Mousetrap car is an innovative vehicle which is inspired from a mousetrap. Yes, mouse trap as in traps for catching mice. Interesting, isn't it? These cars are very commonly used while teaching physics to help students know and understand physical science techniques and also helps in their science fair projects. It also contributes in building problem solving skills, developing spatial awareness, and time management in students. This project thus has a lot of benefits for students and to top it all, it infuses a sense of co-operation if a team is doing it. In case this intrigues you, the text below would probably quench your thirst of knowledge about mouse trap cars. Mouse Trap Vehicle Structure and Design This vehicle can have multiple mouse traps or huge mouse traps for added power. Four wheeled cars are very common, but there are 3 wheeled cars as well. For increasing the distance the car can travel, can be done by replacing the string which pulls the axle with the help of a rubber band. This car is powered by a helical torsion spring attached to a mouse trap. Consequently when you assemble a mouse trap, the spring is primarily twisted beyond its equilibrium so that it applies significant torque to the bar after the trap is closed. (Torque, is the tendency of the force to rotate an object.) The mousetrap bar, travels through an arc of around 180 degrees and that motion has to be applied and used to move the car's axle or wheels. If you do not want to do all this or in short start from scratch, these days you even get ready-made kits where you just have to assemble the car. There would be instructions given, so you need not think about scary things, like torsion, friction, torque, and so on! Now, let's move on to actually making it and see how to build a mouse trap car. Instructions Step #1 Gather the material needed. You can use different sets of materials. However, this one will be built using a mouse trap, 4 eye hooks, 6 balloons, 2 Bic pens (the smooth kind), 2 tops from pop cans, some string, 4 CDs/DVDs (expendable ones). Step #2 Make the sketch pens into hollow plastic cylinders by pulling the front and the back out of them. Then, what you need to do is taking the balloons, cut their top and bottom off. Stretch them over 2 CDs. These are going to be your back wheels. This will help in traction, as just CDs will be very slippery. Step #3 Take stock of whether the eye hooks fit over the pens. They cannot be 'just about there' as then they would not rotate. What we want is that they fit in a way which keeps them loose enough to rotate easily. However, they should not be lose enough as to rattle out loud. If they do not, just make sure you slightly bend them, leading them to rattle a bit. Step #4 Approximately, anticipate the center of one of those Bic pens and make a hole on that point. It has to be big enough to take the string. An easy way to do this is to screw the eye hook in the pen and taking it out. Step #5 Take the pen and push the string into it. Take it out on one of the sides. When the string is enough through the pen, tie something to the other end. Pull it back through and ensure that the object or knot stops against the other side of hole. Step #6 Now, along with the short sides, screw the 4 eyelets in the mouse trap. Try and maintain the depth, about the same. This will help the axle later going through them to be somewhat straight. Take care that you do not crack the mouse trap more than required. This is very important when it comes to mouse trap car instructions. Step #7 Insert the front axle- the hollow pen, by pushing it through the pop tabs. Pinch them to the pen to keep the pen moving from moving sideways and to keep those tabs stable. Further, to help them spin more freely, bend them away from the eyelet enough. Make sure it rotates properly. Step #8 Now is the time for front wheels. Wrapping a balloon around the pen fixed in the earlier step, try to fold it in a way that it is seems something like a wedge on the edge of the pen. Then rotate one of the CDs sans balloons on them on it. The direction should be the same in which you wrapped the balloon and wedge it on the pen. Point it as straight as possible and stable in connection with the trap. Do the same thing with the other end of the pen for your mouse trap car. Step #9 It is now the turn for the rear axle. For that push the pen, including the string into eyelet at the back. Let the strings be pulled through the eyelet to get them between the eyelet. In case you want to widen them, slide them through the gap. Follow that by tying the string to the top of the flap. This flap will move as the trap springs. Step #10 The rear wheels are to be attached exactly like the front wheels. Then, gently turn the back wheels in the backward direction. To be sure of the direction, put the mousetrap car on a surface and then pull it backward. Raise the flap slightly when it starts to catch, and keep turning till the trap starts loading. Continue doing this, until it is pulled, all the way back. Hitch it as you would generally do while setting up a mouse trap. It's important here to take a bit of care. If the string snaps, the trap will close in a jiffy, and anything in its way will get hit. Thus, avoid getting in that 'ouch' position by being careful. Step #11 Ultimately, to make your mouse trap car mobile, tap the trigger and there you go! If the wheels seem flimsy and stable, readjust them, get them straighter, and give it another shot. Hopefully, this time it should be well on its way, if at all it didn't for the first run! Mousetrap cars can be made from absolutely anything you use daily, except for the mouse trap, which has to be there! Of course, you can have variations and make it more sophisticated using different high tech tools and the likes! Good luck!