I agree about using stiff wood. One of the major problems I've had is breaking something on the copter every time it hits something. Worst case is hitting something like the ground at full torque. The kid I'm helping built one of the Freedom Flight kits. We'll see how it goes tonight. Dave recommends using a gram of 1/8" rubber with a spacer to keep the rubber low on the motorstick. My own design copter has done well with a 9" 1.5g motor with 10" hook spacing on an 18" motorstick.
----- Original Message -----
From: Bill Carney
To: Indoor_Construction_at_yahoogroups.com
Sent: Friday, February 18, 2011 7:11 AM
Subject: Re: [Indoor_Construction] Re: Science Olympiad Helicopter
Roy,
There is also a plan in the files section under Indoor Plans, named River City Rocket, Science Olypiad Helicopter. Build a few. I'd love to hear some more feedback.
If the thing is built with 6-7 lb wood it will come out right at 4 grams which was my intent. Taking full advantage of the minimum weight to design a model the average high school kid kid build without destroying in the process. I have had all my kids cover them with tissue as it's more readily available and less intimidating for kids and coaches. Typical flight times are about a minute and a half with a best flight so far of 1:56 which is very competitive from what I've seen so far.
The fast climb Art mentions is intentional as well. I have been coaching our kids to aim for an open spot between the girders (as very few of these competitions will take place in smooth ceiling venues) and the fast climb allows the heli to get to that spot before it drifts off into a girder(Usually!).
Flying with the 3/16th motor turned out to be the set up that delivered the highest times for us. On 1/8th they were coming down with a few hundred winds left AND had lower duration flights. I've tried some .140 sized motors but still did better with 3/16th.
Whirly Bill
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From: Roy White <roytigerwhite_at_yahoo.com>
To: Indoor_Construction_at_yahoogroups.com
Sent: Thu, February 17, 2011 10:34:36 PM
Subject: Re: [Indoor_Construction] Re: Science Olympiad Helicopter
THANK BILL Roy
------------------------------------------------------------------------------
From: Bill Carney <wcarneyjx_at_bellsouth.net>
To: Indoor_Construction_at_yahoogroups.com
Sent: Thu, February 17, 2011 1:57:38 PM
Subject: Re: [Indoor_Construction] Re: Science Olympiad Helicopter
Roy,
There are pics posted here in the 2011 Science Olympiad Helicopters Folder. It's the red and blue one and here's a video link:
http://www.youtube.com/watch?v=lqV_y-CSznM
Bill Carney
------------------------------------------------------------------------------
From: Roy White <roytigerwhite_at_yahoo.com>
To: Indoor_Construction_at_yahoogroups.com
Sent: Thu, February 17, 2011 2:26:10 PM
Subject: Re: [Indoor_Construction] Re: Science Olympiad Helicopter
sure would like to see a picture of your helicopter. Roy White
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From: art <aholt11552_at_bellsouth.net>
To: Indoor_Construction_at_yahoogroups.com
Sent: Thu, February 17, 2011 12:01:00 PM
Subject: [Indoor_Construction] Re: Science Olympiad Helicopter
Hi, group...
This is my first posting.
I just finished my River City Rocket, a little on the heavy side, but that's just me. My first timed flight, under a 13 foot ceiling, was 1:11 on about 375 turns.
The first posted plan showed a 40 cm motor stick and I had to run to the craft store to get a stout enough log to keep it from bending under the specified 8" loop of 3/16. When he revised the stick to 12" I just chopped 3.75 off one end and then slimmed the stick down a bit. The wood in the kits will be more carefully selected.
The great thing about the machine isn't so much the rocketlike climb, reflected in the name, but the stability. It can be upset, flip inverted, an as long as it has some rubber left it'll right itself and climb back up for more. Baffles me how it does that.
Art.
Received on Fri Feb 18 2011 - 06:19:51 CET