Helicopter Testing

[illusionist]

Methods and locations.

[chia]

I'm not really sure where to put this, but: what's up with the dime-sized "flat balsa wood disk" we need to put on our helicopter? It seems a little silly to me that if that comes off, timing stops. Is it to encourage people to test in flat-ceilinged rooms without obstructions so that it doesn't come off?

[chalker7]

I'm not really sure where to put this, but: what's up with the dime-sized "flat balsa wood disk" we need to put on our helicopter? It seems a little silly to me that if that comes off, timing stops. Is it to encourage people to test in flat-ceilinged rooms without obstructions so that it doesn't come off?

Some teams were attempting to put metal spikes on top of their helicopters and jamming the spike into the ceiling to increase flight time through the added friction. The balsa disc is intended to prevent that practice.

[chia]

Hmm. Wouldn't the disk itself increase friction to an extent also? Not nearly as much as the spike, of course, but couldn't the rules simply have addressed that problem directly by not allowing the "spikes"?

[chalker7]

Hmm. Wouldn't the disk itself increase friction to an extent also? Not nearly as much as the spike, of course, but couldn't the rules simply have addressed that problem directly by not allowing the "spikes"?

The issue is defining a "spike." Anything that goes into the rules has to be explicitly defined and easily measurable. We want teams to still be able to put standoff sticks on the top of their helicopter to keep their rotors, but it is actually very challenging for a lot of supervisors to accurately, carefully and quickly measure something as small as wire or individual sticks (which is why towers/bridges/boomilever/etc no longer have max/min dimensions).

[chia]

Okay. I just hope I don't end up with a 30-second time at states just because the thing came off, though

[chalker7]

Okay. I just hope I don't end up with a 30-second time at states just because the thing came off, though

My best advice is to make it a solid component!

[illusionist]

Chalker7, I absolutely love this year's helicopter rules. My thanks goes out to everyone who added these components

[chia]

Chalker7, I absolutely love this year's helicopter rules. My thanks goes out to everyone who added these components

I agree. It leaves a lot more freedom for experimenting (that Chinook thing sounds like a good challenge).

[chia]

Sorry for double posting, but I was thinking... a Chinook-style helicopter with two separate motors would be really hard to wind and launch, wouldn't it?

[illusionist]

that's what good partners are for...

[chalker7]

Sorry for double posting, but I was thinking... a Chinook-style helicopter with two separate motors would be really hard to wind and launch, wouldn't it?

....and design and construct and balance (if one of the rotors has more thrust than the other, it will start tumbling end over end). Hence the huge bonus. I'm really looking forward to seeing what everyone can come up with though!

[jander14indoor]

Sorry for double posting, but I was thinking... a Chinook-style helicopter with two separate motors would be really hard to wind and launch, wouldn't it?

I don't remember and I don't have the rules handy, but I don't think the rules require two motors, do they?? Can you say transmission?

Course that still leaves balanced rotor performance, design, etc...

Like chalker7, I'm looking forward to the creative solutions!!!

Jeff Anderson
Livonia, MI

[illusionist]

..............
Transmission?! On a sub-5 gram helicopter...
I think that would be very inefficient. There will come at least one point where there will be a perpendicular turn, and w/o a gear system or a universal joint that would be extremely inefficient, no?

[chalker7]

..............
Transmission?! On a sub-5 gram helicopter...
I think that would be very inefficient. There will come at least one point where there will be a perpendicular turn, and w/o a gear system or a universal joint that would be extremely inefficient, no?

I could see a belt system or a crank system (like on ornithropters) possibly working without gears and being pretty efficient.