I was aiming to build a small, light rocket, as thin as possible, to see just what performance I could get out of a minimum of propellant.
The case was 80 gsm photocopy paper, wound on a BBQ skewer, although much fatter than the ones I used for the stabilizer stick, about 4 mm in diameter. The overall length was 60 mm. The nozzle was compressed cat litter, and the bulkhead was paper wadding and hot melt glue.
The propellant was normal meal blackpowder. Loading such a narrow case with this propellant is a challenge, I had to make scoops and funnels out of card and foil. The fat skewers were used as drifts to consolidate the grain and nozzle.
The grain was packed from the bulkhead down towards the nozzle, and the nozzle formed with a recess of about 5 mm from the end of the tube.
The cavity was drilled out by hand using a 1.5 mm twist drill. The depth of the cavity was only about 20 mm. I don't normally use this procedure, prefering to construct the device on a mandrel, but as the entire design was brand new and so small as to be fairly harmless I thought I'd give it a try.
The cavity was primed with some loose meal powder and a meal-NC paper fuse was pressed into the recess and held in place with a small patch of tape.
Beautiful flight!
The performance wasn't all that great, but that wasn't the point of this rocket. The rocket appeared to thrust for only 350 ms or so, perhaps consuming all its core-burning zone in that time.
The tail from the remaining low-thrust end-burning phase was very attractive, like a comet, showing the path of the rocket as it flew several hundred metres down-range, landing in the ocean.
| title | type | size |
|---|---|---|
| Rocket Launch | video/x-msvideo | 2.569 Mbytes |
| Pre-Launch Photo | image/jpeg | 20.200 kbytes |