How To Build One Type of Mouse Trap Car

1  Purpose: To construct a self-contained vehicle powered by a single mouse trap

1.1  Materials:

This list is only a suggested starting point. Any material, as long as it's free or cheap should work as well as the store bought stuff. NO store bought cars may be entered in the contest for the $10.00 prize. These are a waste of time and expensive to boot. One memorable year a youth talked his dad into buying a seventy dollar kit. Then dad allowed the lad to assemble the car - with  the costly, predictable results.

1.1.1  Any brand of conventional mouse trap, ¹

1.1.2  Duct tape²

1.1.3  High density foam board³

1.1.4  4-CD's, or 45 rpm phonograph records⁴

1.1.5  steel axle

1.1.6  A steel clothes hanger

1.1.7  String

1.1.8  Superglue

1.1.9  Assorted Wood screws,

1.1.10  Rubber wheel⁵

1.1.11  Foam pad

1.1.12  Washers

1.1.13  Two 9cm steel axles - used for the project below

1.1.14  Assorted erector set parts, or similar items from a hardware store

1.1.15  Lead tape

1.1.16  Guitar pic

1.1.17  Two 1.5cm diameter wooden spools

1.1.18  Fishing line spool

1.1.19  Hot melt glue gun and glue⁶

1.1.20  Four Speed nuts

1.1.21  Two Faucet washers

1.1.22  Thread

1.1.23  Four Plastic axle clips

1.1.24  Black electrical tape⁷

1.1.25  4- Push-In threaded lockwashers

1.1.26  Any good quality lubricant⁸

2  Procedure:

1)

Cut two rectangular pieces of foam board, hot glue them together, and cover them with duct tape.

2)

Construct the gear assembly holder: build a rectangular base of dimensions ten cm x 6.5 cm from erector set parts. Attach two vertical eleven cm erector set parts to the base using a triangular brace.

3)

Construct the front wheel assembly holder: Use a frame of two four cm erector set parts, and connect them with a curved erector set parts on each side.

4)

Construct the rear wheel assembly holder: Use a frame of two 6.2 cm erector set parts, and connect them with two six cm parts, one on each side. Enlarge the holes at the end of each six cm part so that the rear axle will fit through them and turn smoothly.

5)

Assemble the extended mousetrap arm using the clothes hanger and a pair of needle-nose pliers, so that the bar is approximately 16.5 cm long, as wide as the mousetrap, and has a small bend in its end to which the car's string will be tied to. Connect the arm to the trap by wrapping it with the plastic string and applying superglue.

6)

Connect the mouse trap to the front of the previously assembled foam board chassis using four wood screws. Mount the front wheel assembly holder directly below the trap, using three wood screws, which should penetrate the trap, locking it in place.

7)

Mount the gear assembly holder on the back of the foam board chassis, allowing the two vertical erector set parts to penetrate the chassis. Fasten the gear assembly holder to the chassis using four wood screws. Connect the rear wheel assembly holder to the protruding erector set parts using screws and nuts supplied with the erector set. Use two wood screws to fasten the wheel assembly holder in place.

8)

Prepare two wooden spools by drilling four holes in each side of each of them, so that one unnamed metallic part may fit into each end of each spool. Insert the unnamed metallic parts into each end of each spool, and fasten them there with hot glue.

9)

Assemble the rear wheel assembly by cutting a 22 cm long portion of the steel axle, and sliding one of the prepared spools into the center of it. Fasten the spool in place with hot glue and two speed nuts, one on each side. Remove one side of the rear wheel assembly holder and pass the axle through the connected side. Re-attach the previously removed side of the wheel assembly holder.

10)

Prepare the rear wheels by using superglue to connect a pair of CD's, being certain to align them perfectly. Repeat this process. Superglue a faucet washer in the center of each wheel. Slide the wheels onto the rear axle, and use hot glue to fasten them in place.

11)

Using a nine cm axle supplied with the erector set, build the gear assembly. Slide the remaining prepared spool and the fishing spool onto the axle, and fasten them there with hot glue. Use speed nuts to ensure that the gears will remain stationary. Bend the gear assembly holder's vertical posts slightly, and ease the axle into place between the two vertical holders.

12)

Assemble the front wheel by sliding an erector set-suppled rubber wheel onto an erector set-supplied nine cm axle. Slide two washers onto each side of the wheel, and mount the axle on the front wheel assembly holder. Be sure to align the front wheel well, so that the car will move in a straight line.

13)

Attach a three meter length of thread to the large gear, and wind until about six cm remains unspooled. Attach a forty cm string to the extended mouse trap arm, run this string under the yellow string guide, and attach the end of it to the small spool on the gear assembly with black electrical tape.

14)

Using the lubricant, oil all moving parts: the mousetrap spring, all axle joints, the and the yellow string guide.

3  Conclusion:

3.1  If we are to be successful at building a functional mousetrap car using our knowledge of physics and plane geometry, then we must pay diligent attention to His Nibs Mr. Herkes.

3.2  I learned quite a bit about torque, gear ratios, friction, force, motion, mechanics, trial and error.  I also learned to put my dads tools away when I finished with them.

3.3  The end result of our many hours of work is a pretty cool mousetrap car.

Footnotes: