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Aug 08, 2019, 06:57 PM
Jer. 29:11
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Other Parts


The horizontal stabilizer and elevator are each made of two layers of 1/4 in. foam. After laminating the parts, sand the outlines square. Then bevel both top and bottom of the stabilizer and the elevator, and round the leading edge of the stabilizer and trailing edge of the elevator. I used 3D printed tools [1 and attached] for these tasks but a sanding block works too.

[1] Foam Airplane Bevel Cutting Tool on Thingiverse

The optional wing-tip tanks are each made from four layers of 1/4 in. foam. The inner two laminations have cutouts for the wing tips. Make one left and one right tank. After gluing, sand the tanks to shape. I rounded the edges with a 3D printed sanding tool.

Note: Don't glue the tanks to the wing tips until after the wing is glued to the fuselage. Later when the ailerons are added, they'll need to be shortened so they don't interfere with the tanks.
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Aug 13, 2019, 05:50 PM
Jer. 29:11
jeffsch's Avatar
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Fuselage and Wing


The next step is to glue the wing to the fuselage. Here's where attention paid to lining up the fuselage laminations pays off. Trial fit the wing into the fuselage. It should be a snug fit. With the fuselage sides vertical, each wing tip should be the same distance from the table. On the second prototype, I needed to open up the wing slot in the fuselage, so I used the nacelles to hold the wing level while the glue set up.

You can hinge the ailerons before gluing the wing to the fuselage. Or after. Either way works.

The ESCs likely need extensions to reach from the battery bay in the fuselage to the motors in the nacelles. I chose to extend the ESC to motor wires -- they needed to be 12 in. Fish a lead through the channel in the wing for these wires; I used a small washer tied to a piece of dental floss. While you're at it, fish a second lead through the same channel. Use one lead to pull the ESC wires from the fuselage, into the channel, and out at the opening for the nacelle.

Before gluing the nacelles to the fuselage, use the other lead to pull the aileron servo extension from the nacelle through the channel in the wing and into the fuselage. And then route the ESC wires through the nacelle to the opening in the motor mount, and connect the motor. If you're comfortable running the motors up on the bench before the nacelles are glued, this is a good time to connect your receiver and a battery, power up the motors and aileron servos, and verify the connections.

When you're happy with everything, tuck the wires into place, and glue the nacelles to the wing.
Aug 17, 2019, 06:40 PM
Jer. 29:11
jeffsch's Avatar
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Final Assembly


The optional wing-tip tanks are easy to add at this point -- you just need to shorten the aileron to clear the tanks.

I recommend hinging the elevator to the horizontal stabilizer before gluing the assembly to the fuselage. You may wish to add the control horn for the elevator at this point -- on the prototypes, the control horn goes on the bottom, right side of the elevator. Dry fit the horizontal stabilizer to the fuselage with the regular care to align it properly, and then glue it into place. (I used a few small washers to hold the stabilizer level while the glue cured.)

If you want a rudder, cut out and hinge the rudder to the vertical stabilizer. And add the control horn to the rudder -- goes on the left side. Attaching the vertical stabilizer to the fuselage is a weak point in this design. For both prototypes, I added short lengths of round toothpicks -- half into the vertical stabilizer and half into the top of the fuselage -- and this strengthened the attachment nicely.

All of the pushrods are 0.039 in (1 mm) wire. To reduce flex for the elevator and (optional) rudder pushrods, there are two standoffs that glue into the fuselage sides as marked on the plans. There are some commercially-available pushrod supports that would work well; I chose to 3D print some supports (files attached).
Aug 17, 2019, 06:49 PM
Jer. 29:11
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Kits


Kits include four cut sheets of Model Plane Foam, three hotwire sheets of 1 in foam, and some small 3D printed parts. Kits are for $35. Send me a PM to order.

Kits are shipped in a box 36 in x 12 in x 3 in that weights 1lb 6 oz. USPS Priority Mail 2 Day should be $14.10.

3D printed tools are $2 each: corner sanding tool, KF airfoil tool, round edge sanding tool, and/or bevel cutting tool.
Aug 17, 2019, 06:51 PM
Jer. 29:11
jeffsch's Avatar
Thread OP
After reviewing similar models, I upgraded the spar to a 5 mm carbon fiber tube. The CAD file and PDF plans in the first post have not been updated yet. I'll update this post when they are.


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