SEN 1477
- Details
- Category: Archive 2010
- Hits: 1775
- Capacitors Revisited
- Capacitor Question
- Lottery
- Finals - Final
- More Ike Glider info
Capacitors Revisited
The recent SEN discussions regarding F1Q performance prompts me to
describe some recent results with supercapacitor-powered Indoor
models. The inspiration for such a power source was from Vin Morgan
in SEN 1217 (30 May 2008). A friend, who happens to be an EE, and I
developed a new aeronautic event for the USA Science Olympiad
tournaments. The SO had decided to drop the rubber-powered Wright
Stuff event out of the rotation for a few years to our dismay. The
airplanes are limited to one 10F 3V supercap for power. Charging of
the cap may be accomplished only by use of two AA alkaline dry cells.
Total all-up mass of the airplane must be greater than 12 grams. Wing
dimensions max 40 x 10 cm. Under these conditions, the airplanes have
demonstrated performance of over 2.5 minutes in very high ceiling
sites. The Science Olympiad has eagerly placed the event into the
official "Trial" stage, meaning that if enought interest is generated
it will become an official tournament event next year.
One attraction of the event is that no special equipment is required
to test compliance to the rules. The other attraction (as pointed out
by Morgan and Bauer) is that the power is self-limiting...quite
similar to that of a rubber motor. Capacitors are labeled and
dry-cells can be visually inspected. Teams are required to start with
a discharged capacitor to discourage over-charging prior to flying.
It seems to me that a similar set of easy-to-follow restrictions for
F1Q may be worth testing to produce an event with simple requirements
to attract a larger following.
Chuck Markos
Capacitor Question
How much variation is there in the manufacturing tolerances ? - It would seem that one might want to test the capacitors, just like one test rubber to get that extra 5% capacity?
Also how many would be needed to provide a F1C or even F1P level of outdoor performance?
How much variation is there in the manufacturing tolerances ? - It would seem that one might want to test the capacitors, just like one test rubber to get that extra 5% capacity?
Also how many would be needed to provide a F1C or even F1P level of outdoor performance?
Lottery
Walt, Martin and Roger,
Your system is very nice if we fly indoors. But you miss the very essence of the subject. Instead of lottery you just made it triple lottery.
I remember one moment as it was yesterday:
I was timing Matt Gewain in the morning 10 minutes fly-off at the finals. My large 10*70 binoculars are perfectly adjusted and the lenses are wiped out clean. Matt makes good launch; transition; model goes to glide. Looks like it should make 8 - 9 minutes. Than, at about 3 and a half it just disappears into the fog! It is still 300 feet high! So did 5 or 6 other models. Actual flight time was 8-9 minutes for best models; the low-under-fog-flying model made 5 minutes and was observed to the ground...
In the end it was luck only to decide the team. Nothing to do with the fair competition. This is not the only story of this kind. Similar situations will happen again and again as long as it is single point failure system.
Alex Andriukov
Finals - Final
The in person TSC meeting is this weekend - fortunately :-)
Ike Glider info
There is additional information of the Ike Winter Classic HLG CLG events on the link
http://www.faifreeflight.org/images/stories/contests/IsaacsonGlider.pdf
...................
Roger Morrell