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Old Jan 12, 2007, 11:22 PM
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GyroStick Better Flight Video

Here is the GyroStick Twin curently under construction. I decided to build this one because it will be easier to build and fly than the single and still keeps the same fun look. The single was really just to test the single rotor design I've been working on.

All I have left to do is make the two rotors which I should be able to do tomorrow. The blades will keep the same styling to match the Slow Stick as I used on the single. These are going to be 3 bladed rotors with fixed pitch, kinda like a Whopper rotor.

The single is still under development. Way more building time than testing time now with the short days and bad weather.

Dan
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Old Jan 13, 2007, 06:41 AM
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Got up way too early today so I got busy and made the blades. I had traced the blade patterns onto 3mm depron and then I painted the depron sheet last night. The pen marks show through the paint. This morning I cut them out and glued on the spars.

Next I need to make the rotor hubs. This is always the hardest part for me to do well.

Dan
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Old Jan 13, 2007, 03:56 PM
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Ready for maiden

The GyroStick Twin is ready for it's madien flight!

The blades were set to -8 degrees (thanks Al) and the disks are tilted back at 12 degrees. The disk diameter is 24".

AUW = 450 g.

It might be Tuesday before the weather is good enough for flying; I can't wait.

Dan
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Old Jan 13, 2007, 04:16 PM
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Dan,

She looks good. Do the rotors spin up OK if you hold the gyro horizontally ( like in a 90 degree bank) and you spin around on your feet a couple of turns? This will give a very crude feel of the lifting power of the rotors.

Hope you get it airborne sooner, and good luck when you fly it - Snoopy knows what is required .

Al
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Old Jan 13, 2007, 04:31 PM
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Quote:
Originally Posted by alfoot
Dan,

She looks good. Do the rotors spin up OK if you hold the gyro horizontally ( like in a 90 degree bank) and you spin around on your feet a couple of turns? This will give a very crude feel of the lifting power of the rotors.

Hope you get it airborne sooner, and good luck when you fly it - Snoopy knows what is required .

Al
They spin up very well, even just taxiing a short distance in my basement starts the rotors spinning pretty easily. Seems to be plenty of lift when I walk the model as you suggested.

It's good to have a pilot on board. If it crashes I can blame him.

Dan
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Old Jan 13, 2007, 06:44 PM
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Dan,
Looks like you have a winner on your hands!!!! VERY impressive! I like it very much. Please give us a flight report.

Dave
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Old Jan 13, 2007, 08:06 PM
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Dan,
Looks like you have a winner on your hands!!!! VERY impressive! I like it very much. Please give us a flight report.

Dave
Thanks.

I wanted to create something with a kind of fun, cartoon feel to it. I also wanted it easy to build and fly. It actually builds very easy except the rotor hub. It requires a bit more precision/patience than the rest. I would love to figure out a very simple way to make a decent hub to accomodate the three blades of this type.

Flight as soon as possible. Video as soon as it is warm enough for my wife to stand outside and shoot the footage...could be a while.


Dan
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Old Jan 13, 2007, 09:06 PM
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Why not use four blades and and stack the leading edge on the next one trailing edge which will give you your negative pitch for autorotation. Then you wont have to drill anything.

Dave
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Old Jan 13, 2007, 10:38 PM
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LF- why dont you just make a delta head out of 1/16 ply or CF or butter dish lid and shim some negative in and bolt the blades onto it.

I will find a pdf and post.

Doug
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Last edited by dougmontgomery; Jan 13, 2007 at 10:41 PM. Reason: add pdf
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Old Jan 15, 2007, 05:56 AM
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Pilot graphics

Here are the graphics I used for the pilot. Just print out the word document on a color printer. Glue the two sides two 3mm depron and cut out. The colors from my printer were'nt real vibrant so I used color markers to make it look a bit better.

In this format you can click each drawing and change the scale to suit...just do both by the same amount

Dan
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Old Jan 16, 2007, 11:25 AM
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Maiden flight

It is beautiful today but very cold. Just a breath of wind and 20F, sunny skies.

First flight, no taxiing around, I just went for it. The rotors spun up very quickly, lift off very smooth. Controls all worked very well. The only thing was it was nose heavy and slowly descended. I almost made a full circuit when I landed softly in the snow.

I noticed that the elevator trim on the Tx had been bumped and was set nose down.

Second flight, with Tx pitch trim adjusted to neutral, took off easy agian, easy to fly again, but still nose heavy. I was able to complete the circuit and land back at the covered concrete pad.

I moved the battery back a ways. 1100 mAh, 3s.

Third flight; easy take off, easy controls; still a bit nose heavy, but I could climb under full power and fly level at three quarters throttle. Yahoo!! I did a flyby and then at about two thirds of the way around on my second circuit one of the blades came off To my pleasant surprise I was able to hold it level and come in for a nice landing in the snow, whewww. I think it helped having a pilot on board. Nothing broken, I just have to reglue the blade back on.

The picture below sums up the pilots initial impression of this machine.

Dan
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Last edited by leadfeather; Jan 16, 2007 at 11:46 AM.
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Old Jan 16, 2007, 11:45 AM
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Dan,

I knew Snoopy would do it for you . Great news. Even at the low revs these rotors go round, I guess the forces are quite large, but it is nice to know that you can lose a blade without catastrophe. I once had 2 blades of 4 come off on one rotor of my i/c powered DB side-by-side Autogyro (not symmetrically either), and one from the other rotor as a result of the vibration, and that one got back OK too.

Where did you put the C of G?

Looking forward to more reports of the next flights,

Al
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Old Jan 16, 2007, 11:55 AM
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Al,

The cg was initially in line with the spindles. With the battery moved it is about an inch behind the spindles.

My gut feeing is that the blades have a bit too much negative incidence and aren't lifting as much as they should. I've been contemplating a fairly easy to build hub design for this style of blades that will let me ground adjust the blade incidence.

Dan
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Old Jan 16, 2007, 12:11 PM
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Dan,

That's about the same C of G as the Twirl plan, and that was on the conservative side for the mag article. It might be worth trying again at progressively more aft C of G if you can before changing the blade angle.

I've made 3 blade rotors using an equilateral triangle of balsa in the middle and overlapping the blades at the desired angle a la Twirl technique. It gives a bit more glueing area than you have. The size and thickness of the balsa triangle control the amount of blade overlap and hence the angle.

Al
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Old Jan 16, 2007, 12:54 PM
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Dan,
congratulations! Hmm, there's an old Slowstick standing in the corner of my workshop and i have a few spare Whopper rotors lying around...
Stephan
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