Scioly.org

What kind of design are you using? If you tell us, we can fix it.

Also, I don't mean to be rude, but if you're in Div. B, why are you even doing Helicopter? Is it a B trial event in NY?

genius98, look at the following:
http://www.sciencenc.com/event-help/helicopters.php
http://www.youtube.com/watch?v=A6LHxF2hIWE
http://gallery.scioly.org/categories.ph ... 766a9c41ea

thewinner wrote:Also, I don't mean to be rude, but if you're in Div. B, why are you even doing Helicopter? Is it a B trial event in NY?

It is in Ohio!!

Yeah, it is in NJ, too. That's why I asked.

So have you guys noticed a large difference in times by tapering the motor stick/ shaving off unnecessary wood? with it being a min of 4.0 grams I would think it would make some difference..

If your helicopter is less than 4 grams anyway then no, it does not make a difference. All it does is remove excess weight, which is always good unless your helicopter is already under the minimum weight.

mrsteven wrote:So have you guys noticed a large difference in times by tapering the motor stick/ shaving off unnecessary wood? with it being a min of 4.0 grams I would think it would make some difference..

So the other day I decided to see how much better I could make the helicopter I built last year when this event was a trial. It was really lumpy... the rotor was awkwardly glued onto an Ikara prop hanger and reinforced with random sticks and loads of super glue, and the two blades of the free rotor didn't have nearly the same pitch. There wasn't much I could do about that, but I massed the copter and it came out to about 6.5 grams... mostly the motor stick. After copious amounts of shaving and sanding (resulting in loads of shavings and sawdust on my dining room floor >.>), I had the thing down to around 4.4 grams with half of the original motor stick gone (I had originally used an unnecessarily wide and dense piece of balsa). Last year its best time in the U of I Urbana armory was something like 10 seconds... on 700 winds, I kept it in the air for 45 in my foyer.

The way I designed my motor stick setup for the helicopter I'm almost done with (I had to put it on hold because of homework >8C), I could shave/taper the end which is supporting the fixed rotor only. The center of gravity ended up a little high (very slightly lower than halfway down), but I'm hoping lllazar is right and a long motor stick will make up in stability.

I use an extension for the fixed rotor, since it doesn't need the same strength as the motor stick. The extension is something like 1/8 by 1/16 and aroung 6 inches long. But trust me, the longer motor stick/spacing between the two rotors definetely helps with stability.

chia wrote:<SNIP>the rotor was awkwardly glued onto an Ikara prop hanger and reinforced with random sticks and loads of super glue,<SNIP>

Careful, while that was legal under the rules last year, this year rule 3.b reads: "The functional components (rotors, rotor blades, vertical stabilizing surfaces, and motorstick) of the helicopter must be constructed only from wood, paper, plastic film covering, and glue. The functional components must not be constructed from rigid plastic." The Ikara hub is plastic if that's what you mean by prop hanger. If you are ONLY using the prop hanger, but not the Ikara hub, you are probably OK.

Thanks,

Jeff Anderson
Livonia, MI