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Showing posts from June, 2022

Wheels and landing gear

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I used 3" Dubro spoke wheels. Although not exactly scale size I chose them because I typically fly off of a grass field. These wheels are thin and light, and may later be useful if I want to convert them to wired spokes. I decided to cover them with orange tissue so I first removed the foam and glued balsa to form a surface. I then covered the balsa with orange tissue and reassembled the foam rim: The landing gear is a simple wire frame with the wheel axis held in place by silicone rubber bands that I sliced off of a rubber tube:

Covering

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I selected Esaki tissue from Peck Polymers; picked blue and orange that best fit the end result I wanted to achieve: colors that are close to the actual plane and a covering material that will highlight the model's structure. These are the horizontal stabilizer and elevator fins covered in orange tissue with two coats of sealer: After practicing on the stabilizers, elevator, and rudder I turned my attention to the fuselage. The complex contours posed a challenge that I wanted to tackle first and here are some results. The windows are covered and cut away after applying a coat of sealer to the covering, leaving the cross members covered: A view of the internal setup and a top view of the battery hatch: The battery hatch is located at the bottom of the fuselage behind F3. The hatch is secured with a simple swiveling latch and a silk strap:  

Wing struts

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 Struts are made according to the plans with bamboo skewers and 1/8"x1/2" trailing edge: With the wing braced to the fuselage and verified to be square and level I glued the struts together per plans. The front and back struts are glued with epoxy: The connectors as the strut tips are small automotive cable connectors. The blue will match the covering color of the fuselage, one end matched the skewer diameter, and the other end has a metal loop that exactly matched the #4-40 screws I used to secure the struts: A view of the finished and sanded struts connecting wing and fuselage. The #4-40 nylon screws fit into blind nuts embedded into the side of the fuselage and into gussets under the wing:

Completing the wing

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The wing has no dihedral so attaching the two panels was relatively straight forward. I cut a dihedral brace from 1/16" light plywood and fit it into a slot cut into the main spars. The slot runs through the first bay and the brace then fits between the spars in the second bay: The completed wing with both panels glued into one: Wing attachment to the fuselage uses a setup that has a "hook" in the front and two nylon screws in the back. The hook is make of 1/16" light ply with 1/8" balsa filler in between, and is glued to the dihedral brace. I also added a thin ply strip to the top of F2 that centers the hook and prevents it from sliding sideways: The wing is braced to the top of F3 by two #6-32 nylon screws. The crews go directly into the 1/8" triangle gussets without any blind nuts. There was no space for the blind nuts and the hole in the gusset is threaded and reinforced with CA to preserve the threads:

Aileron servo

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Aileron servos are Hitec HS-40. They will be permanently glued to a tray on the wing and linked to the ailerons: The servo will be glued to the tray after the bottom covering is in place and before the top wing covering is attached.