Scale Aviator International Magazine Issue 3 - Page 12

cockpit with pilot and anything else I could think of along the way. After much scrutinizing of the wings it was apparent that the gun and ammo bay doors were not possible due to the construction of the wing. So I got the brainy idea to make the canopy open and close remotely. I’m sure I could have purchased something but I’m not coded that way and tend to construct everything I possibly can as reasonable in function, appearance and cost as possible. While I was working on the cowl flaps and sanding the fuselage I began working out the details on this little sliding canopy project. Examining the cowl and factory mounting earlier I discovered the factory mounting was simple and 6 solid but it also happened to be glued to the cowl flaps which meant new mounting was required. Attaching the cowl with the factory mounting to hold it in position I built new mounting by adding stations on either side of the firewall box and fabricated plywood mounts for the cowl. Removing the cowl I secured the new cowl mounts to the stations with four 6-32 bolts, once secured I installed 3/8” dowel alignment pins in each side. With this all in place I reattached the cowl still using the factory mounting. I mixed up some 30 minute epoxy and added carbon fibre tow cut in ½” lengths. This adds incredible strength to the bond. Using heavy paper formed into a funnel, filled with the epoxy-carbon fibre mix I piped it in to glue the new cowl mounts 7 to the cowl, like decorating a cake. Once cured, I carefully removed the cowl and re-enforced the mounting with epoxy and layers of 2 oz. glass cloth ing two small nylon hinges per flap I attached them to the cowl and then carefully glued the cable with for a permanent bond. See Photo #6 supports in place. I used 3/32 brass rod silver solRemoving the factory mounts from the cowl I reat- dered to the drive points on the cable to actuate tached it using the new mounting and proceeded each flap. For the attachment point on the flap I to cut the cowl flaps from the cowl using a razor once again silver soldered the appropriate sized saw. After separating the individual flaps I taped tubing to a length of flat stock and cut 3/8” pieces, them back into position and discovered that they one per flap. I dressed the tubing on each piece were wrong compared to the three view drawings so it would easily slide on the brass operating rod and made a couple new flaps to make it right. I and epoxied them on to the flaps. When the cable had mentally worked out a mechanism to operate rotates, each rod will drive the attached flap, while them using a portion of a speedometer cable as it’s moving the flap the rod glides in the attachment the back bone. I made supports for the cable by piece providing smooth operation without binding. silver soldering the appropriate sized brass tub- The entire mechanism is driven with an Airtronics ing to a length of brass flat stock and then cut 1/8” 94851 servo connected to a nose wheel tiller arm pieces to make the individual supports. One of on the cable. It has nearly 200 in o z. of torque easthese will go on either side of each flap with an- ily providing solid operation. See Photo #7 other piece of tubing in-between silver soldered to the cable to provide a drive point for the flap. Us- All this time I was still filling and sanding on the f g k 12