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Old Jun 20, 2010, 03:31 PM
JWs are Shear Fun!
Aerogance's Avatar
USA
Joined Sep 2008
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The DC60-Tail-equpped JW has had a few flights so far and the tail works fantastic. The JW was pretty beat up and noisy but with the new tail she is surprisingly quiet and fast. I hope to get radar verification later today.
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Old Jun 23, 2010, 08:05 PM
JWs are Shear Fun!
Aerogance's Avatar
USA
Joined Sep 2008
2,652 Posts
Got a radar reading of 135mph with the DC60 tail but my JW had major CG issues pop in the stronger wind. I just couldn't hold a good line with the tucking and gave up worrying about it since the tests were successful.
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Old Jun 23, 2010, 08:06 PM
JWs are Shear Fun!
Aerogance's Avatar
USA
Joined Sep 2008
2,652 Posts
I received word today that the DC60 fuse plug is delayed another week until the shop finishes a large job ahead of the plug turning. Shouldn't be much longer now!
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Old Jun 24, 2010, 10:31 PM
JWs are Shear Fun!
Aerogance's Avatar
USA
Joined Sep 2008
2,652 Posts
Full-size freeflight mockup testing completed

I made a full-size mockup of the DC60 and performed several test flights to establish a starting CG range. The plane flew very well, was very stable and didn't seem to mind the slow speeds or light wing loading.
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Old Jun 24, 2010, 10:33 PM
JWs are Shear Fun!
Aerogance's Avatar
USA
Joined Sep 2008
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Testflight Video

Here is video of one of the freeflight tests:

http://www.youtube.com/watch?v=mHBzGk2-IWk
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Old Jun 24, 2010, 10:39 PM
JWs are Shear Fun!
Aerogance's Avatar
USA
Joined Sep 2008
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Another test flight of the freeflight prototype:

http://www.youtube.com/watch?v=UiR91J4NJxI
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Old Jun 25, 2010, 10:55 PM
JWs are Shear Fun!
Aerogance's Avatar
USA
Joined Sep 2008
2,652 Posts
Radio Install

I started installing the radio in the lightweight prototype. I plan to fly it at a local hill in our horrendously light conditions we get. The goal is to explore CG range further and gain some insight into aileron sizing. Ailerons are cut and hinged. Linkages need to be installed and elevator installed, then she is ready for flight.

As planned, the wing is thick toward the tips. After cutting the holes for the servos, there was still 1/4" of core material left. Considering these wings are just cores and don't have the added thickness of glass yet, it should be very easy to locate full size servos at the outboard positions of the final wing. I would not expect flutter issues with the final model.
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Old Jun 26, 2010, 07:18 PM
JWs are Shear Fun!
Aerogance's Avatar
USA
Joined Sep 2008
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Radio install completed

Finished the radio install in the lightweight prototype DC60 today. It is 3 channels (2 ailerons, 1 elevator). Flaps are not required on this light of a model.
http://www.youtube.com/watch?v=kn8aBofqypI
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Old Jun 26, 2010, 10:30 PM
JWs are Shear Fun!
Aerogance's Avatar
USA
Joined Sep 2008
2,652 Posts
Daisy Cutter 60 Maiden Flight!

I took the prototype DC60 to my local hill and did a long maiden flight. Everything went smooth and she flew like a dream. I even took a chance and DS'd a few laps on the maiden. I did several flights after and spent some time DS'ing the light plane in the rough conditions. Here is video from the maiden flight:

http://www.youtube.com/watch?v=JAei3O5G1lE
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Old Jun 26, 2010, 10:34 PM
JWs are Shear Fun!
Aerogance's Avatar
USA
Joined Sep 2008
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DC60 prototype first DS laps!

Here is video from the maiden flight where the wind came up enough for me to get enough initial height to dive in. The plane has no spar and is uncovered 60psi blue foam. The only reinforcement to the wing is one 3/4-span strip of extreme tape top and bottom. I was worried about pulling more than 3g's so I took it easy on the first laps. In later flights I dug deep a few times and got alot of speed but the wing was bending and near failure. Regardless, the plane liked the extra speed and I can't wait to get the real one done so I can take her to Weldon in some real wind:

http://www.youtube.com/watch?v=oqdNQXRW5XQ
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Last edited by Aerogance; Sep 25, 2010 at 02:14 AM.
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Old Jun 26, 2010, 10:36 PM
JWs are Shear Fun!
Aerogance's Avatar
USA
Joined Sep 2008
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DC60 more DS

Here is another clip of some "safe" DS laps. It was bumpy and the wind was light, but the plane managed to eat up the bumps and hold energy for a few laps. The only clean air was right at bush level so I kept her in one piece by flying further out. This had the benefit of limiting speed so I didn't have any issues with flutter or wing failure:

http://www.youtube.com/watch?v=Jn3QPQo9bQw
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Old Jun 26, 2010, 10:59 PM
JWs are Shear Fun!
Aerogance's Avatar
USA
Joined Sep 2008
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Test flight summary

I learned alot today from the maiden and subsequent flights.

I wanted the Daisy Cutter to have a distinctive look, and watching her fly you can see she looks like nothing else in the sky. The final fuselage will further distinguish the plane from other models. The point of the project is put some fresh ideas in the sky, and I was happy to see her looking like her own in the air.

I deliberately undersized the ailerons so I would have a point of reference when I make them full size on the first moulded model.

I made the elevator a shorter percent of chord than I intend to use so I would have a reference for when I make it full size on the real model.

I tested for deep stall, but only noticed slight effects at extreme slow speed (no flaps installed). The effect was very minor pitch-up but elevator authority remained. The plane doesn't like to fly just over stall so this would only be an issue if you deliberately fly slow with an aft CG like I flew today. Moving the CG slightly forward of the extreme aft setting would likely erase any ill effects altogether. I will test this next time around.

The airfoil works at low speeds, but needs alot more wing loading than the prototype could offer. Nosing forward slightly and getting the AOA a little shallower allowed the speed to pick up and the airfoil's performance to really kick in. In a few of the DS tests where I dug deep and got her moving way too fast for the build, the plane felt beautiful.

The planform incorporates a very long tail moment. The vertical stab does a great job of stabilizing the ship. The only tail wag I saw was when I was just above stall and would pull full-elevator. The wing wash would appear to diminish the vertical tail's tracking a little bit. At any normal to high speed runs, this effect didn't occur. This is good.

The supercritical tail felt just as good any other tail I can remember. My elevator was reduced in chord by 20% from what I plan for the first model, and I noticed that I needed more up elevator than you typically apply for a typical model. The final elevator size should be perfect.

The ailerons were sufficient for flying and DS, but not big enough for low-speed aerobatics and were just a tad small to deal with any real emergency. The ailerons on the real model are to be 25% longer so they should be ideal for a fast DS ship. I was worried about the laminar flow airfoil "shadowing" the ailerons at low speed, but never once felt any diminished aileron authority (even during stall tests). The creators of the airfoil designed it to allow correct flow over the ailerons at all useable alpha and my flight tests today confirmed the design works. This was one of my biggest fears and I now have no concerns.

As side note, the new Spektrum module for my JR 9303 worked like a charm. I like the heavier feel of the JR to the DX7 and highly recommend the new module to anyone still on the fence like I was.

I am still a week to a week and half out on the fuselage plug. Once I get the plug, I will be able to make substantial progress on the final model.
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Last edited by Aerogance; Jun 26, 2010 at 11:22 PM.
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Old Jun 27, 2010, 01:39 PM
Just Fly it
USA, CA, Bakersfield
Joined Jul 2006
2,034 Posts
Congratulations Aaron

This must be satisfying to see your plane actually fly. Great pictures and with an iPhone camera! maybe i dont need anything more than i have. (iphone)
John
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Old Jun 27, 2010, 01:48 PM
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HB cali
Joined Apr 2006
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Quote:
Originally Posted by Aerogance View Post
Here is another clip of some "safe" DS laps. It was bumpy and the wind was light, but the plane managed to eat up the bumps and hold energy for a few laps. The only clean air was right at bush level so I kept her in one piece by flying further out. This had the benefit of limiting speed so I didn't have any issues with flutter or wing failure:

http://www.youtube.com/watch?v=Jn3QPQo9bQw
how cool is that?

Nice Job Aaron...
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Old Jun 29, 2010, 12:20 AM
JWs are Shear Fun!
Aerogance's Avatar
USA
Joined Sep 2008
2,652 Posts
CG Testing complete

I made some changes to the prototype:

1. I added a 48" long 1/2" diameter aluminum spar.
2. I moved the CG forward 1/4".

The extra weight didn't affect the light wind ability of the plane. If anything, it liked flying faster. I could slow it to a near-hover in 12mph wind.

The CG, however, made a nice improvement to both cruising speed and overall stability. The plane liked to fly faster and as a result would respond better to lift. I tested a couple of CG positions and settled on the one I liked best. This will be the starting CG for the first model.

I made a video describing the construction of the prototype. This is one of the crudest models I have ever built, but it is serving its purpose as a low-speed test platform. If you have some basic foam cutting skills, some spare radio components and about 20 bucks, you can build something like this:

http://www.youtube.com/watch?v=Bg9n0nZN68g
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