I posted a little while ago about scratch building a Boeing Bomarc from 3D printed parts I designed / printed and BT60 + BT55 ramjet tubes + BT20 top pod. Model comes in at around 25" tall and 215 grams. I wound up putting a 1oz weight in nose to make sure this would be stable.
Finally had a chance to test launch this guy today and it flew great. Designed this for D engines and flew it on a D12-3 today. It arched a tiny bit over the top of the model but that could have been a bit of wind cocking based on the direction of the wind. Very little twisting or spinning which people had mentioned was a problem with these models (and honestly my ramjets are not even perfectly centered / distributed). I had a failed chute deployment but that is likely because I did not put enough wadding in and/or had parachute too close to engine. Anyway, model more or less "glided" to a landing due to large wings and nose-cone being off so no damage (nice damp to muddy field).
The BT55 tubes are a bit larger than scale but closer than a BT50 tube would be (too small) so I went with it. Happy with the model although my wife says it looks like a plane and not a rocket or missile. One delay was cleaning up what wound up being a very bumpy top pod. I tried to reshape a BT20 tube half so it would be a bit taller and thinner than stock (I used some 3D printed half loops in middle and two ends have tapered 3D printed parts). Anyway, part wound up twisting and was really bumpy when it set up. I finally found my wood filler and was able to straighten things out with wood filler (actually amazed it looks as straight as it does)
Finally had a chance to test launch this guy today and it flew great. Designed this for D engines and flew it on a D12-3 today. It arched a tiny bit over the top of the model but that could have been a bit of wind cocking based on the direction of the wind. Very little twisting or spinning which people had mentioned was a problem with these models (and honestly my ramjets are not even perfectly centered / distributed). I had a failed chute deployment but that is likely because I did not put enough wadding in and/or had parachute too close to engine. Anyway, model more or less "glided" to a landing due to large wings and nose-cone being off so no damage (nice damp to muddy field).
The BT55 tubes are a bit larger than scale but closer than a BT50 tube would be (too small) so I went with it. Happy with the model although my wife says it looks like a plane and not a rocket or missile. One delay was cleaning up what wound up being a very bumpy top pod. I tried to reshape a BT20 tube half so it would be a bit taller and thinner than stock (I used some 3D printed half loops in middle and two ends have tapered 3D printed parts). Anyway, part wound up twisting and was really bumpy when it set up. I finally found my wood filler and was able to straighten things out with wood filler (actually amazed it looks as straight as it does)