Bumbling around the internet this afternoon, I found this link to a Mechanix
Illustrated contest to design and build a jet engine. Lots of good ideas in
this scanned article to get started on the competition.
As a kid in the 60's I was really into model airplanes, and had a couple
Dyna and OS Max (if it means anything to anybody) pulse jets, and to
this day think they're responsible for my partial hearing loss... jeez
were they loud, and low frequency loud too. About 440Hz IIRC. I remember
they could literally be heard for miles, and gave my dad nose bleeds.
They liked to go through reed valves... chunks would break off around
the edges of the 'petals', and they'd chew up the aluminum valve seats
in short order.
I think some people still mess with them, engines still show up on eBay
from time to time... a few Dyna Jet's are there now as a matter of fact.
No! And that sounds neat as hell! Got some info?
That rifle hanging on the wall of the working-class flat or labourer's
cottage is the symbol of democracy. It is our job to see that it stays
- George Orwell
Well I was only an onlooker, not a constructor, and it was 50 years
ago, but if I remember right it went like this:
The armorers (it was usually the armorers) would punch the primer out
of the end of a spent .50 cal casing. Then they would drill two holes
into the side about a half inch from the end. One hole was for a model
aeroplane glow-plug, the other a little spigot thingy that had a
tapered needle valve, I think it was from a model aeroplane engine
too. They would saw the neck off the end of the case so a penny could
be dropped inside, and this was pinned in place down at the end of the
case by a piece of twisted monel aircraft locking wire. The penny was
trapped over the primer hole, but not tightly, it was free to rattle
back and fourth maybe 50 thou.
Then the casing was mounted in a vise and fed JP4 through a length of
tubing. The armorer's guncart that was used to prime the Wurlitzer gun
chargers was brought into play to blow a good blast of compressed air
into the end of this diabolical device. A quick check to make sure the
flight sergeant was somewhere else and a battery was hooked up to the
The first result was a lot of flame and smoke and fiddling with the
fuel adjustment, but if you got it right the flame would disappear
inside the case with a pop and drive the penny closed against the
primer opening. The air blast would promptly open it again, then the
exploding air-fuel mix would close it. The rig was essentially a
stationary pulse-jet of the same basic operating principle as the
engine that drove the German V1 "buzz bombs".
I don't think I ever saw one run more than a minute before the casing
Don't ask :-)
Things are actually pretty crappy since the government stepped in to
shut down my activities -- of course it didn't help that I'd
embarrassed them by publicizing the fact that they okayed me to export
advanced jet engine technology to Iran in direct contravention of
treaties that prohibit such things.
No, I had no intention of exporting the technology but I thought I'd
ask -- just for the hell of it and was absolutely gobsmacked when they
said "yes, there's no problem with that, you can go ahead"
That little fiasco and what appears to be a lot of nudging from the US
administration resulted in some rather nasty retaliation that has left
One of NZ's leading news and current affairs programs did a piece on
my situation and it can be seen (Windows Streaming media) at
So right now I'm sharing a rented house with about a dozen rats and
countless fleas while unable to work -- because there's no jobs
matching my skills/experience in this area and I can't afford to move
to a place where there is.
C'est la vie I guess.
you can contact me via
Whatever happened to the great US freedom of speech and the right to
bear arms? (although I suspect that doesn't include missiles :-)
The silly thing is that I had contacted the FBI and DARPA before I
started the project and asked them for their comments. The FBI sent
me an automated acknowledgement of my communication, DARPA ignored me.
I even offered to share all my work and results with DARPA because
they're charged with developing a defense against low-cost cruise
missiles and have a programme in place to do this.
It's a bit harsh therefore, to turn around later and slam someone who
has done their best to inform and seek comment.
What's more, the whole rationale for the project was to make it
*harder* for potential terrorists to build such a device by arming the
public with the knowledge of what such a nefarious group would need
and how they would likey go about the task.
I have never (and never intended) to publish any information that
wasn't already available elsewhere in the public domain or on the net.
Indeed, if you know where to look you can find sufficient in the way
of drawings, plans, pictures and other technical details to build your
own V1. Hell, the US government's own public NACA archives (available
online) contain a *very* detailed technical description and analysis
of the Argus pulsejet engine used on the V1.
The real reason they got snotty was probably because I publicized a
weakness in their defense capability that they really didn't want the
public to know about (although you can bet that terror groups have
known about it for a long time because, once again, it's well
documented on US government websites).
Ah well, that's politicians for you :-(
you can contact me via
Doesn't apply outside the US.
Yeah, but you drew all that information together in one place, and showed
how it could be made to work together, inexpensively. That's 99% of any
engineering design project. It may have seemed an obvious synthesis to
*you*, but to the non-engineer it is an astonishing cookbook. Even to
another aeronautical engineer, consulting the information you correlated
represents a tremendous saving of time, effort, and money.
You might want to consider the fate of Gerald Bull. If the Man considers
you a continuing irritation, assassination isn't out of the question.