My search for a reliable strap-on booster dropper lead me to this little device.
It had to be easy to make with only a lathe and a drill press.
It had to drop the boosters without getting stuck at an odd angle.
A 1/4"-20 nylon screw with a groove of 0.135" machined into the middle is broken when
a 0.1g charge of Pyrodex P is ignited by an e-match.
These are pictures of a test rocket (boosters I161W-S, main J135W )
which is scheduled to fly at ROC's September launch, it will have two boosters.
If all tests are successful then a 1/12 scale Delta III is next.
The tube on the left (strap-on booster) is 3.0" Quantum Tube from PML.
The main airframe on the right is 6" phenolic of unknown origin.
They are now available for $70/pr.
This is the CAD drawing: boosterdropper.pdf
Here is an alternative use for my Booster Dropper. BDexample.pdf
The pdf show how three or four Booster Droppers could be used to couple the stages
of a big two stage rocket.
Here is a movie of the first test it's 11MB.
Or six frames in jpg format of only the drop 1 2 3 4 5 6 about 140KB each.
If you have a slow connection download 3 it shows after firing with the booster mid air.
At the September ROC launch (9/8/01) a test vehicle was launched. Doubed the "Booster Pooper" by Doug Gerrard http://www.rocketryphotography.com/, weighing in at 27.5 pounds with an 8mm movie camera as payload. The motors in the boosters are I284W-S's and the center motor is a J135W-P.
On the pad bp1.jpg(20k)
Leaving the pad. Note the J135 is not up to pressure yet.bp2.jpg(24k)
In flight the J at full power and the I's fading. bp3.jpg(12k)
The boosters are clear. bp4.jpg(12k)
And that J135 just keeps on going. bp5.jpg(28k)
Max Accel 6.9g. Max Alt 2842ft 15.5 seconds to apogee.
Doug Gerrard's text of his booster dropping rocket. (avi 3.3MB)