Balcony Shoot #13 - Core-Burning Rocket

Date: 2003-10-14


Very similar to the previous device that worked so well. 5 mm ID pasted paper tube, 10 mm OD, 50 mm long. 2.5 mm core and nozzle (cat litter), 40 mm deep (not 50 mm like previous device). Bulkhead seal of paper wadding and hot-melt glue.

New batch of modified blackpowder meal propellant. Composition was very similar, but with added Aluminium:

18 Potassium Nitrate

6 Charcoal (-200 mesh)

3 Sulfur

2 Aluminium (-325 mesh, spherical)

The composition (sans the Aluminium) was ball milled for 1 hour, then the Aluminium was screened in using a few passes through a 60 mesh screen. This composition is much hotter than the mortar and pestle batch, so I shortened the core to compensate a bit. This also gives 10 mm of head-end composition to burn through for future delay and passfire to head effects.

A small amount of loose propellant meal was used to prime the core as a passfire from the fuse. I was running low on meal-NC fuses, and the remaining ones were a little fat to easily fit into the nozzle and core.

Standard stick for a stabiliser, although I used one of my red painted ones (which are about 30 mm shorter), just in case it landed somewhere recoverable. Again, the stick was glued on rather than taped, this is proving a very rapid and reliable technique.


Another great performer!

Video conditions on the balcony are pretty poor, so again the video doesn't show the true beauty of the effect or the height reached by this tiny rocket.

The altitude reached was about the same as the one launched at the beach, maybe a little higher, it was still going up well after burn out. The path wasn't as straight as the previous rocket, it pulled up into a more straight-up path near the end of its powered flight, this may have been weather-cocking, or perhaps some kind of instability from the shorter stick.

I think this design is ready for head effect experiments.


title type size
Launch Video video/x-msvideo 694.586 kbytes
Pre-Test Picture image/jpeg 24.486 kbytes