You can set this assembly on top of the wrapped package. If you are so sure of yourself that you've made no errors and that the batteries will ...
My new son in law will be traveling a great distance and spending his first Christmas with us. To celebrate, I thought I would make one of his packages a little different. A scrolling message tag will say, "Merry Christmas, Forrest." A solar powered mini car will race around in circles on top of the package (it is powered by a light above the package). If you get too close to the package to examine things, a voice will say, "Step away from the package!"
You will need a solar powered mini-car (thinkgeek.com). Carefully drill a 1/16 inch hole in the side.
Step 2: Cut thin plywood to match top of your package.
I cut a 12 inch by 12 inch piece of 1/4 inch plywood to match the top of the package I'm wrapping.
Step 3: Cut standoffs for the base.
I cut four 1 1/2 inch by 1 1/2 inch blocks of wood. I cut them 1/12 inches long (cubes).
Step 4: Cut pvc pipe for sound amplification
Cut a 3 inch long piece of PVC pipe (1 7/8 inch outside diameter). This will be used to hold the motion sensor and the speaker (makes the sound much louder).
Step 5: Find spot for PVC placement
Select a place to mount the PVC tube. It must leave room for the mini-car to operate.
Step 6: Drill hole for pipe.
Drill a 1 7/8 inch diameter hole for the PVC pipe.
Step 7: Drill hole in the pipe for motion detector
Drill a 7/8 inch hole in the PVC pipe (near an end) for the motion sensor.
Step 8: Glue standoff blocks to plywood
Glue the blocks in the corners of the plywood.
Step 9: Add battery holder
Fasten (with two small wood screws) the battery holder (3 AAA unit) to one of the corners.
Step 10: Mount on/off switch
Drill a hole and mount the on/off toggle switch.
Step 11: Drill hole behind PVC tube hole
Drill a 1/4 inch hole behind the PVC tube hole. This will be used to run wires, so make sure it is on the side that will be least obvious when the package is displayed.
Step 12: Drill hole for paper clip
Drill a 1/16 inch hole for a paperclip. The paperclip will go through the wood base and the upright portion of the clip will become the "pole" in the center of the circle around which the mini-car operates.
Bio:@EngineerRigsby My blog on simple 3d design is at http://www.simple3d.tumblr.com/ I've also written an app, "How To Make A Science Fair Project." I am the author of "Doable Renewables," "Haywired"...read more »