B1-B With Swing Wings and Lights

[Pieliker96]

top 10 photos taken moments before disaster



Seems my tail design wasn't up to the task of a high speed pass. After the elevator(s?) came off, The plane tucked under and pancaked inverted, leaving it surprisingly intact (the swing wings still work)



Still haven't gotten to swing the wings in flight. I'll probably end up building another one with the lessons learned from V1, as I want to tear down the existing airframe to see how it has fared.

 

[L Edge]

top 10 photos taken moments before disaster

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Seems my tail design wasn't up to the task of a high speed pass. After the elevator(s?) came off, The plane tucked under and pancaked inverted, leaving it surprisingly intact (the swing wings still work)

View attachment 153781

Still haven't gotten to swing the wings in flight. I'll probably end up building another one with the lessons learned from V1, as I want to tear down the existing airframe to see how it has fared.

Hope you do, you gave me the effort to put back together my forward to aft swing wing by replacing my sheared servoes(now stronger) to see a full flight from takeoff to landing.

 

[Pieliker96]

Hope you do, you gave me the effort to put back together my forward to aft swing wing by replacing my sheared servoes(now stronger) to see a full flight from takeoff to landing.

Best of luck man! Fly safe.

 

[Pieliker96]

Here's what went wrong: The inboard servo horn unglued itself from the foam. It was retained by the linkage stopper, but the rest of the control surface was not and ended up falling off due to aerodynamic forces. The center of pressure shifted forwards, making the craft effectively tail heavy. Downwards pitch divergence ensued, with the plane nearly completing a half loop upon pancaking inverted into the ground. The fuselage broke at the tail, the vertical stabilizer crushed, and the firewall, motor, and prop were forcibly ejected from the craft, possibly further mangling the tail in the process.



Ultimately, this is an example of a single-point failure leading to loss of controlled flight. Here's some improvements that would eliminate this:

-Move linkage stopper to the end of the outer servo horn so the tailplane would still be retained in the event of this failure mode
-Attach both horns more securly to the control surface, likely with embedded pushrods
-Replace the skewer with an equivalent carbon fiber rod for a smaller chance of aeroelastic effects or flutter

 

[kinch]

In the spirit of procrastinating on existing projects by starting and finishing entirely new ones, I present the Bone!

It's around 1.4kg when all is said and done, which is fairly heavy for its wing area (Cube loading is ~7). I'm hoping to hand-launch this, somehow. It's powered by Power Pack C on a 2250 4s, which should give it a TWR of around 1:1. It'll maiden on a 9x6 prop, although I have some 9x9s if I want to try for speed.

Here's some pictures of development:

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Lighting control board, burners, and burner testing

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Reasonably skookum spar and wing swing-y bits, using the Actuonix L12-R actuator with a 100mm stroke.

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Starting to look like something!

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All-moving elevator (not swung) / elevons (swung) setup, using control horns. Note the wheel collars which keep everything in place.

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All done! Certainly a bit messy in spots. Will require sanding and a coat of paint at some point, but now is not the time.

Maiden flight soon™.

very cool