Big Gull Tribute
 

About 40 years ago I designed an antique, R/C tribute aircraft to Winnie Davis' "Big Gull" free flight design. It was different enough to have its own name, so I called it "Gulliver's Traveler" as a reminder of the aircraft that inspired it.

I framed it up over the course of many months back then, but then got involved through Don Lowe, Steve Rojecki and Tony F in pattern and TOC aircraft. Time flies, as they say, and the Traveler sat for years and years in an Ohio basement until 2012 and then in a North Carolina attic until about two weeks ago.

I have decided to finish it and have been piddling away at some small tasks while I wait for some materials and accessories that I had to order. Here's a photo of the most complete subassembly:


https://cimg8.ibsrv.net/gimg/www.rcu...aa09037397.jpg

I can post some progress photos, if there's any interest, but as a minimum, I will provide some finished product shots , eventually.

Ken

Great sanding job on the complex shape!

Here's a shot of the fuselage in its current state. I've just completed the the wing to fuselage fillets. And it's definitely a big time gull wing.


https://cimg1.ibsrv.net/gimg/www.rcu...e45934719d.jpg

Wow, the whole airplane is one complex shape! Very unusual and somehow "organic". Now I see why there are skids under the stab. The open-rocker engine matches this piece of art. :-)

The Brushfire fuselage, which is complex enough, must have been child's play for you.

With the wheel up front, will this model take-off from ground or has it to be hand-launched?

The outboard skids have plywood cores and steel wire at the bottom to act as the surface that touches the ground. The fuselage skid also has a plywood core and is designed for a 1 1/2 inch diameter tail wheel that will be half exposed. I think a grass field would be preferred for takeoff and landing.

Okay. I have it mostly sanded enough so that I'm not embarrassed to show you what the whole thing looks like. Sorry, but I couldn't get the dog to sit still next to it for a size reference.


https://cimg6.ibsrv.net/gimg/www.rcu...4da8f2f581.jpg


https://cimg2.ibsrv.net/gimg/www.rcu...55bdecbb95.jpg


https://cimg1.ibsrv.net/gimg/www.rcu...3d4c6074b6.jpg


https://cimg2.ibsrv.net/gimg/www.rcu...5a49fb2e93.jpg

Lot's of work to do before the covering process. I'll try to add update photos along the way.

Ken

It just occurred to me that I did give you a size reference. The driveway block it's sitting on is 11.5 ft by 9 ft. The 11.5 is in the downhill direction.

Stunning! How on earth did you build these wings? I imagine you made one jig for both and the enabling simplification was using a flat-bottom airfoil. And you didn't use CAD or laser-cutting, I suppose. Had the leading- and trailing-edge stock to be laminated to keep the curvature or is it all held by the main spars?

There are several size references: the engine, the garage, the perspective. Thanks for sharing!

You are correct that the flat bottom airfoil was the key. I built a full span work board out of 3/4 inch plywood. The curved areas of the actual building surface plywood were back sawn every 1/4 inch in the chord-wise direction to a depth that left only 1/8 inch of wood. Three full span plywood pieces to support the work surface and hold its curvature true were sawn to match the wing's front view and required no grooving. A 3/4 inch end piece kept kept the building board square.

It was built very conventionally in the flat area between the two curved sections. The spars, leading edges and trailing edges in the curved sections were laminated from 1/8 balsa. All that glue probably makes it a little stronger.

The inboard curvature where the wing halves slide onto the aluminum tongues had to be a true circular arc. I think it's clear why that has to be.

Thanks for your enthusiasm. Getting back to work on the beast has reminded me what a pain it is to work on it. And probably why I set it aside so many years ago.
But retirement gives me the freedom to set it aside whenever it starts to become a grind. It make take a while, but I will finish it.

That is beautiful. Stunning. Amazing.

Following!

Thanks, Popeye. You are too kind.

Seems like I've been carving and sanding for a month. But I've made some progress and the vertical fin is covered and the horizontal tail is partially covered. But it's still going to be quite a while before I can post a completed aircraft pic. It has also been very frustrating at times {uncooled workshop in 90+ weather), so I've had to set it aside now and then to keep my sanity.

Here's a shot of the completed empennage.


https://cimg3.ibsrv.net/gimg/www.rcu...9dbc7617ab.jpg

The MonoKote colors are transparent yellow and opaque maroon. The striping is from Sig and is silver. The wing will be very similar to the tail and the fuselage will be a similar theme with the maroon on the upper half.
Haven't decided whether to do the wing or fuse next. Both need extensive shaping and sanding before covering.

I'll post progress, but it will be awhile 'til the next photo.

Nice color scheme!

It's been a while, but I finally have a covered fuselage/tail photo to share. I've been remembering what I like and what drives me crazy about MonoKote.

The wings need additional carving and sanding and have been standing by while I tilted at compound curved fuselages. I've done some servo installation prep and given some thought to pushrod exits and the like.

I suspect covered wing photos will be a while because I've saved the worst of the compound curve MonoKote issues for last. On the plus side, I've been relearning as i go.


https://cimg9.ibsrv.net/gimg/www.rcu...494a862731.jpg

Thanks for your interest and patience.

Ken

Beautiful!

Looks immaculate.

Update: The left wing still lacks final carving and sanding. But the right wing is 75% MonoKoted!

I have one more maroon panel to iron on the top of the right wing. The combination of airfoil thickness changing with span and rib shortening as you advance from wing root to wing tip creates a bizarre situation in combination with the gull dihedral. The spars, from a top view, are all perfectly straight lines, but the full span MonoKote pieces that align with the edges of the front spar must be curved in one direction in the root area of the gull front view curvature and in the other direction near the tip where the gull wing curves up. In between, where the front view of the wing is a straight line, the corresponding MonoKote edge also has to be a straight line.

Even after achieving the correct "curve one way-/-straight-/-curve the other way" cut shape for the for the aft edge of the Monokote piece, you still have double curvature issues associated with the gull dihedral changes and the ribs shortening.

So I did the larger aft pieces of yellow first. It was fairly easy on the bottom, which is flat, but I did get a preview of future issues near the wingtip where the chord and the ribs got smaller very fast. On the top, I had to do some trim-as-you-go as I progressed from root to tip. It came out okay, but it wouldn't stand up well to a close inspection.

This morning I did the maroon on the bottom of the wing. Not bad at all thanks to the flat bottom airfoil. This evening comes the bigger challenge of the maroon on the top. I've mapped out and cut the maroon piece for the top leading edge area and it appears to result in a straight line at the back edge of the spar.

Time will tell. Wish me luck!

If it's not embarrassing, I'll post photo or two soon.

Unthinkable that something from you could be embarrassing, but good luck anyway! :-)

As promised: a couple photos of the completed right wing.


https://cimg7.ibsrv.net/gimg/www.rcu...d3c41f5809.jpg


https://cimg2.ibsrv.net/gimg/www.rcu...8b6035c843.jpg

It looks good and goes well with the rest of the color scheme, but it doesn't stand up too well to close inspection. Lots of little boo-boos and a few small wrinkles that wouldn't come out even with a blow torch.
For me, that's a pretty typical MonoKote job and I'm okay with it after all these years. On to the left wing!

Ken

I can't wait to see it assembled followed by an in flight video!

The wings are MonoKoted, striped and finally finished. And not a moment too soon. I was close to a sanity/insanity transition with all the double and triple curve issues.
There are still a lot of finishing tasks to accomplish, but the end is in sight.
For any of you hoping for inflight photos or video, I'm sorry to report that there won't be any. I don't have a modern R/C system, a flying field, nor insurance coverage. I am offering "Gulliver's Traveler" to the AMA Museum. If they accept it, great. If not, it will go back to the attic, but will hang fully assembled from the ceiling this time.
Ken

https://cimg9.ibsrv.net/gimg/www.rcu...89e17c99e6.jpg


https://cimg4.ibsrv.net/gimg/www.rcu...f68b466299.jpg

Ken, if they have half a brain they will!

They already have three model aircraft from me, so I'm hoping they'll take one more.

Which three?

- The Reed Falcon that won the 1984 TOC. The real one was designed by Dr. Maitland Reed of the University of Durban in South Africa. I was designer and builder of the model version. Don Chapman was the engine man. But Steve Rojecki as the pilot was why it won..
- The Overlord, a retractable gear pattern biplane I designed and built that never won anything because I flew it.
- A silk and dope pristine example of a Goldberg Comet Clipper that I built and flew in S.A.M. contests.
The Reed Falcon is on display. The other two may be in the archives and not displayed.