2003-08-29
Take-tonbo
The Take-tonbo is an ancient Chinese invention. The word means "Bamboo Dragonfly". Apparently it is now popular in Japan, and is a very common toy there. My first experience with one was when my best friend in high school, Brett, went to Japan as an exchange student. He brought back quite a few.
Tonight I was experimenting with bending paddle pop sticks over a flame. The general idea was to make wings for tourbillion/helicopter pyro devices, but once I saw the shape I had formed it reminded me of the Take-tonbo I had played with years before. I quickly burnt a hole through the stick in the middle (using a metal kebab skewer heated to red heat - rather than a drill which would have split the flimsy timber stick) and inserted a bamboo kebab stick.
This is a very quick and easy way to make a Take-tonbo. It took probably less than 1 minute from lighting the burner to trying it out. The traditional helicopter-like device has a solid chunk of bamboo as the rotor which has to be carved or sanded to form airfoils. That is quite time consuming, although probably works better, not only because of the shape, but because of the extra mass (times radius squared :-) in which you can store more energy on launch.
There is a lot of physics in this little toy, it would be a great thing to build with children. It isn't particularly dangerous, but it could hit someone in the eye if abused - the usual "don't be a moron" disclaimer applies. This design in particular is nearly instant gratification, although the flame required to bend the stick has to be used carefully. You will probably char the stick quite a lot, perhaps even set it on fire a few times. You might try soaking the stick first. Have fun!
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