Determined not to make the entire shoot a bust I went back into the lab and pieced together a quick half-saxon.
Fairly small device, 5 mm ID, 9 mm OD, 50 mm long, end seals of paper wadding and hot-melt glue. Probably 35-40 mm of actual composition space inside.
Same composition as the wheel, 90% BP meal, 10% spherical Aluminium dust. Pressed hard by hand, not rammed with a mallet.
2.5 mm nozzle hole, punched into the side using a metal BBQ skewer. Fused with thin blackmatch held in place with a gob of meal-NC paste (I just dipped the end in the paste then shoved it in the hole).
Hot-melt glued to the pivot cardboard strip of the first wheel driver test. Took all of about 5 minutes to make, including screening the metal into another batch of propellant.
Worked great!
Interesting that the effect changed throughout the burn, perhaps because I didn't screen the propellant batch enough, but it worked out OK.
Fairly short burn, but the device was quite small and the meal is pretty hot. The hole didn't widen very much which was lucky. The case chared a lot post-burn as the heat soaked through, it wasn't all that thick.
| title | type | size |
|---|---|---|
| Burn Video | video/x-msvideo | 1.617 Mbytes |
| Pre-Burn Picture | image/jpeg | 24.170 kbytes |
| Post-Mortem Picture | image/jpeg | 55.821 kbytes |