Initially this build started out as an idea to hack a child's science toy anemometer into a speedometer for my longboard, unfortunately I somehow broke the circuit which operated the lights,and I lacked sufficient knowledge of electronics to work out what I broke.so I lowered my sights and thought, well as I'm here and the soldering irons on, I might as well make this.
Step 1: Tools
You will need:
A glue gun
A soldering iron and solder (or cold solder)
A small screwdriver (flat or Phillips head depending on which bolts you use)
That's it !
Step 2: Parts You'll Need
1 small 3v motor, you can scavenge from cheap rc cars or get of ebay for next to nothing
2 garden plant labels
2 small bolts with nuts
1x l.e.d (brightest you can find) mine wasn't that bright
A small worm gear with a 3mm bore (not pictured) I only had one and I made the instructable after I made it
Some paint if you want ?
Step 3: Soldering It Together
Solder the two leads of the l.e.d to the motors solder tabs (it doesn't matter which way round, we will worry about that later)
Step 4: Marrying It Up
Ok, it gets a little confusing now, after putting the worm gear on the motor spindle, spin it between your fingers and see which way it has to spin to light up the l.ed (if it doesn't work either way at first,spin it harder)
We want the solder tabs on the motor to be facing up to keep it a bit safer from the stresses faced by the undercarriage (see picture), now we need to put it on the side in such a way that it spins the way it needs to light up the l.e.d it's tricky to explain but you need to set it up so that when the wheel goes forward the motor spins the right way, sorry for my vagueness on this step, but it won't take you long to work it out :)
Step 5: Glue on the Labels and Drill Holes
Ok, with that done we now know which way to put the labels on, glue them on, then drill holes as shown, put the bolts through and your done
N.b the bolts need to be done quite tightly so that the whole assembly doesn't move and the gear disengages from the wheels' surface
Step 6: Use!
This set up could be used for seeing without street lights if you had a brighter l.e.d than me also you could improve by wiring two or three in parallel to improve brightness, I would have done this but I had no matching l.eds
It's ok just as a safety light so cars won't miss you at dusk :) or you could just use as lightweight, eco friendly under board lighting system with different colours,(slightly naff, but whatever it's geekily satisfying and cool)
Step 7: Extra Stuff
Sorry if a little vague at times, it's my first instructable so cut me little slack :) if you come up with any improvements then comment if you can be bothered ;)