MarkII
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Well, someone had to get this gallery established. Here are pics of my Birdie clones. As you can see, the shuttlecock doesn't exactly match the one that Estes used. Despite much searching, I simply couldn't find any with plastic shirts that matched that particular design, and I'm not so sure that they are even being made anymore. So I did the best I could.
The red one is a clone of the original K-44 Astron Birdie, which was designed to be flown on 18mm x 45mm Series III motors. For its maiden flight, I thought that I could get away with using an unmodified A8-3 in it. I reasoned that the extra length was mostly just empty casing, with negligible weight, so I was pretty sure that it would work. A quite fierce loop off the launch rod, followed by a power prang demonstrated otherwise. Since then it has had successful flights on A10-3Ts placed in cut-down spent 18mm motors.
The green one is based on plans for the TK-44 Birdie Mini Brute. This variation was introduced shortly after Estes Industries phased out the Series III motors and replaced them with the 13mm x 45mm Series IV "T" motors (aka Mini Brute motors) that continue to be produced to this day. In Bill Simon's designs for the Astron and Mini-Brute Birdies, the RA-2060 and RA-560 centering rings fit into the plastic skirt just aft of the large vent openings, which blocked the airflow at that point. I decided that for my build, I would insert a cardstock shroud inside the skirt ahead of the centering ring, in order to fill in the vents and streamline the air flow somewhat. I still had to cut an opening in it for the launch lug, though. My closed-skirt TK-44 clone does fly appreciably higher than my vented-skirt K-44 clone, but other factors may contribute to that. I suppose that I'll have to construct another TK-44 that does not deviate from the original design, and then fly them together to make a more reliable comparison. The streamline Birdie also comes back in at a somewhat higher speed too, though. But even then, it's velocity seems to be far slower than that of a batted (racquet-impelled) shuttlecock.
Both Birdies are incredibly stable, even in a breeze. They boost straight up, and at apogee, they eject their motors. (A3-2Ts are just about perfect. A10-3Ts eject a little late, but still fire while the Birdie is way, way up there.) Then they fly straight back down, with little to no drift. I have become accustomed to seeing mine strike the blast deflector on the pad after coming back home from 300+ feet. They don't do that every time, but they do it often enough. The Birdies and their ejected motors hit the ground nearly simultaneously.
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The red one is a clone of the original K-44 Astron Birdie, which was designed to be flown on 18mm x 45mm Series III motors. For its maiden flight, I thought that I could get away with using an unmodified A8-3 in it. I reasoned that the extra length was mostly just empty casing, with negligible weight, so I was pretty sure that it would work. A quite fierce loop off the launch rod, followed by a power prang demonstrated otherwise. Since then it has had successful flights on A10-3Ts placed in cut-down spent 18mm motors.
The green one is based on plans for the TK-44 Birdie Mini Brute. This variation was introduced shortly after Estes Industries phased out the Series III motors and replaced them with the 13mm x 45mm Series IV "T" motors (aka Mini Brute motors) that continue to be produced to this day. In Bill Simon's designs for the Astron and Mini-Brute Birdies, the RA-2060 and RA-560 centering rings fit into the plastic skirt just aft of the large vent openings, which blocked the airflow at that point. I decided that for my build, I would insert a cardstock shroud inside the skirt ahead of the centering ring, in order to fill in the vents and streamline the air flow somewhat. I still had to cut an opening in it for the launch lug, though. My closed-skirt TK-44 clone does fly appreciably higher than my vented-skirt K-44 clone, but other factors may contribute to that. I suppose that I'll have to construct another TK-44 that does not deviate from the original design, and then fly them together to make a more reliable comparison. The streamline Birdie also comes back in at a somewhat higher speed too, though. But even then, it's velocity seems to be far slower than that of a batted (racquet-impelled) shuttlecock.
Both Birdies are incredibly stable, even in a breeze. They boost straight up, and at apogee, they eject their motors. (A3-2Ts are just about perfect. A10-3Ts eject a little late, but still fire while the Birdie is way, way up there.) Then they fly straight back down, with little to no drift. I have become accustomed to seeing mine strike the blast deflector on the pad after coming back home from 300+ feet. They don't do that every time, but they do it often enough. The Birdies and their ejected motors hit the ground nearly simultaneously.
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