whoof

Saw this today may be of interest to collectors, http://www.ebay.co.u...=item4d0d089c5c

Aww nuts, saw it too late,auction closed.
I've been looking for bits/ fuel for years.

http://www.ebay.co.u...r-/321107196095

If you did not see the advert, this may be of interest.

 

http://www.star-prot...nomy-fix-to-pm/

this is whart i used when i used to test my bp for the first time. about
 
"If you drop an object and time its descent to the ground, the distance the object has fallen, in feet, is given by the equation, Distance = 16 x time x time (16 x time squared), when the time is measured in seconds.
For example, if I fire my baseball, and start a stopwatch when its flight peaks out at apogee, and then stop the stopwatch when the ball hits the ground, I'll be able to read the time it took the ball to fall to the ground from that peak. Let's say that my stopwatch indicates a time-of-fall of 4.18 seconds.
 
Timing the Fall of a Dummy Shell

To see how high the baseball was when it started to fall (at apogee), all I have to do is multiply 16 x 4.18 x 4.18 and I get a height of 279.55 feet. That's pretty close to my desired 300 feet. So I know that using the amount of lift powder that I used, or maybe just a tad more, would be a good quantity of that BP to use in the future for this size and weight shell."

It's a good approximation up to about 200 feet I think.
After about 2.secs it reaches 20 m/sec and after 3 ' 30 m/s.
However the terminal velocity of a baseball sized object is about 36 to 40 m/s so after approx 3.5 secs it will fall at a constant speed.

 

edited figures due to brain fade

 

Iv done somemore sums and the error becomes 15 % at around 450 feet so its not a bad approximation  after all unless you are firing monsters. 

Exscuse my ignorance, what proportion of a 1 lb rocket would be propellant in a bp motor?

Exat's store

Not much point.
You would probably have to wear a blindfold anyway.