Duration

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chia
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Re: Duration

Post by chia » January 16th, 2011, 7:36 pm

Wouldn't the rotor axes being spaced too much make it unbalanced?
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Re: Duration

Post by illusionist » January 16th, 2011, 8:22 pm

I can also say that my helicopters do better with a greater distance between the two rotors.
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Re: Duration

Post by jander14indoor » January 17th, 2011, 6:29 am

chia wrote:<SNIP> caused by the rotor axes being too far apart? I tried clay (it's underweight anyway)... ? Something to think about when I make my next one
Are you speaking about large spacing between the rotors, or whether the rotor axes are in the same line. Three things affect wobble that I've seen.
- Unbalanced blades, minimize that.
- Uneven pitch between blades on the same rotor, minimize that.
- And what I think you are talking about, rotor axes not being on the same line. Large spacing between rotors probably helps hide this. Reducing the out of lineness between the rotors definitely helps this. Smoothest helicopter I've had had the rotors exactly in line (hollow tube for the motor stick) and closely spaced rotors.

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Re: Duration

Post by baker » January 20th, 2011, 11:39 am

At an Invitational we saw times between 1:30 and 1:55 in a 20 - 25 ft gym. What times have anybody else seen this year?

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Re: Duration

Post by eta150 » January 20th, 2011, 2:52 pm

This is hearsay, but apparently the best seen so far is about 2:50
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Re: Duration

Post by Nerdllama » January 20th, 2011, 2:53 pm

It might depend on what type of rubber you are using... Are using Tan rubber? Another thing I found was that I was able to get more turns into thicker rubber with my 5:1 winder versus my 16:1 winder.
I am using tan rubber. It is 0.125" wide FAI tan super sport rubber, according to the online store that I bought it from. I could try winding with my friend's 10:1 winder, and see where that gets me.
At an Invitational we saw times between 1:30 and 1:55 in a 20 - 25 ft gym. What times have anybody else seen this year?
I got 30-50 seconds in practice flights in the Union CC regionals in New Jersey, but that ceiling was very bad, and then we got extremely unlucky with two broken helicopters in the eight minutes (30 seconds practice, 9 s official, and 13s official). I think first place in division C got about 1:12, or perhaps up to 15 seconds higher, but they just went all out and put 900 winds on, with no regard for the ceiling, and got extremely lucky when they dodged the rafters on the way up.

I think that the ceiling will greatly affect the flight times of those who can get over 20 seconds normally, because those helicopters will be the ones that don't just go up and come right back down again. If you have a bad ceiling (for example, at Union CC, the rafters on the ceiling were about 5 feet apart, and there were also hanging ropes, which made it even more difficult), you'll have to significantly lower your launch torque to avoid the rafters, unless you feel like risking your helicopter. If you have a good ceiling, the helicopters can all fly as they want, and the truly best one, not just the luckiest, will win.
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Re: Duration

Post by aubrey048 » January 25th, 2011, 9:30 am

Where do you get these winders??

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Re: Duration

Post by jander14indoor » January 25th, 2011, 11:38 am

The good yellow winders made by Knight & Pridham are available at most better on-line hobby suppliers who support free flight. Specifically I know A2Zcorp does at http://www.a2zcorp.us/store/ carries them. Also FAI Model Supply at www.faimodelsupply.com. Also good local hobby stores that carry freeflight stuff often carry these.

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Re: Duration

Post by aubrey048 » January 25th, 2011, 11:44 am

Thanks a million, Mr. Anderson!
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Re: Duration

Post by lllazar » January 25th, 2011, 2:43 pm

I've always wondered but never gotten to testing, but could a copter that instead of a second rotor, has something like....well its hard to explain in words, but basically picture your motor stick. Now lay a cross piece right at the middle of your motor stick, make it about as long as your rotor. Glue it down, making sure its 20 cm on each side. Then, creating half of a circle, place mylar/w.e material you use, on the cross piece and glue it down. Make sure the arc of the circle is pointing down, and glue the other "edge" to the bottom of your motor stick.

So basically u have a rotor at the top and that^ acting as a "second rotor of sorts. This would work fine for balancing the flight of the copter and it would also allow it to glide down more smoothly, what do you guys think?
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