, if you're me, be built entirely out of things you can reach from your work chair (yes, that included having an old pack of mouse traps on my shelf).
<p>how long and how wide dose the wood need to be</p>
<p>how long is the string</p>
<p>Fisheadope</p><p>Why don't you make it 4 wheel drive, when the bar of the first m/trap reaches it's travel end, it trips the 2nd m/trap and drives the front wheels , you would need to up the gearing to suit !</p>
Tape is better than Balloons for this kind of Mousetrap Car.
<p>What was the maximum distance traveled?</p>
<p>I still haven't got round to making this, can't wait to start!</p>
<p>im making one for science class and it better work</p>
<p>this is really cool</p>
<p>i gotta make this for school</p>
<p>me too</p>
<p> Same!!! Lmao!</p>
<p>same lmao </p>
<p>Does it go 5 meters?</p>
<p>I know this thread is really old...however if anyone is avail to answer~<br>Why does the front axel have brace's on it (the can tabs) but not the back axel?</p>
<p>To keep the front wheels straight and aligned</p><p>I believe that if they weren't there the car would turn a little to the left or right</p>
<p>also~ if you use balloons (or rubber bands) to fit the disks~ would it be beneficial to hot glue them in place so they don't slide? </p>
<p>Thank you for the advise</p>
<p>How far does it go?</p><p>More than 5 meters?</p>
<p>which size mousetrap</p>
<p>This is just so cool! I have to make this for the school! thanks for sharing! It's so exciting to watch the video..... (minus the ouch part!)</p>
<p>is there anything I can use instead of eyehooks</p>
<p>Virally anything really. Screws/wire or some bent metal perhaps. I'd probably stick to screwing whatever onto it rather than glue or tape - it gets yanked around quite a bit when it moves. Any wood screw works tho - find some broken thing and raid. </p>
<p>i made it it mad 6 times before falling apart</p>
<p>I made it but it lasted 5 runs before collapsing</p>
<p>make it come back and I'll be impressed.</p>
<p>wow that is good I'm 19 years old and mine would have never been that good??????????</p>
<p>Cool, I will use this for my science assignment since I otherwise would have no idea how to build one. Thanks, hopefully I build it right XD</p>
<p>next step AI</p>
<p>can any help me with step 8 my mind is so out of it i don't know what to do</p>
i tried to make this &amp; for some reason the car will not move. any advice?
<p>I made one and it works great. I honestly thought that it wouldn't work but it did.</p>
<p>hope this works</p>
<p>About how far does this go? My sience rubric requires it to go at least 12 ft..</p>
Nice. I made one of these in my Engineering class a few months back. My team did pretty... bad. We got stuck with two know-it-all sophomores, a girl who was afraid of tools, another girl who just wanted to get her math homework done that she didn't do the night before, and me... the shy, quiet girl who had ideas but couldn't voice them. D: (Haha, I'm not trying to make my team look bad, by the way. We all became friends because of that project. xD)
Oh, also... This is what we ended up with. (The first image is my design. We tried to follow it but somehow ended up with... the second image. >.<)
<p>What website/book did you use???</p>
<p>i made it and it was so fun</p>
<p>Hey, will this car go 5 metres? I have to make one for my Physics class, and it has to go 5 metres and not weigh more than 3/4 kg.</p>
<p>How can you make the wheels more secure without using the balloons?</p>
<p>mug awesome reids not </p>
<p>mug awesome reids not </p>
<p>mug awesome reids not </p>
<p>Beautiful art work.....</p>
<p>i didnt made anything . but i hope people could show me there images so i casn have a idea</p>
<p>cool i like how you made the mouse trap car</p>

About This Instructable




Bio: Mostly a programmer and random computer guy, but like to mess with hardware and other real life objects sometimes.
More by LarrySDonald:Vibrobot from old camera Clay Koch Snowflake Padlock shim from can without tools 
Add instructable to: