"James Waldby" wrote in message ...
On Tue, 26 Feb 2013 21:06:33 -0800, PrecisionmachinisT wrote:
"jon_banquer" wrote ...
Never made my own. I used the Estes solid rockets. Half the time when the
parachute opened the rocket was carried so far I could never find it

The estes still make for a fine bottle-rocket, scrape the clay
parachute-launch barrier loose to expose some actual fire to your
burst-charge, which can be contained in an end mill tube that's been
duct-taped to the top of the rocket tube.

A word of warning, you need a LONG stick and /or you need to attach weughts
to the bottom of the stick...the nozzle is the pivot point; if it is not
also the balance point ( a top-heavy rocket will overturn if you attempt to
balance the nozzle on your finger...if it does, then the trajectory is
basically random...the nozzle must ALWAYS stay pointed downwards if you want
to shoot for the moon instead of your neighbor's Cadillac.

Adding weights at the bottom is wrong way round -- the condition for
aerodynamically stable flight is center of gravity *above* the center
of pressure. Eg see following and some links from it.
http://exploration.grc.nasa.gov/education/rocket/rktstab.html


The goal here was to maintain a self-correcting, straight-up trajectory, not to hit a target located some distance away...

--with the proper amount of weight attached to the end of the stick, they would quickly arc in an upwards direction and assume a purely vertical climb even if launched horizontally.