This is a neat idea I had, where you light candle at both ends then spin it lightly so that as the candles melt separately they try to balance by spinning.
Made out of k'nex!
Step 1: Parts and Tools
a tall candle,
a long, thin, straight nail,
a cutting board,
4 gray k'nex pieces
2 Red quarters,
32 purple quarter-spheres,
6 short green rods,
45 short white rods,
30 blue rods,
4 yellow rods,
12 orange rods (with the little separation at each end, though normal red rods would work).
Step 2: Sides
Build two of these, the photos should be clear enough.
Step 3: Connect
Once you've built both sides, add these nine rods onto one then connect them together like so.
Step 4: Tin Foil
Spread some tin foil on the base so that when the wax drips it won't get all over your floor/table!
Step 5: Prepare the Candle
If the wick is not exposed on both sides of the candle, cut off one end and sharpen it so that the wick is usable.
Then, put a nail through the middle. Be careful that it is straight and try not to break the candle.
Step 6: Light!
Light one end whilst holding the other, then light the other end.
You may have to hold it flat for a while so they really get burning...
After about sixty seconds, spin lightly