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Jan 27, 2019, 05:33 PM
AndyKunz's Avatar
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Build Log

2m/80" B-36


Let me start by saying I appreciate feedback, comments, and suggestions for improvements. This plane is a little out of my norm, so if I do something stupid please let me know before I make a total fool of myself!

Also, this isn't a "true scale" model to the extent of many of the planes in this forum. It's more like a 2m electric glider that is very draggy, but that looks a lot like a B-36.


The B-36 is one of those planes that everybody loves to see simply because they are so rare. Though they served as front-line warriors for a decade, they never once dropped a bomb on an enemy nor fired a gun in self-defense.

This B-36 project started in earnest for me after my middle son, Ian, prodded and prodded. After some time I started doing some research to find what was available. Very little, it turns out! I found a set of plans on Outerzone (#2778, designed by John Considine RCGroups username “Boomerang1”), also available printed on eBay by “mrhobby”. I didn't want one that big – I have a rule that all my planes have to fit into my van assembled, and there's no way a 12' monster will do that. While talking about this with my friends, Michael Ramsey mentioned that Flying Models published a B-36 by Dave Rees when he worked there. What he didn't mention was that it was his first issue for FM, and he was the subject of the editorial, photograph and all.

Plans (CD003) and back issue (8/96) of Flying Models were ordered from the Flying Models Plans store www.store.flying-models.com. The 57” FM model would have only about 300 sq in of wing area, though, and my desire was to power it using SIX motors in the 180 (UMX) size. It would only take two of them to provide oodles of power at that scale, so I did a little more research. It turns out that a 2m glider is about 600 sq in, and is often launched with an .049 to .10 (I used .049's on my Drifter II and Gentle Lady as a kid), and that would be a more appropriate size for the power I had in mind.

The FM plans were instead used to get an outline for the CAD, which was scaled up by a factor of 1.4 (not quite the square root of 2), taking me to 587 sq in and 80” span – just a smidgen over 2 meters, and big enough to be an official Giant Scale. Using a cubic scaling factor, this would mean that it would be about 27 ounces based on the Rees free flight version. I'm not quite the nut for low weight so I figured I should be happy with a 40-45 ounce target. I'm not looking to thermal, after all, but I don't want it to zip around like a fighter either.

An 80" plane isn't going to fit fully assembled in my van, but with only bolting on the wing and three electrical connections, I felt it was worth the effort. Especially to have a B-36. How cool is that?! (Only 3 electrical connections? How so, Andy? ... )

The FM article was extremely well-written and detailed, leaving little need for construction photos, of which there were none. The text was very necessary, though, as the construction techniques he used for the fuselage were not at all familiar to me. I will be using pretty much the same technique for my plane.

The wings are rather standard construction for a 2m plane. I based mine on a combination of my old faithful Drifter II and Gentle Lady, with some new electronics for the multiple functions. Oh, did I not mention? This plane will have 6 channels per side, plus at least 5 in the fuselage. Good thing I'm using a Spektrum DX18 to control it!

Getting Started

I am still in the process of working out details for this plane, but with actually gluing things together today I felt like it was an OK time to start posting.

This is a bit of a research project as well, so I expect I will be revisiting a few things along the way. I already had to do that a few times for the wheels, motors, and custom electronics.

Construction of the wings is waiting on an order to come in of the trailing edge stock and spruce spar materials. That's good, because it means I can make progress by starting out on the one thing I hate with a passion -- nacelles.

The B-36 designers were kind to me. The nacelles are all pretty much the same for the first third and last third of the longest nacelle being close-enough to use for all three. It's just the center section that changes, so that's how I'll be making mine.

Construction began by starting on the nacelle plug. Rather than lots of templates which would be needed for a true-scale design, I cut a side view and traced it onto a block of medium balsa. I made 1/16" birch ply templates that were inserted into slots in the block, and then carved and sanded to shape.

Andy
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Jan 27, 2019, 08:31 PM
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glewis's Avatar
Cool! Signing in for this one.
I purchased the Rees plans quite a while back thinking I could squeeze GWS IPS or LPS gear drives in the wing. Nope, wouldn't fit...
Isn't this the one that used a roiled tube fuselage? You planning on using that method?
Glenn
Jan 27, 2019, 08:44 PM
AndyKunz's Avatar
Thread OP
Yes, the Rees one is the rolled balsa fuse. I'll be doing the same thing here. The difference is that I'm using 4" Schedule 40 PVC as the mold instead of a paper mailing tube.

You could use a set of micro drone motors now. Those motors he sold were pretty much the same thing. Pager motors and 3.5" props.

Andy
Jan 27, 2019, 09:54 PM
AndyKunz's Avatar
Thread OP
After the Titebond cured, I used the bandsaw to trim a bit of excess wood off the sides of the plug to get a head start on the taper. To make the cut true, I used the block that I had removed to shim the larger piece up. If I hadn't done this, the cut on the side would have been angled from what it should have been, and the changing angle would have made it hard to do safely.

After lots of carving and LOTS of sanding, first with a bar and then with flexible wall sanders, I have an almost-ready nacelle plug.

The ply templates in the block give an audible reference as the sanding gets closer. At first the gap fills with dust, and then the dust doesn't stay in it, and then it makes a different sound as I start to touch it with the sander.

Andy
Jan 27, 2019, 10:51 PM
Summit Model Aeronautics
Steve85's Avatar
Andy,

This is going to be really cool. Your technique of inserting ply templates into sawn slots is brilliant, and one I'm going to file away for future use.

Steve
Jan 28, 2019, 01:21 AM
Registered User
Wow! Six turning and four silent. Still, that's a cool model to build. I have a copy of an article from a plastic model magazine that described one of the B-36s being tested for how it would handle weather in minus 40 degrees in Alaska. So way back in 1950, a B-36B model took off for Alaska, with, get this a Mark IV Plutomium bomb (not armed). Long story made short, it made it to Alaska and was serviced while the engines were running. After three hours, full fuel and last-minute checks, it flew off bound for the States. It hit extremely had weather, with freezing rain, headwinds, hail and snow. Port observer in the rear of the fuselage reported that he saw a fifteen foot blue flame from the # 1 engine. Following procedures, the command pilot shut the engine down. Then another engine caught fire. They shut down that engine and started to decend. They reported to the Canada's controllers of their plight. The propeller on another engine went into overspeed indicating that the ice was building up along the leading edges of the wing and plugging up the intakes to the carberutors. They didn't have adequate carberutor heating or none existed at that time. The plane then flew in a westerly heading out to sea to drop the bomb and was seen to explode without the plutomium. Then they flew back towards the mainland and started to decend further and ultimately ended up slamming into the side of a mountain. Thus, starting the term: "Broken Arrow." to denote "....an accident or incident involving a nuclear device." The P&W-4360 were never designed to face backwards as on the B-36, making the carberuters face incoming freezing weather making them more susceptible to icing and overloading the fuel making the engines fire-prone. One final note, not commonly known was that the Secretary of Defense was a former executive of Convair and Secretary of the Air Force was also in cahoots with Convair which might helpto explain the scrapping of Northrop's all-wing bomber.

Good movie to watch is: Strategic Air Command staring Jimmy Stewart.
Last edited by Skyediamonds; Jan 28, 2019 at 01:24 AM. Reason: spelling
Jan 28, 2019, 09:21 AM
AndyKunz's Avatar
Thread OP
The unreliability of the engines gave them a different saying. Two turning, six burning, two silent. Or something like that. I guess that was still an improvement over the early B-29's self-detonating in flight due to a poor fuel line location.

Andy
Jan 28, 2019, 12:17 PM
Pro Hoarder
turbonut's Avatar
Cool Project.
I have an old TMHK kit. I think 88in WS..lots of hard wood in that kit..But nice plans to work from..Just have to update about 2/3rds of the wood parts..Watchin this one
Latest blog entry: In flight
Jan 28, 2019, 02:40 PM
Registered User
Subbed! That issue Flying Models was probably the first issue that I ever purchased; I HAD to build the B-36!!!! I haven't gotten to it yet
Jan 28, 2019, 02:42 PM
Gravity sucks.
mrittinger's Avatar
I think Don Belfort did one?
Jan 28, 2019, 02:54 PM
Wanted for breaking Ohm's Law
Dennis Sumner's Avatar
Looks cool Andy!

I always wanted to do a “36”. Looking forward to following along.....
Latest blog entry: RC Throw Gauge
Jan 28, 2019, 03:09 PM
An itch?. Scratch build.
eflightray's Avatar
If it helps at all, I found these --

B36 peacemaker "the big stick of the 50s" from zero to lift-off

The 12-foot foamie B-36 Peacemaker

I love the looks, but four motors is my limit.

Ray.
Jan 28, 2019, 04:26 PM
EB-66C Team Member
J Morgan's Avatar
Or you could do one as a pusher. The B-36 is a great planform and flies great.
Cool project Andy.

J
Latest blog entry: Ziroli A-1H at 100"ws
Jan 28, 2019, 04:38 PM
AndyKunz's Avatar
Thread OP
That's cheating!

I'm doing it as a 6X pusher! The custom electronics is part of the draw for me.

Andy
Jan 28, 2019, 04:43 PM
AndyKunz's Avatar
Thread OP
Where do you get Gus Morfis plans these days? I haven't seen him online for probably 4-5 years now.

Andy


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