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Mouse Trap Cars: Making an Axle Hook

January 19, 2012

An important part of a mousetrap vehicles propulsion system is the axle hook. Learn how to make and attach an axle hook in order to propel a mousetrap racer.

A mousetrap powered car is a vehicle that is powered by the energy of a wound-up mouse trap's spring. The objective with all mousetrap vehicles is to turn the potential energy of a wound-up mouse trap's spring into the kinetic energy of motion. The most common way to propel a mousetrap car is to attach one end of a string to a mouse trap's snapper arm and the other end of the string to an axle hook. There are many different ways to make an axle hook but the most important part to any propulsion system is for the string to properly release it's self from the drive axle. If the string does not properly release from the drive axle the string will rewind around the drive axle and cause the mousetrap car to come to an instant stop.

how it works: The most basic mousetrap vehicle propulsion system is to tie one end of a string to a mouse trap's snapper arm and then wind the other end of the string around a drive axle.

Zip-Tie Axle Hook

This method uses a small zip-tie that is glued to the drive axle. These zip-ties are available through the Doc Fizzix website and are also included in our Essential Project Packet. The Essential Project Packet contains all the small parts that you need to get your project from the start to the finish including our "easy-to-wind" and "snag-free " string release system that will not tangle or snag, a technique developed exclusively by Doc Fizzix.

step #1: A small zip-tie is positioned in the center of the drive axle and locked in place.

step #2: The zip-tie is trimmed and cut so that the excess tail of the zip-tie. Make sure to trim the excess zip-tie tail as close as possible to the locking hub.

step #3: Super glue the zip-tie to the axle to make sure the zip-tie axle hook does not slip when under tension.

step #4: Catch the zip-tie axle hook with the string loop and wind the string as normal.

Wire-Hook Method

In this method a small wire is wrapped around the drive axle and then glued in place. This super fine wire is also available through the Doc Fizzix website.

step #1: Wrap a small piece of picture frame wire two times around the axle as pictured.

step #2: Twist the ends of the wire together until the the wire is tight against the axle.

step #3: Cut the excess wire so that the hook is just a small nub. The hook should be no stick up no longer than 1/8 of an inch. Catch the wire axle hook with the string loop and wind the string as normal.

step #4: Place some super glue on the wire to bond the wire to the axle.

Pin Method

The idea here is to drill a small hole in the drive axle and the insert a small dowel or pin into the hole. The hole is drilled the same size as the pin and then the pin is glued in place. As with the other options stated in the article, the pin should be cut short so as not to tangle or snag the unwinding drive string.

step #1: Drill a hole in the center of the axle that is the same diameter as the hook wire.

step #2: Place the wire hook into the drilled hole and then glue in place.

step #3: Trim the hook as needed so that it will not snag the string.

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