Pasted paper tube, 5 mm ID, 10 mm OD, 50 mm long. Cat litter nozzle, wadding and hot-melt glue bulk head. 2.5 mm nozzle and core, full length of grain.
Propellant of modified blackpowder meal, prepared as a small quantity in a mortar and pestle, ground until it burnt "well" (ie no slag) on the testing can. Composition:
18 Potassium Nitrate
6 Charcoal (airfloat)
3 Sulfur
1 Aluminium (-325 mesh, spherical)
Metal was screened in last using several passes through a 40 mesh screen. The result was not much better than greenmix blackpowder, but it burnt clean with pretty Al sparks.
Standard stick stabilizer, although it was split in half to reduce the mass and tacked on with hot-melt glue instead of tape. Fuse was my standard twisted paper meal-NC fuse.
Completed device weighed less than 3 g, unfortunately the pictures I took were lost when my camera batteries died mid-compressing, I didn't realise this until after I had already fired it.
Absolute Screamer!
The video does not do it justice, I didn't tell my ever suffering camera girl that it was actually a rocket, she thought it was the next item up (a candle). So there isn't much of its flight in frame.
It went high, very high, at least 100 metres. The Al sparks in the tail made a nice effect. I have absoutely no idea where it landed, maybe in the surf, maybe further down the beach. Its a shame, I would have liked to recover this one.
It left a nice, straight as an arrow smoke trail, that gently drifted out to sea in the very light breeze.
A few more successful tests of this motor and propellant configuration and I'll feel confident enough to add head effects.
title | type | size |
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Launch Video | video/x-msvideo | 973.570 kbytes |