Gee Bee QED

[Mr NCT]

This is my first attempt at anything close to a Flite Test master series design so I picked a manufacturer and a plane that were notorious for spectacular crashes.
From Wikipedia:
"The Granville Gee Bee R-6 International Super Sportster, named "Q.E.D." (latin: quod erat demonstrandum "it is proven"), and later named "Conquistador del Cielo" (Spanish: "sky conqueror"), was the last in a series of racing and touring monoplane aircraft from the Granville Brothers. The R-6H was dogged with bad luck throughout its career and never finished any race it entered."

I'm shooting for a 40" wingspan C pack flier. Here's the Fusion 360 rendering:

And now the build:


I wasn't planning on the prototype being flyable but once it was together.... Why not?


I'm expecting the QED to meet it's fate just like the real one. Looking at the plane from the front the tail is twisted slightly CW and the rear fuselage bows just a little to port. Will it fly? I'm expecting a spectacular crash!
Place your bets now before watching the video.

 

[Mr NCT]

The cowl is fitted and the canopy is printing.

 

[luvmy40]

Very nice! and it looked like it was a joy to fly!

 

[Mr NCT]

Very nice! and it looked like it was a joy to fly!

I was very surprised. I was expecting a spectacular crash.

 

[jpot1]

Looks like it flew really well!

 

[Mr NCT]

The cowl and canopy made no difference in the battery placement for the CG - balanced each other out.



I have a friction fit on the cowl but it vibrated forward into the prop. Have to find a way to fix it in place without gluing. My biggest surprise is how well it flies - I haven't even had to adjust the trim settings.

 

[luvmy40]

The cowl and canopy made no difference in the battery placement for the CG - balanced each other out.

View attachment 231420

I have a friction fit on the cowl but it vibrated forward into the prop. Have to find a way to fix it in place without gluing. My biggest surprise is how well it flies - I haven't even had to adjust the trim settings.

Try coating the contact areas with rubber cement and letting it dry thoroughly before assembling.

 

[Mr NCT]

Try coating the contact areas with rubber cement and letting it dry thoroughly before assembling.

Will that release ok if I need to remove it?

 

[luvmy40]

If you let the adhesive all dry completely before assembling the pieces there should be no adhesion, only added friction.

 

[Kartman24]

Love GeeBees, nice job, look forward to seeing it finished, use small magnets to attach the cowl, that is what i use on cowls and battery hatches.

 

[Mr NCT]

I am about done with v2 and finalizing plans.

 

[danskis]

Awesome work and looking forward to plans. Just wondering do you have a needle cutter?

 

[Mr NCT]

Awesome work and looking forward to plans. Just wondering do you have a needle cutter?

No, wish I did. Trying to decide whether to go that way or a laser. @Ratcheeroo just got a table top laser and I'm waiting to see how his turns out.

 

[Piotrsko]

The GB series were noted to be mildly unstable with aileron reversal and welded in place flying wires... Since no one lived to provide that data until Delmar Benjamin, they couldn't fix the problem.

Model planes operate in a totally different environment, so I am not suprised it flew well

 

[Mr NCT]

The GB series were noted to be mildly unstable with aileron reversal and welded in place flying wires... Since no one lived to provide that data until Delmar Benjamin, they couldn't fix the problem.

That's a common myth. Not trying to be argumentative (just factual), but....
Pilots who flew the Gee Bee R series (1, 2 & 6) & lived to fly again:
Jimmy Doolittle
Roy Minor
Lee Gehlbach
Wesley Smith
Royal Leonard
Lee Miles
George Armisted
Jacqueline Cochran
Francisco Sarabia - who flew it many times but died in the QED because a rag was sucked into the carburetor on takeoff

 

[jpot1]

Plans ready?

 

[Mr NCT]

Just finishing the second build, not happy with the flats for the rear fuselage. 3D cowl is done and still working on cockpit/canopy. Be happy to send what I have.

 

[jpot1]

Just finishing the second build, not happy with the flats for the rear fuselage. 3D cowl is done and still working on cockpit/canopy. Be happy to send what I have.

All good, I’ll wait till it’s released.

 

[Tench745]

That's a common myth. Not trying to be argumentative (just factual), but....
Pilots who flew the Gee Bee R series (1, 2 & 6) & lived to fly again:
Jimmy Doolittle
Roy Minor
Lee Gehlbach
Wesley Smith
Royal Leonard
Lee Miles
George Armisted
Jacqueline Cochran
Francisco Sarabia - who flew it many times but died in the QED because a rag was sucked into the carburetor on takeoff

I think what Mr NCT was getting at is that, specifically those who experienced aileron reversal/flutter in a GeeBee did not live to tell others about the reversal/flutter. I don't think he was saying that all GeeBee pilots died in the aircraft.

 

[Mr NCT]

Finishing up version 2. I used the rollation method to get the back two skins with some success but still have some seams that are less than close. It will be interesting to see if the good flying characteristics of V1 follow through to V2 since the tail on V2 is straight and not twisted and bowed.
Thanks to @Whit Armstrong for his videos on using exactflat. V3 is about halfway done and I'm getting better seams with the new skins. They'll still need some filler but not as much.
Just finished rereading "A Legacy of Speed, The Gee Bee Racers" and Delmar Benjamin's book "Gee Bee". It is amazing how many different problems took the Z, R1, R2, and the R1/R2 Intestinal Fortitude out of races. Loose gas caps, cracked oil lines, locked up brakes on wet grass, a departure stall, and a couple of snap rolls during landing thought to be from aileron reversal. Delmar even had one of those when he tried a three point landing. He said from there on he flew approach at 160, touch down at 120 and kept the tail up until it was at a 'fast run'.