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Old Apr 01, 2015, 09:59 AM
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Build Log
B36 peacemaker "the big stick of the 50s" from zero to lift-off

Hello guys. This is actually not a build-log in real-time because the plane is already nearly finished yet but I thought it's still worth sharing some experience.

I went into a B36 peacemaker. yes! Why would somebody do such a build? My background is as follows: I built and flew several twin engine electrics then I finished my 4-engine C130 which flew superb right away. So I thought how could I repeat my experiences in a similar model? The B36 has a simple fuselage - let's do it.

The model bases on cores of white expanded styrofoam sheeted with 1mm-balsa.

I had a set of old plans from the 60s seemingly 100 times copied already but nevermind .
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Old Apr 01, 2015, 10:02 AM
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Nose and tail built up in oldshool style with planking balsa over formers. Sounds easy but just took time...
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Old Apr 01, 2015, 10:05 AM
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For transportation reasons I decided to go with a fixed ruder and removeable elevators. Each side received one servo. Connection with MPX connector and MPX snap-lock.

Pictures shows cutting rudder core and finished rudder.

-Jens
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Old Apr 01, 2015, 10:09 AM
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Cutting the wings brought a huge progress and some new motivation. As for the spar I was very limited with space. I decided to build an I-beam for maximum strength at low weight.
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Old Apr 01, 2015, 10:12 AM
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Nacelle time. These babies took siginifcant time to complete with planking over formers... Cooling air inlets were made from solid balsa.
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Old Apr 01, 2015, 10:14 AM
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And this is were I made my first huge mistake that drove me crazy nearly a year later....Oouch. Can anyone guess from the pics already? To be continued..
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Old Apr 01, 2015, 10:34 AM
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Slip the surly bonds...
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You didn't build in the wiring? I nearly said "you put the motors on back to front"
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Old Apr 01, 2015, 11:21 AM
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Oh no, not again!
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Quote:
Originally Posted by Sopwith Mike View Post
You didn't build in the wiring? I nearly said "you put the motors on back to front"
Nope, I can see the connectors in the wing end panel. Gear looks great too. In fact the whole model is very neatly done.

The mains are proud of the wing, but the real one had bulged doors for the same reason, so that can't be it. Hmmm.

Jeff
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Old Apr 01, 2015, 01:36 PM
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Haha, good guesses but more subtile. All wiring is included as well as 4x flap servo.

The plans I had didn't show CG (how mad is this...) and second I never built a plane with such a swept back wing. I was not aware of the fact the CG sits far rear on such wings. I installed my main gear with so much enthusiasm that the plane could not stand on gear after completion.

Much later I used two computer programs to calculate the CG. An american tool and a german tool. Both agreed on the same CG (awesome) but after balancing everything correctly the nose gear was in air .

This set me back for weeks...The whole maingear plywood frame had to be dremeled out. The wheel base had to be filled with foam partially, balsa and glass and everthing had to be installed back again as far back as ever possible.

Lesson learned for life.
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Old Apr 01, 2015, 01:43 PM
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The nose gear story. Well, this had to be thought over carefully as well. Space was limited as usual and it retracts forward.

How to set up a design of servo control if you don't have much room in your nose? I didn't like pull-pull-wires at all. These are not reliable and will get caught anywhere.

Ok - these were my ideas: The steering servo sits rearwards and is connected to 2x carbon tubes using ball links. The nose gear leg has a little alloy bracket where 2x carbon fiber wires connect. The length of the tubes is set up correctly when they hit the nose gear leg when gear is down. The wires slide within the tubes. Doing so I have a nice push-push connection. When leg is down the servo can turn free (carbon fiber tubes move free over carbon fiber wires).

Works flawless and reliable.
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Old Apr 01, 2015, 01:47 PM
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Slip the surly bonds...
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I like that - very neat.
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Old Apr 01, 2015, 01:47 PM
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The wing saddle needs not much explaination. Just stay smart and cut nicely. You don't need any heavy sanding steps here.
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Old Apr 01, 2015, 01:56 PM
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Sadly I was to lazy to take more pictures in those days. I am still a youngster and time matters. We make a huge step here and take it out for a close look and a full system test. Test of the pneumatic gears. Testing and adjusting all six flaps. I believe 2 years had passed by. Flying pictures and info on the power system to follow shortly.

Not to forget my second and third big mistake I made.

-Jens
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Old Apr 02, 2015, 10:30 AM
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Gravity sucks.
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No wonder there's a balsa shortage!
Nice work.
Re cg/ gear placement....Generally, on a trike gear, draw a line 15-20 rearward from cg at wing, and where it contacts the ground is where you place your rear gear.
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Old Apr 02, 2015, 12:08 PM
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Looks super!!

--Stacker
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