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mi-nan

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I seen a monocopter on the web recently and it got me thinking. I have a set of r/c helicopter wood blades. Would one of them work for a monocopter? Here are a couple of pictures of the finished project just before launch. I flew it on a G-33. I didn't account for the centrifugal force on the motor tossing the case when I friction fitted the motor. I found the case and I plan on trying again. The second tube houses a parachute.

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Lentamental

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Looks good. My only question is why use a parachute? The whole point of the design is that it inherently helicopters, so doesn't need a separate recovery system.


As for monocopters, I have had some very mixed results. My first one, copied straight out of the NAR handbook a few years back, absolutely sucked. It went up 10', and over 20', nearly hitting the people loading their rockets on the next set of pads. I then took that design and totally rebuilt it, building up an aerofoil around some central struts, streamlining the nosecone, cutting down the weight by 30%, and generally making the whole thing much more aerodynamic. The result was spectacular, flying up at least 100'. However, when I went back to launch it again this past month, after 5-7 years of sitting in my closet, it did not fare so well. it took off at a pretty serious angle, flying right over the crowd, and falling to the ground with several seconds still on the ejection charge. It landed pointing the engine straight at a small child :y: luckily when it spit the engine it missed...

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mi-nan

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The bigger monocopters I have seen on video fall out of the sky like a stone when they stop spinning. The don't really auto rotate so I used a parachute to help slow its decent.
 

troj

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The bigger monocopters I have seen on video fall out of the sky like a stone when they stop spinning. The don't really auto rotate so I used a parachute to help slow its decent.
I think it depends a lot on the design of the monocoptor, as well as the materials they're made of.

Ed Miller sells a monocoptor kit that does one of two things -- sometimes it auto-rotates back down, and sometimes it flutters back. Either way, it recovers safely without a parachute.

But, it has a good-sized "wing" that's made purely of light balsa. Your helicoptor blade is likely a lot more dense, in addition to not being large enough to generate much drag on the way down, so the parachute is a good idea.

-Kevin
 

JAL3

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The bigger monocopters I have seen on video fall out of the sky like a stone when they stop spinning. The don't really auto rotate so I used a parachute to help slow its decent.
A guy in my club, Ken Kryzak, is a monocopter enthusiast. His usually autorotate or flutter down. Some of his more recent designs use changing pitch to accomplish the autorotation.

This is one of his older ones on a G33. It had about a 5 foot span and fluttered down: http://www.flickr.com/photos/23694991@N03/2953710058/

A more recent effort used a cam to change the pitch. an explanation of it is here: http://www.flickr.com/photos/23694991@N03/3957063377/in/set-72157608222928932/

I really like this last one but the pin sheared on takeoff making for an exciting time. :y:
 

rstaff3

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You must have built it strong. My experience with a G-powered monocopter, despite epoxy and carbon straps, resulted in re-kitting. Good job.

I agree that a chute shouldn't be required. However, I've built and watched a lot of them and very few actually autorotate back down. My philosophy in rocketry says that, just because you don't need something doesn't mean, you don't want it :)

PS - Anybody wanting to get into monos should take a look at Art Applewhite's products.
 

JAL3

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PS - Anybody wanting to get into monos should take a look at Art Applewhite's products.
I'll second that! His Helix line is very simple but works well. Then he has some others as well including plans for an MMX version.
 

kramer714

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http://www.youtube.com/watch?v=qiLpPQXSO7g

The will continue to fly if you have a good balance weight on them. Mine flies from a G and keeps spinning all the way to the ground, graphite airfoil, graphite counter balance and fiberglass motor tube.

I think an RC blade would work well!
 
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JAL3

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http://www.youtube.com/watch?v=qiLpPQX

The will continue to fly if you have a good balance weight on them. Mine flies from a G and keeps spinning all the way to the ground, graphite airfoil, graphite counter balance and fiberglass motor tube.

I think an RC blade would work well!
Clciking the link is giving a "malformed Video ID error" from YouTube.:confused2:
 

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