I built the whole thing pretty sturdy, with the tweaks below. The following have all been done on the forum or are in one of the rocketry books, or on video, I don't think anything is original but thought it would be convenient to put it all together on a single low power rocket. I did come up with an easy way to make 3/8" hinges that may be useful in LP. I normally do this only on kits and small paper min dia models. If it's a home design it gets through the wall mounts! Bigger hinges are stronger but covering the lines becomes more difficult.
Glued the screw eye in with 5 minute epoxy, and applied water thin super glue to all of the body tube and motor mount tube edges. Additionally, on the upper stage "green" tube motor mount, I applied Tite-Bond II to the exterior of the tube. This motor is tape secured so this is to prevent tape removal from peeling paper (Apogee Aspire kit 24 mm adapter instructions). Good idea. I also coated the stage coupler interiors with Tite-Bond II for a little increased burn resistance at separation.
Since all of the fin material is 1/16" all fins were papered, and all fin joints and root edges were pre-sanded to break glassine and primed with Tite-Bond II. Additionally made glue rivets (pinholes in body tube under the fin) for some additional strength. Apogee BT50 x 3 fin jig was used to position fins. This required tape shims, 3 or 4 layers thick on each side of the jig slot for alignment. Fin edges will get thi super glue treatment shortly.
After fin joints were completely dry, applied fillets. Upper stage simply got fillets, boosters with their giant fins got some special treatment. See pics. I added paper hinges over the single fillet on the booster fins and allowed to dry. Applied 3 thin layers of glue with a brush and dry times between, then a fillet over the joint.
It's easiest to make the hinges in strips from a sheet of paper, using a straight edge to mark and make the fold. Then cut the hinges off of the strip, I made the upper edges parallel to the leading edge for looks and neatness. The glue layers over the hinges are important and help reduce the inevitable filler putty at the end.
Cheers / Robert
Glued the screw eye in with 5 minute epoxy, and applied water thin super glue to all of the body tube and motor mount tube edges. Additionally, on the upper stage "green" tube motor mount, I applied Tite-Bond II to the exterior of the tube. This motor is tape secured so this is to prevent tape removal from peeling paper (Apogee Aspire kit 24 mm adapter instructions). Good idea. I also coated the stage coupler interiors with Tite-Bond II for a little increased burn resistance at separation.
Since all of the fin material is 1/16" all fins were papered, and all fin joints and root edges were pre-sanded to break glassine and primed with Tite-Bond II. Additionally made glue rivets (pinholes in body tube under the fin) for some additional strength. Apogee BT50 x 3 fin jig was used to position fins. This required tape shims, 3 or 4 layers thick on each side of the jig slot for alignment. Fin edges will get thi super glue treatment shortly.
After fin joints were completely dry, applied fillets. Upper stage simply got fillets, boosters with their giant fins got some special treatment. See pics. I added paper hinges over the single fillet on the booster fins and allowed to dry. Applied 3 thin layers of glue with a brush and dry times between, then a fillet over the joint.
It's easiest to make the hinges in strips from a sheet of paper, using a straight edge to mark and make the fold. Then cut the hinges off of the strip, I made the upper edges parallel to the leading edge for looks and neatness. The glue layers over the hinges are important and help reduce the inevitable filler putty at the end.
Cheers / Robert
