Beach Shoot #14 - Flying Hummer
Date: 2003-11-29
Description
A unique experimental device. Built from a normal 12.5 mm ID 25 mm long thick-walled hummer tube. End plugs of wax treated cat litter and propellant of straight meal.
Instead of the 1.8 mm vent hole being drilled tangental at the centre of the device length, it was drilled from the bottom edge, tangental and upwards towards the center. The result was a nozzle that pointed down about 45 degrees, but was still tangental and pierced the composition grain near the centre of its length.
It was fused with meal-NC paste priming and thin blackmatch as usual.
Comments
Suprising Performance!
I was half expecting 'ground bloom flowers' rather than any kind of flight. It took off like a 19 mm stinger, with a profoundly loud scream, even for a 12.5 mm hummer.
The spin frequency peaked at around 625 Hz or 37.5 kRPM.
The short burn put it about 50 metres up before two final puffs of sparks then blackness. It is unknown how much higher it went, the landing was not heard. It likely landed in the middle of the drainage cutting, about 100-150 metres down the beach towards the bridge.
I guess the good performance can be attributed to the large burning surface area, the relatively solid and low-ablation nozzle, its compact mass and the low air resistance profile.
Its squat flying hocky-puck like mass distribution probably gave it good stability at take-off, unlike a Z-bomb which it greatly resembled in construction.
Attachments
| title | type | size |
|---|---|---|
| Test Video | video/x-msvideo | 590.848 kbytes |
| Pre-Test Picture | image/jpeg | 25.064 kbytes |
| Spectrogram | image/gif | 134.192 kbytes |