Mach 1 Dart with RX-1 Thruster System
I flew my first Mach 1 Dart with RX-1 Thruster System when I was a teenager .....
After several flights purchasing the motors (RX-1 Thruster System) I looked for a less expensive alternative and something for small field flights. The Dart model and booster that I built in the images below have the 21mm mounts in both stages, meaning Semroc ST-8F tubing less the motor mount in the Dart. When FSI 21mm motors were available I used D20 or D18's in the booster and usually D18's in the Dart. Always turned in perfect flights.
This design is based on 18mm motors and uses all Semroc parts. The chamfer on the top of the booster on the original was actually the top of the F100-0 that had been rounded for a smoother transition between the Dart and the booster. This is the perfect place to use Apogee Fix-It Epoxy clay. The inside tube should be just a little longer so you can run a little snake of clay around the tube and smooth a really nice transition. If you look closely you can see this on the images with the booster separated from the Dart.
Use 1.00" motor overhang to give the Dart motor enough length to slide into the booster ST-30 mount.
Diameter: 0.921" Dart (ST-8F) / 1.170" Booster (ST-11)
Span Dia: 4.920"
Weight: 1.551 oz
C6-0 / C6-7.......2,181'.........DV 3 FPS.........36" x 1/8" rod
For kicks I left the data in the flight simulations from a Mach-1 Dart two stage model, since I revised my FSI file that used parts data that I had recorded from an original kit.
F100-0 / D20-10.......3,249'.......DV 26 FPS.......36" x 1/4" rod
Max Velocity: 1,070 Feet / Sec.
Max Acceleration: 1,778 Feet / Sec / Sec