B-17 Build Log

Now that the design part of this is done I figured its time to start fresh with a build thread in case anyone wants to follow along.

The concept here was to make something a little different yet still be fairly easy to build. I also wanted to teach myself how to use CAD. In order to simplify things, the plane is based around the power pod concept and has a mostly square fuselage. Definitely not going to be the prettiest B-17, but if this works I will redesign her to have more of a B-17 look. I am using just a small amount of 1/8" plywood in order to give my Landing gear something solid to mount to, but other than that, it is all DTFB.

For motors I will be using the power pack B setup from the Flite Test store (plus two additional motors and ESC's.) There will be two servos for each elevator using a radio mix to control. I was debating on doing differential thrust and no rudder, but with FOUR motors, Im afraid I'd rip the wing off. Although I designed it to have a removable wing, I also incorporated a removable nose fro quick access to the battery. (assuming my CG allows me to put the battery up front... fingers crossed.)

I designed the plane in Sketchup using this 3 view drawing:

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After many many changes, I decided this would be how the prototype will look:

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Next up was laying everything out in groups of 20x30 so all the parts could be cut. I made a set of plans but Im making small corrections as I go so they aren't what I would call a final product yet.

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Here are the plans: View attachment 104847

After cutting all the parts I started to build the wing. First up are the nacelles and power pods. pretty straight forward, just have to realize that each one is slightly different so labeling is a must to keep them organized and together as groups.
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(That big piece is the Lower nose... I was curious to see how it would look size wise)

To build the wing panels, first step is to join the lower inner and outer panels. (I decided not to glue the upper pieces together and fold them over individually. That worked for me..)
The main spar is in four pieces- the joint for the fwd spar is offset by about 5 inches from the joint of the rear spar. So that way when they are glued together it makes a very strong piece. I glued all four pieces together with white gorilla glue and on the panel at the same time so I could make sure everything was straight. Same with the center spar. The short center spar is perpendicular to the centerline so I can use a joiner when both wing halves are assembled together.

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Before folding the upper wing over the landing gear mounts inside the wing need to be glued in. No, my ply isn't pretty, but nobody will ever see it again. Its also very important
at this point to use a pin and poke a few holes through the nacelle cut out reference marks so that once the wing is folded over you will know where to cut the openings. I also marked the top of the spar where the nacelles go so I wouldn't put glue in that area.

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I folded the inner wing top over first using a piece of aluminum bracket clamped to the table to help me allign the top and bottom. also note that the trailing edge has to hang off the table since it sits lower than the bottom of the wing. Once that was glued down I folded over the outer panel. I was happy to find that everything lined up perfect.

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Next step is to carefully cut out the openings for the nacelles to slide into. Since its always better cut a little small and make it bigger if you have to, I made the opening slightly smaller than my reference pin holes. Then using a sanding block I cleaned the openings up a little at a time until they are just right. Here you can see the hole I made in the spar to pass the wires through.

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And I finally get to see the work pay off. The nacelles slide right in and lock into the spar as I designed them to. I won't glue them in until after the wing halves are joined and the wiring is done. Im pretty happy with how it looks. Im thinking I might go back to the design and add flaps, although it should be pretty easy to cut them in to the finished wing. Im still working on getting the cowl design just right. I think the slight bit of roundness helps the look.

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So far so good. Im really happy with how its coming out so far.
Before I build the other wing half I am going to build the fuse to see if the wing will fit.