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View Poll Results: OK, Place your bets for fun. WILL SHE FLY?
"The force is strong with this one." 195 54.62%
"She may not look like much, but she's got it where it counts" 101 28.29%
"Negitive.... It just impacted on the surface" 24 6.72%
Pull up! Pull up!! Ba-da-boommmm! 37 10.36%
Voters: 357. You may not vote on this poll

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Old May 05, 2005, 02:22 AM
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Australia, NSW, Mona Vale
Joined May 2002
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GO-RC.

Have you thought of putting a clear plastic horizontal fin on each side, with some dihedral in them to reduce the tendancyto Dutch Roll. Here is another Star Wars vehicle, and it has a tendancy to dutch roll too---if you let the speed get too low.





Cheers. Patrick.
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Old May 05, 2005, 02:46 AM
AllAloneInSpaceAndTime
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Sorry, dumb question alert. "Dutch Roll"? What exactly happens here? I know what a Dutch Oven is.... LOL
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Old May 05, 2005, 07:41 AM
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A DUTCH ROLL is when the plane oscillates from side to side about the rolling axis. Typical in models with too much dihedral or in acutely swept Deltas.
A model Millenium Falcon would qualify. Anything to damp the oscillations would help. Such as winglets.

Cheers. Patrick.
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Old May 05, 2005, 10:52 AM
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Scotland
Joined Jan 2003
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Well guys................. I get 1hr for lunch, and I've jsut spent 2hrs reading this thread.

Brilliant.

Snake2 and Go-Rc; well done.

Totally blown away that she flew and looked soooo good in the air. I really thought you'd blown the looks with the prop on the front, but you don't see it.

I voted; the force is strong, before i read the thread and it turns out i was right.

Well done.
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Old May 05, 2005, 11:44 AM
Balsadust Everywhere!!!!
Concepcion, Chile
Joined Jan 2005
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I'd still like to see a video of the Falcon.....
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Old May 05, 2005, 01:37 PM
PROFESSOR TRUTH JIMMY ICE
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United States, CA, Los Angeles
Joined Sep 2003
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Quote:
Originally Posted by oldpilot
GO-RC.

Have you thought of putting a clear plastic horizontal fin on each side, with some dihedral in them to reduce the tendancyto Dutch Roll. Here is another Star Wars vehicle, and it has a tendancy to dutch roll too---if you let the speed get too low.
Cheers. Patrick.
It would probably REALLY roll if you had the hyperspace ring around it
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Old May 05, 2005, 01:39 PM
PROFESSOR TRUTH JIMMY ICE
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United States, CA, Los Angeles
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How about this one for the next ship...

it's Obi-Wan's starfighter from Revenge of the Sith..... Ducted fan...mmm
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Old May 05, 2005, 02:03 PM
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Ireland, Kildare, Leixlip
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Quote:
Originally Posted by oldpilot
A DUTCH ROLL is when the plane oscillates from side to side about the rolling axis. Typical in models with too much dihedral or in acutely swept Deltas.
A model Millenium Falcon would qualify. Anything to damp the oscillations would help. Such as winglets.

Cheers. Patrick.
That's not actually quite accurate.

Dutch roll is a complex coupled mode in both roll and yaw caused by sideslip perturbance. It's not a simple rocking about the roll axis.
The magnitude of the roll and yaw components vary depending on the damping and inertia about each axis. If you look out at the wingtip of full a size plane with roughly equal roll and yaw components in dutch roll you'll see the wingtip describing a circular path. This turns into an ellipse either flat or tall and narrow depending on properties of the design. Delta will usually have dominant roll and say a high aspect ratio glider would normally have dominant yaw.
The yaw and roll responses are always out of phase as shown in the plotted model of a dutch roll time history below. The values in the plot correspond to a C5-A Galaxy (at least they do if I did it right!)

Aidan

P.S.
The name "Dutch roll" is due to someone describing the motion as being reminiscent of a dutch ice skater on a frozen river or something like that.
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Old May 05, 2005, 04:08 PM
Outcast outlaw
As far away from RCGroups and the AMA as possible!
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Uhhh -- yeah, sure... I understood all that...

...and that's why I didn't major in aeronautical engineering!
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Old May 05, 2005, 05:24 PM
www.toddsmodels.com
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Dutch Roll


Todd
www.toddsmodels.com
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Old May 05, 2005, 10:51 PM
AllAloneInSpaceAndTime
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I just think its funny that I can correct it. (Like on some of my Fan fold creations....) But never knew what the term meant.

Todd, A picture IS worth a thousand words!

Aidan, I'm sure you're right. But I'm slow...

Patrick, Thanks.


BTW, Go-RC, I think Obi-Wan's Starfighter should be the next project. What do you say?

Corey
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Old May 05, 2005, 11:30 PM
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Yeah, the picture is MUCH more useful but I didn't have one handy, sorry!
I'm writing an aerodynaimcs report at the moment which is why I'm up at 04:30hrs so I'm sort of in technical language mode, feel free to filter out the stuff you don't need!

Aidan
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Old May 06, 2005, 01:42 AM
↓↘→ + (punch)
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central PA.
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There's a spiffy pic of Obi's starfighter on walmart's site...



...very flyable really.
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Old May 06, 2005, 05:14 AM
DHC-2 Takitty desu
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Western Seaboard:Australia
Joined Jan 2005
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The A Wing has twin rudders at the aft of the ship, maybe that would be a better model?

Are there planes or a contstruction thread on the Jedi Starfighter? What was it made from etc?
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Old May 06, 2005, 05:53 AM
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Australia, NSW, Mona Vale
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THATS OBI WANs spiffy new Star Fighter from Revenge of the Sith.

The one I made is his earlier one.

Flys exceptionally well but could be made lighter. I used K & P Microjets on mine but I think the newer GWS 40 DF would be lighter (and cheaper), plus it can handle higher voltages. That means you can use 3S Li Polys more safely. See:-
http://www.rcgroups.com/links/index.php?id=4827 click on small pic for details.
and
"Jet Design Contest. Jedi Star Fighter." ----in rcgroups.

Cheers. Patrick.
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