Helicopters B

Skink
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Re: Helicopters B

Post by Skink »

In other words, a new rubber band should be used weekly assuming we get in about five flights in a week? That gets a bit pricey. In any case, thanks, bro.
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Winding Stooges not allowed?

Post by gmui »

Hi,
Has anyone been allowed to use a winding stooge during Regional or States? I just got clarification from the NY state coordinator that students will not be allowed to attach anything to the supervisor's table nor bring their own table. Is that how it's been for previous years and/or for other states?

Seems like kind of an odd restriction. Should we just hold the torque meter?
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Re: Helicopters B

Post by jander14indoor »

I can see not being allowed to attach things to the judges table, I never allow it. I'm busy checking helicopters, etc, its just a good way to get your helicopter broken.

Are they providing tables for the competitors to set up on?

Not sure why you can't bring your own table unless not enough space where they are flying. Racquet ball, handball, squash courts have become very popular as they are relatively tall, typically have smooth ceilings, and are easy to manage to keep competitors seperate from inappropriate coaching. It would be a pain to have students moving tables into and out of a court.

There are work arounds. Mount your torque meter/anchor to a long board with easy hand holds. Have one student hold that as a stooge.

You might have your coach ask why the rule was implemented, I haven't heard of it being implemented anyplace else (except the judges table, that just makes sense for the reasons I mentioned).

Jeff Anderson
Livonia, MI
gmui
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Re: Helicopters B

Post by gmui »

Thanks for the reply. The event will be in. Big university gym so it's not the court issue you mentioned. Not using the judges table makes sense but I'm not sure why a small portable table wouldn't fall into the rule that says "Teams may bring any tools and their flight log." Wouldn't a winding stooge attached to a table count as a tool?

Will need to check again...
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Re: Helicopters B

Post by Inergy9118 »

1). Generally speaking is there any advantage of taking a smaller size motor and doubling it over instead of simply going with a larger motor? ie). would a doubled over 1/16" motor be the same as a 1/8" motor? Will it produce the same amount of torque. PS. where is a good source to get a torque meter?
2). We have constructed about 10 helicopters so far and wondering if there is any advantage of having both rotors free spining as opposed to only one (the upper rotor) free spining while the other is fixed. Wondering if the lower free spinning rotor adds any stability. We do not seem to see any signifcant difference.
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Re: Helicopters B

Post by jander14indoor »

1) Slight difference in turns per inch, if lube properly, not enough to worry about. Torque meters. There are a couple of suppliers out there, but I usually just build my own, see viewtopic.php?f=68&t=1822 for discussion of plans available on line.
2) How good are your times? If you are up in the two minute range, I think you have the answer. With data. The only difference I've seen is with both rotors free they spin around the same axis and seem to wobble less. POSSIBLY increasing flight times slightly.

Jeff Anderson
Livonia, MI
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Re: Helicopters B

Post by Inergy9118 »

jander14indoor wrote:1) Slight difference in turns per inch, if lube properly, not enough to worry about. Torque meters. There are a couple of suppliers out there, but I usually just build my own, see viewtopic.php?f=68&t=1822 for discussion of plans available on line.
2) How good are your times? If you are up in the two minute range, I think you have the answer. With data. The only difference I've seen is with both rotors free they spin around the same axis and seem to wobble less. POSSIBLY increasing flight times slightly.

Jeff Anderson
Livonia, MI


The link for the Torque meter is not working. Worried we can not get the rubber we need in time. Who do you recomend for suppliers of rubber?
Last edited by Inergy9118 on April 9th, 2013, 4:11 pm, edited 2 times in total.
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Re: Helicopters B

Post by mrsteven »

With only a minute, I wouldnt worry about those issues yet, I would concern yourself in making better helicopters to match to whatever rubber size you are using and optimizing it. The difference in 2 free and 1 free rotor is insignificant in my experience as well.

I use FAI rubber, http://domino-35.prominic.net/A55C2D/fa ... 42006D1051
A 1/4 lb will be more than enough to last a season. Ignore the 10/5/1lb and the prices. A 1/4'' is about $10 and is good for a long while.
Over 2 years of it and testing almost every day I think I totaled out at maybe 1/2lb of rubber. Possibly more but not by much. Though if time is an issue I would find local hobby shops and use whatever they have available and match the helicopter to it
2011 Helicopters State Runner-up
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Inergy9118
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Re: Helicopters B

Post by Inergy9118 »

HELP. What is the key of getting over a minute? We have tried a lot of things. What is the key? How many turn per inch should you have?
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Re: Helicopters B

Post by retired1 »

I normally use a value of 100 turns per inch, but this batch of rubber is breaking at 94 TPI, so our team used 90.

That assumes a lubricated band that has been prestretched after tieing the knot.

Better times are achieved by having the chopper as close to the 3 g min as possible, having the blades absolutely symmetric, a proper pitch and having the right width and length of rubber for your chopper.

Are you using a kit??
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