Sooner Boomer
Well-Known Member
- Joined
- Mar 21, 2011
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The Scissortail Flycatcher is the State bird of Oklahoma. It seemed like a fitting name for this rocket.
I was thinking about a method of recovery that was more-or-less passive. One that didn't require any preparation, and would be fairly fool-proof and easy to use. What came to mind was some way of changing the configuration from one of low drag (flight) to one of high drag (recovery). Several gliders do this, as do helicopter-recovery rockets. I was looking for something a bit more novel. This is what I came up with.
It's a six inch BT20 with a stock Estes plastic nosecone glued on. I made two spars from basswood that carry the fins. The fins are from a Baby Bertha kit I bought and turned into a Baby Fat Boy before Estes came out with one. The spars pivot on a wood dowel just under the nosecone (I think I probably used a bamboo skewer). There are arms on each spar below the pivot point, that attach to elastic thread. The tension provided by the thread swing the spars out into the recovery position. The other end of the elastic is retained by a ring (made from a scrap piece of body tube) glued on the aft end of the rocket. A conventional style engine block ring (with cardboard disk plug) holds the engine in place during flight. Prior to flight, the spars are swung into flight position and an engine is inserted. Short arms at the aft end of the spars are held against the engine by the tension of the elastic threads, and the engine prevents their movement. At ejection, the engine is kicked out of the body tube, allowing the spars to swing up into recovery position. The rocket uses tumble recovery.
I was thinking about a method of recovery that was more-or-less passive. One that didn't require any preparation, and would be fairly fool-proof and easy to use. What came to mind was some way of changing the configuration from one of low drag (flight) to one of high drag (recovery). Several gliders do this, as do helicopter-recovery rockets. I was looking for something a bit more novel. This is what I came up with.
It's a six inch BT20 with a stock Estes plastic nosecone glued on. I made two spars from basswood that carry the fins. The fins are from a Baby Bertha kit I bought and turned into a Baby Fat Boy before Estes came out with one. The spars pivot on a wood dowel just under the nosecone (I think I probably used a bamboo skewer). There are arms on each spar below the pivot point, that attach to elastic thread. The tension provided by the thread swing the spars out into the recovery position. The other end of the elastic is retained by a ring (made from a scrap piece of body tube) glued on the aft end of the rocket. A conventional style engine block ring (with cardboard disk plug) holds the engine in place during flight. Prior to flight, the spars are swung into flight position and an engine is inserted. Short arms at the aft end of the spars are held against the engine by the tension of the elastic threads, and the engine prevents their movement. At ejection, the engine is kicked out of the body tube, allowing the spars to swing up into recovery position. The rocket uses tumble recovery.