Tips for making your pyramid spin better
Deb, who is excited about getting her Rotating Christmas Pyramid to turn under candle power, shared the things she did to make it work:
1. I assembled the top section and dry fitted it then drilled the 7/16"-diameter hole in the roof and reamed it out to 15/32"-diameter perpendicular to the base using a drill press.
2. I waxed the center post and hole edges with paraffin wax (candle wax).
3. The nail that I used was a straight 1 1/4"-long finishing nail that I sharpened on the sander to a very sharp point. This reduced friction with the 5/16"-diameter acorn nut
4. With only upper and lower discs attached--no fan assembly--I gave the shaft a spin and it spun for 95 seconds.
5. The fan blades were made out of walnut 1/32 veneer. The size was just fine but the angle consistency of the blades was critical. The optimum angle was 25 1/2-degrees from the hub. The assembly with fan will spun for 65 seconds with no candle power.
It was fun building this pyramid and actually making it work.
Tom Sevy had a few things to add:
1. The candles should be as close as possible to the blades on the propeller without scorching the wood. Since different candles make flames of different sizes, it is difficult to specify the exact size that the candle should be.
2. Put a drop of light sewing machine oil in the acorn nut.
3. You might try putting the nail in a drill press (or even a hand drill) and then hold a file file to the point to sharpen and polish the point while the nail spins. This also "trues" up the nail to reduce the friction even more.