* Posts by Cagey

6 publicly visible posts • joined 15 Apr 2011

LOHAN breathes fire in REHAB


APCP Burning Characteristics in REHAB


I watched your REHAB test today with extreme interest. As per some of the other comments regarding the pressure inside the REHAB chamber I question the ability to maintain a high vacuum after the igniter fired. Both the Aerotech and Cessaroni motors use Ammonium Perchlorate Composite Propellant (APCP) which has a positive coefficient of burning with respect to pressure. In other words the higher the pressure inside the motor the faster the propellant burns.

This would explain both the failure of the Aerotech motor to remain lit and the long delay between igniter activation and the full power burn of the Cessaroni reload. The Aerotech apparently burned, but not fast enough to bring the pressure inside the casing up to normal operating pressure before the heat leached away into the motor's casing. The Cessaroni motor on the other hand uses a thick plastic, instead of a cardboard, liner so the heat was retained until the pressure in the chamber increased enough for the motor to start operating at normal internal pressure.

I'd suggest adding a large pressure tank between REHAB and the vacuum pump to maintain the low pressure inside the chamber once the pump is isolated. In addition I would look into adding a burst diaphram to the motors. A simple disk of copper or aluminum made from 0.002" shim stock, with a hole just large enough for the igniter, could be added to the Aerotech motor between the nozzle and the propellant grain for example. You could also experiment with a smaller nozzle on the Aerotech motor. I would contact Aerotech and ask Gary Rosenfield if you could obtain a number of un-drilled nozzels for the 32/60 reload casing. I'd start by reducing the nozzel's exit area by about 50% and then proceed based upon tests in REHAB.


Kenneth G. Holloway

Study reveals high price of porn addiction


From the article:

"surveyed 800 habitual online smut viewers and found “excessive users had severe social and relationship problems and had often lost their jobs or been in trouble with the law as a result of their addiction."

This is questionable science. In the first place how were the subjects selected? I find it hard to believe that a truly representative sample population could be obtained since I wouldn't expect that many smut viewers without problems would volunteer to be studied.

Second the conclusion apparently being drawn is that excessive viewing of smut results in severe social, relationship, and employment problems. It is just as likely that having such severe problems resulted in the excessive smut viewing as a distraction from reality.

This kind of bogus science shouldn't be taken as gospel. Sometimes scientists have personal axes to grind just like laymen.


LOHAN to straddle meaty titanium rod



Just some suggestions based upon two decades of launching model rockets.

(1) The plate and guide rod assembly should be re-thought. When LOHAN's motor ignites the exhaust gases will impinge on the plate and "splash" in a 360 degree arc. The plate needs to extend forward 5 or 6 centimeters to prevent the exhaust gases from cutting the truss.

(2) The rubber bumper also needs to be relocated. If the base of the LOHAN is sitting on the plate at ignition it could be burned and/or twisted around the rod by the exhaust gasses. Moving the rubber bumper out to the rod would prevent the exhaust having any affect on the vehicle.

(3) I'm not sure that LOHAN would slide off the launch rod in the event of a balloon failure. If the remains of the balloon exert any drag on the truss it would probably not rotate downward enough to release the air frame. I'd suggest incorporating a device to initiate the launch sequence in the event of a balloon failure. This should allow the LOHAN to separate from the truss and be recovered normally.

(4) Also why use a titanium guide rod? Aluminum rods and rails have been in use for many years when launching model rockets with no reported problems? Does the titanium have any benefits over the use of a polished aluminum rod?

Kenneth G. Holloway

It's the ALL NEW FUTURISTIC WEAPONS Black Friday Roundup!


New Tech That's 50 Years Old

I was very happy to note that David Dardick's plastic ammo / circular chamber firearms design has finally been recognized as a superior technology by the military. I was fortunate enough to fire one of the 9mm pistols he manufactured as a teenager in the 60's. The actual patents for his system were issued in 1958 so it only took 53 years for the military to adopt his ideas!

Ken Holloway

US doctors demand right to advise on gun ownership


Corrections to Statistics & Statements

I'd like to make a few corrections to the numbers and statements published in the original article.

First the "guns are 43 times more likely to kill a family member than a criminal" is a severely twisted statistic. Most encounters between armed citizens, both inside and outside the home, never escalate to the point of having to fire a weapon. Almost 99 times out of a hundred just displaying a weapon is sufficient to stop a crime in progress. No one would advise a home owner, for example, to kill any intruder he found on his premises. Yet this is what the original statistic is measuring. How many criminals are killed by legally armed citizens versus how many suicides and accidental deaths occur.

Secondly as I recall from newspaper articles the problem was not that Doctors were asking about gun ownership. It was that some were refusing to treat patients unless they disclosed their ownership or lack there of. Some doctors were also reportedly refusing to treat patients if they owned guns and others were threatening to report gun owning parents for child abuse unless they agreed to dispose of their guns.

In America gun ownership is a right that should not be questioned by health professionals without overriding reasons. And that is just what the Florida law does. It only allows Physicians to inquire about gun ownership if there is some medical condition that would affect such ownership, i.e. bad eyesight, mental health etc. Unless some such condition were present Doctors would be forbidden to discuss it with their patients.

K. G. Holloway

So, what's the best sci-fi film never made?


"Rama" Definately

Here is a copy of my e-mail on this subject:

I'd say the best would be "Rendezvous With Rama" without a doubt.

Other overlooked books that I'd like to see made into a movie:

Tom Godwin's "The Survivors" and "The Space Barbarians"

This could be great without being too expensive. CGI effects could be limited on planet to the animals; Unicorns, Mockers, and Prowlers. The animals are what make to books so fascinating. The telepathic Mockers, the insanely murderous Unicorns, and the Hell Hound rejects, called Prowlers, would make this movie great.

Isaac Asimov's "Lucky Star" Novels

Just think what Hollywood could do with a 22nd Century Interplanetary / Interstellar "James Bond" working for the "Council of Science".