Contributed by Bob Harrington
Components used were:
The instructions followed a logical sequence, however, it did not mention sanding the root edge of the wings at an angle to fit tight against the body tube. I also sanded the root edge of the rudders into a 'V' shape to fit tight between the main body and scramjets. I used a 24mm motor mount with a 3.75" engine hook to allow for Estes 'E' motors. The main body tube was 2 pieces joined with a coupler that was made into an ejection baffle. I used the standard tri-fold shock cord mount and an 22" parachute made from a plastic tablecloth. No nose weight was required.
The BT-70 tube and motor mount was from FlisKits. The BT-60 tube was from Balsa Machining Service and the Custom nose cone from Roachwerks Custom Turnings.
I chose a D12-3 for the first flight. The motor mount has an engine hook and I put a spacer to take up the extra room. I used an ejection baffle so no wadding was required.
My worries were well founded because the rocket attained about 100 ft of altitude before it turned horizontal into the wind. It was traveling really fast when the ejection charge went off. The chute was ripped off immediately and the rocket hit the grass hard.
When I went to survey the damage, I was surprised to find only a small dent in the body between the scramjet tubes, the forward edge of the tube was dented, and there was a small crease in the first 1 1/2" along the spiral. All the fins were intact and nothing was broken. The dents were pushed out and the nose cone has a 2" shoulder on it and will support the small crease. As it turned out, I was fortunate that its flyable again without having to make repairs.
It was going way too fast at ejection and the parachute distruction was to be expected. I will upgrade the chute to a ripstop nylon one before any further flight attempts just for my own piece of mind.
What You Can Do