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jetZILLA  A P R I L / M A Y   2 0  0 3   E D I T I O N  -
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jetZILLA Online Magazine of Amateur Jet Propulsion Development
    © 2003 Cottrill Cyclodyne Corporation
       [a free subscription e-magazine]
Issue 2003-0508-0103-00                       May 8, 2003
Approx. circulation: Unknown
Publisher:  Larry Cottrill, Cottrill Cyclodyne Corporation, 
                Mingo, Iowa  USA   50168-9500
                email: jetZILLA@cottrillcyclodyne.com
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Welcome, everyone!

I N   T H I S   I S S U E . . .
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1. FEATURE ARTICLE ...
   Real Jets, Real Cheap - 
   20th Century technology on a 19th Century budget
   - Part I 
   - Part II
   Interviews with Mike Kirney and Mark Thixis

2. VERY SPECIAL OFFER! From a friend of jetZILLA ...
   Get Your Copy of Original Lockwood Research Paper 
   - a 'must have' for valveless pulsejet hobbyists!
   offer by Ben Brockert

3. FROM THE MONSTERS GALLERY ...
   Proposed design for Reciprocating Valveless Pulsejet Engine 
   by Larry Cottrill

4. PRODUCTS AND STUFF ...
   Products, links, ads, etc...

5. COMING IN THE NEXT REGULAR EDITION ...
   > Metals in Pulsejet Interiors -
     Destructive Tests Reveal the Truth!

6. ALL THAT BOILERPLATE ...
   Who we are, Subscribe, Unsubscribe, Privacy, etc...

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 F E A T U R E   A R T I C L E  [t w o   p a r t s] . . .
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Next   Contents   Top   Subscribe Now

Real Jets, Real Cheap - 
   20th Century technology on a 19th Century budget 
   [Part I]
   Interview with 'Tundra Man'
_____________________________________________________

Note from the Editor:

Many hobbyists are first attracted to pulsejets because of their 
seemingly cheap and simple construction.  These people are then 
shocked when they peruse the Web and find jets on E-Bay costing 
hundreds of dollars. Although Bruce Simpson's advanced designs 
and David Brill's zinc castings are beautifully designed objects, 
they might be considered too pricey for the average backyard 
experimenter. Two regular participants at Kenneth Moller's jet 
propulsion forums have found some solutions for the penny-pinching 
powerplant designer. Read this and the following interview to find 
out how they managed to build some astounding machines on some 
astoundingly thin budgets.  - Larry Cottrill
_____________________________________________________

The Tundra Jet
['Tundra Man' Mike Kirney, interviewed by Larry Cottrill]

The first jet project in our 'Cheapskate Homebrew Showcase' comes 
from Mike Kirney, of Renfrew County, Ontario.  He is known to 
many on Kenneth's forums as "Tundra Man".  After reading and 
posting on the forum for over two years, he finally decided to 
take the plunge and build himself a 1/3rd scale Argus 014 replica. 
[Editor's note: The Argus was the engine which powered the famous 
V-1 "Buzz Bomb" which Germany used against Great Britain in World 
War II. Though primitive by today's standards, the V-1 can 
probably legitimately be considered the first production "cruise 
missile" ever launched.] According to Mike, The only materials he 
purchased for this working model were a 3 x 6 foot piece of 22 
gauge steel sheet, a 6 by 50 inch roll of  0.005" stainless steel, 
and two rods, 1/8" x 36" [one cold rolled steel, and one brass] -
and ended up with more material left over than what he used for
his engine!

Our interview with Mike took place a few weeks ago [mid-April,
2003] - here's what he had to say about building his mini-Argus 
engine:


    

      

	
		
      
      

	ALL  WELDED  UP  AND  NO  PLACE  TO  GO
		
The fully welded tailpipe assembly of Mike Kirney's
		
'Tundra Jet'. The square plate at the top end of 
		
the pipe in this photo is the not-quite-finished
		
'front plate', which provides the mounting surface 
		
where the valve plate will ultimately be attached.
		
Photo Copyright 2003 Mike Kirney
		



		

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jZ: Welcome, Mike! All right, let's get started. How did you 
first become interested in pulsejets?

Mike: Back in '99, I was an aircraft maintenance student in 
community college.  A passing mention was given to pulsejets in 
my powerplant textbook.  Although the text claimed that the 
pulsejet had no practical value as an aircraft powerplant, the 
idea of producing hundreds of pounds of thrust from a simple duct 
and valve device captivated me. I had no idea how they worked or 
what sort of operational idiosyncracies they presented until I 
found Kenneth's forum online, a year later.

jZ: How much have you spent on materials for your first engine 
project, the 'Tundra-Jet'?

Mike: The steel sheet was $40 CDN, the roll of stainless shim was 
$30 and the rods were seven bucks each, for a grand total of $84 
CDN. I still have more than 2/3rds of the sheet left and about 
4/5ths of the roll of shim.  If I bought just a couple more rods, I 
could make at least two more Tundra-Jets from the leftover 
materials.

jZ: Tell us about the design of this pulsejet.

Mike: I decided to shoot for a duct length (behind the valves) of 
100 cm.  I just divided all the dimensions of the original Argus 
by 3.3 - many forum members advise against such a simplistic 
approach but it seemed to make the most sense to me.  I wasn't 
looking to make a lot of thrust, as I intended to use my jet for 
melting snow in my driveway, plus, by adding length to the 
tailpipe, I can change the operational characteristics.


    

      

	

	  
HANGING  LOOSE
		
An early shot of Mike's beautiful hand-formed pipe 
		
sections, carefully stacked together before any 
		
welding. This does indeed look almost identical to 
		
the original Argus engine pipe -- only the scale of
		
surrounding objects reveals the truth.
		
Photo Copyright 2003 Mike Kirney
		



	  
	  

		

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jZ: What about the valve-holder? I know Your intake is a sort of 
square steel frame 12 cm on each side, enclosing a grid of 
more-or-less square cells to contain the reeds.

Mike: The valve array took the most work to design.  I figured my 
jet was too big for petal valves.  Had I used them, each petal 
would have wound up being almost 7 cm long!  I wanted to use the 
22 gauge sheet for as much of the jet as I could.  Eventually I 
devised an interlocking set of 10 steel rectangles with tabs and 
slots cut in them.  The horizontal pieces have two holes drilled 
in them, one behind the other, to form a figure-8.  I cut pieces 
of steel rod 14 cm long and knocked them into the rear-most holes.  
These rods I brazed in place.  They serve as the permanent half 
of valve holders.  After placing the reeds in their respective 
positions, I then knocked the brass rods into the front holes.  
The valves are thus held in place between the two rods, the brass 
ones easily removable with a punch pin for reed replacement.

jZ: How will you keep the brass rods in place? I mean, I can
see vibration gradually working them loose, or something.

Mike: I think I'm going to lash them to the steel rods with wire 
at each end and then tin solder it all in place. The solder can be
easily removed for maintenance.


    

      

	
		
      
      

	

	  

	    

	      A  THOROUGH  GRILLING
		
The pieces of the valve grid, carefully set up
		
before brazing it all together. The steel rods are 
		
vertical in this shot; the brass rods aren't in 
		
place, but would be hidden behind the steel rods.
		
One folded reed will form a back-to-back pair of 
		
valves in each cell.
		
Photo Copyright 2003 Mike Kirney
		


		

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jZ: What did you have to do to actually fabricate your reeds?

Mike: I cut them from the 0.005" stainless shim with ordinary 8 
inch long scissors.  Each rectangular reed is 6 cm long and 1.5 
cm wide.  These pieces are bent in the middle so that they rest 
like saddles on the steel rods in the array.  Each reed 
effectively becomes two valves when the brass rods are hammered 
into place.

jZ: OK -- let's make sure I really have an accurate mental picture
of this. We have a steel rod permanently set. Each valve reed is a
rectangle folded in the middle to form a V-shaped piece. The point
of the 'V' rests against the rear side of the steel rod, then the
brass rod is slid through behind - or inside - the 'V' to lock it 
against the steel rod in front.

Mike: That's it.

jZ: How did you handle the hot metalwork?  I believe you've said 
you used conventional torches to do the brazing and welding.

Mike: Yes, I did.  The first thing I did was clean an area of the 
steel sheet with varsol and acetone to get all the grime off. 
Then I sprayed it with a light coat of grey automotive primer. 
This allowed me to draw easily visible lines on it with an HB 
pencil. I used a ruler and a triangle to lay out two rectangles, 
which I cut out with a pair of compound leverage shears.  After I 
removed the primer and pickled the pieces with muriatic acid,  I 
washed them with dish detergent and water and rolled them by hand 
into cylinders which would become the combustion chamber and 
tailpipe of my jet.  I used an oxyacetylene welding torch to do 
all the welding and brazing and some of the cutting.


    

      

	

	  

	    
A  BRAZEN  ATTEMPT ...
		
Here's the grid after brazing all the connection
		
points. Brazing is not necessarily beautiful in its
		
finished state; the technique is similar to silver 
		
soldering, but at a higher temperature. It is quite
		
strong, though not equal to welding.
		
Photo Copyright 2003 Mike Kirney
		


	    
	  
	  

	    

		

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jZ: But you cut the sheet metal with hand shears ... wow.
Weren't the cut edges awfully rough and distorted?

Mike: Yes, they were.  I cut all my pieces a millimetre or two 
oversize and then I filed the edges down to the pencil lines with 
a 9" bastard file and an 8" mill file.  The shearing and filing 
took the most physical energy of all, especially the shearing.  
Sometimes I had to brace the shears on my basement floor and step 
on them to make the cuts, especially when I was deep into the 
material.

jZ: You said you rolled your pieces by hand?  Surely you must have 
used implements of some kind ...

Mike: I did.  I used 4" lineman's pliers to bend one edge of the 
rectangle downwards slightly.  Then I placed two 1" dowels, one on 
either side of the bend and curled my fingers around the inside 
dowel.  I just rolled up the steel like a piece of paper.

jZ: Like a piece of paper ... hmmmm, right ...

Mike: Well, that's how I got the first edge started anyway. I used 
a variety of techniques to form the cylinders. In my mind's eye I
would break up the circumference of the cylinder into quadrants. 
I would alternate quadrants, clamping the sheet between the dowels 
and bending one quadrant in a little, then the other, all the way 
around, until the edges to be butted were about 5 - 8 mm apart. 
Then I rolled the bent edge under the flat edge and presto, I had 
rough cylinders.  I used a bit of 1/4" rope as a way to apply
uniform pressure to cinch the edges together too.


    

      

	
		
      
      

	FIRST  TRY  AT  WELDING
		
Another picture from very early on in the project: 
		
The combustion chamber cylinder, with Mike's first
		
weld [well, the first in a long time, anyway]. Looks  
		
awfully good to me.
		
Photo Copyright 2003 Mike Kirney
		



		

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jZ: Was it difficult to weld your cone and cylinders?

Mike: I did practice a little before I started - it was the first 
time I had picked up a torch since college. I used a #0 tip and 
about 4 psi on the acetylene. My oxygen regulator was designed 
for cutting so it was hard for me to tell just how much pressure 
I had in the hose.  I estimate about 7 or 8 psi. I used 1/16" 
mild steel rod for the welding and 3/32" flux-coated brass rod for 
the brazing.

jZ: With a higher oxygen pressure like that, I'd guess you must 
have blown through a few times!

Mike: Not really. First I put a tack weld every 12 cm or so down 
the length of the piece. Then I heated the rod just enough so 
that it would get droopy and stick to the edges to be welded.  
After I had laid down a few inches of rod this way, I would go 
back and puddle it all together with the base metal. The biggest 
problem I had was my workpieces warping and the edges overlapping, 
especially with the long tailpipe. This really freaked me out at 
first, but in the end it all turned out okay. After welding, I 
shaped the cylinders a little more by hammering them over a scrap 
piece of wood and squeezing them in my hands and between my knees.

jZ: What about the cone?  A lot of people think they know how to 
lay out a cone, but then after they roll it together and weld it 
up, they find out they were way off the mark!

Mike: That nearly happened to me. Thank God for Hank bringing it 
up on the forum. It was his fortuitous comment that made me 
realize that I had no idea how to lay out a flat pattern for a 
truncated cone. I did a websearch and found a site with a really 
good method based on trigonometry. Using that method, I made a 
template which I traced onto a piece of cardboard. Then I traced 
that onto the steel sheet. I refined their explanation a little 
and put it up on my webspace:

          http://home.ca.inter.net/mkirney/cone.html

jZ: Why didn't you just use the well-known program called "Cone"?

Mike: I thought about it, but I realized that my developement 
would be too big to print on a single sheet of letter-sized 
paper.  Believe it or not, I actually enjoy doing trig.  I wanted 
to learn the principles behind the cone development so I could 
apply them to other shapes as well. 

jZ: You ENJOY trigonometry?  Are you psychotic, or what?

Mike: Well, lets just say I am socially functional but as yet, 
psychiatrically undiagnosed.

jZ: How can you enjoy trig?  Seriously, Mike ... I detect 
illness ...

Mike: Hey c'mon Larry. I don't make fun of your little tiny jets.

jZ: Tiny? TINY!!! My engines will ... uh ... fit into any budget
and lifestyle ... they'll uh ... become a novel addition to any 
home environment ... um ...

Mike: Yeah, right ... well then, just cut the jive about my trig 
fetish, OK?

jZ: Oh, all right, we'll try to get back on topic here. You 
mentioned to me earlier that you actually did some cutting with 
the welding torch. Isn't that ... illegal or something? [laughing]

Mike: Nope. I used a #2 tip to cut out the circles for the 
valveplate and the frontplate on the duct. It was very quick and 
easy but I had to file off the inside edges afterwards.  

jZ: Yes, actually my dad had a rather nifty trick for that. He'd
heat a spot up red hot with the torch, then quickly valve off 
the acetylene and just start moving it along, letting the oxygen 
stream keep the cut going. It was an amazing thing to see! Now,
you have a frontplate that acts as a mounting surface for your 
valveplate, right? That's pretty heavy stuff compared to the 
sheet metal chamber -- I mean, welding the frontplate to the 
combustion chamber must have been a bit of a blacksmith's 
nightmare, I would think.

Mike: Nah, it was easy. I used the same technique as before 
where I laid down the rod and then puddled it after. There was 
some overlap left on the inside of the hole so I just  puddled 
that down to a nice round edge. That joint is probably the 
strongest one on the whole engine.

jZ: How do you attach the valveplate to the rest of the jet?

Mike: I use eight 5/16" bolts with nuts and lockwashers.  They 
are about an inch long so they should accomodate any gasket I might 
have to use.

    

      

	

	  

	    
TAKING  THE  LONG  VIEW
		
Looking rearward through the fully welded engine,
		
as seen through the mounted valve plate grid. Note 
		
the slight out-of-round distortion -- while almost 
		
inevitable when fabricating all the parts by hand, 
		
this should have absolutely no effect on running 
		
or performance.
		
Photo Copyright 2003 Mike Kirney
		


	    
	  
	  

	    

		

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jZ: So ... when do we get to hear this beast run?

Mike: Well, the chinook just blew through town today so that 
usually means we're gonna get one more snowfall this week, then 
the frost is over until Hallowe'en. I'm hoping I'll have 
everything good-to-go by the end of April. I'm trying to adapt a 
fuel system from a 1 lb. propane bottle and an old welding torch 
I found in my shed. I have an old regulator too. I'm thinking 
about just using fireplace matches to light the thing, as 
electric starting seems kind of decadent right now.

jZ: Oh, before I forget ... thanks for getting an interview for us
with our friend, Mark 'Thixis'. I'll try to publish that right along
with this one.

Mike: Yeah, Mark's always fun to talk to -- and that dude really
builds some weird stuff ... he gets it to run, though!

jZ: Well I hope you keep in touch, Mike.  I mean, we're going
to be hanging from the rafters by our fingernails waiting for your
test results!  The Tundra-Jet sounds like it's bound to cause a shop 
class revolution.

Mike: [laughing] Ha! Shop class revolution -- I could really dig that! 
Thanks for interviewing me, Larry. Hey man, I saw some empties under 
your front deck. Would you mind...?

jZ: What, those old Pepsi cans? Uh, yeah, whatever ... go ahead 
and take 'em.

Mike: Thanks, man ... you just never know what you can use. See,
I just now thought of this little jet where you'd ...

_____________________________________________________

Photo Credits:
All photos in this article were provided by, and are property of,
Mike Kirney.
_____________________________________________________

Mike Kirney, of Renfrew County, Ontario, Canada has been interested in pulsejets for several years, but only started to build his own a few weeks ago. Mike has also played guitar [the instrument shown here is a Godin electric from Quebec], piano, flute and alto sax. He has visited all ten Canadian provinces and about 20 States of the US, and once bicycled from Vancouver, BC to San Francisco, CA in nineteen days. He is very interested in alternative power sources, especially some new uses for steam. Mike answers to the nic "Tundra Man" and can be reached at ame2000@lycos.com Photo Copyright 2003 Mike Kirney

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Next   Contents   Top   Subscribe Now

Real Jets, Real Cheap - 
   20th Century technology on a 19th Century budget 
   [Part II]
   Interview with Mark 'Thixis'
_____________________________________________________

Note from the Editor:

There's more than one way to build working pulsejets 'on the
cheap'. In the previous article, Mike Kirney showed how low cost
materials can be used effectively; however, Mike's building
techniques still require a lot of manual skill and effort - 
especially, skills in metal forming and gas welding. The
following article shows a completely different method. This 
does not produce lightweight 'flight engines' [which is what a 
lot of us kind of expect a jet engine to be] but rather, simple, 
extremely rugged structures, built mostly of ordinary plumbing 
parts -- what this builder calls a 'Tinker Toy' approach. As 
you'll see, it's something really different!  - Larry Cottrill
_____________________________________________________

Welding? Who Needs Welding To Build a Jet?
[Mark 'Thixis', interviewed for jetZILLA by Mike Kirney]

Here's the other entry in our 'Cheapskate Homebrew Showcase':
Mark 'Thixis', another participant on Kenneth Moller's 
pulsejet forum, has constructed an amazing array of simple 
pulse combustors using only inexpensive steel pipe and cast 
iron plumbing parts, mostly without precision machining. Mark
lives in the State of Florida, USA. Here he's interviewed for
jetZILLA by Mike Kirney [see my interview with Mike, above] 
and answers some good questions for amateur pulsejetters:

jZ: How's the weather down south, Mark?

Mark: It's great, Mike!  The Spanish Moss is hanging long and I 
can eat my fish now instead of running my sled on it.

jZ: Uh ... I beg your pardon?

Mark: Read my forum posts -- you'll figure it out.

jZ: Um, OK ... I'll do that. You have quite a collection of 
homemade jets. How long have you been experimenting with pulse 
combustion?

Mark: I have been doodling with pulsejets for about 15 years.


    

      

	
		
      
      

	

	  

	    

	      THE  'THIXIS'  FAMILY  PORTRAIT
		
Except for the original DynaJet [the 
		
engine with the red anodized valve head, 
		
near the center of the photo], all these
		
are experimental engines and 'jam jar'
		
combustors Mark has built or modified 
		
from such things as plumbing hardware
		
and medical implements [and, in some
		
cases, even glass jam jars!].
		
Photo Copyright 2003 Mark 'Thixis'
		


		

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jZ: Wow! That's a lot of experimental experience. What got you 
interested?

Mark: Long ago my brother gave me a Dynajet that he bought in 
Texas for around $60.00. I didn't fire it up for several years. 
Then I did, and was surprised at the noise. Later, in college, 
I started to wonder if I could build one out of water pipe, and 
it took me a few months of thinking and toying until I got one 
to run. 

jZ: What's the biggest jet you've ever built?

Mark: The biggest jet I attempted was a 4 inch plumbing pipe 
which weighed over 40 pounds and was a beast which shook my 
garage wall, along with all the things hanging on it, when it 
fired. I cowered and decided the neighbors would complain if I 
kept the cannon shots up.

jZ: Man! You're lucky you didn't get busted! Did it sustain 
combustion?

Mark: No, the biggest I've gotten a continuous run from is 
three inch diameter [75mm ID], thick-as-can-be threaded 
water pipe.


    

      

	

	  

	    
MARK'S  BIG  IRON
		
This is the 3-inch pipe engine 
		
mentioned above. The valve plate
		
shown in this month's cover photo
		
and in the photos below are from 
		
the front end of this engine, and
		
can be seen from the valve side at
		
the center of this shot. The reddish 
		
object is the valve head of the
		
DynaJet, shown here for scale.
		
Photo Copyright 2003 Mark 'Thixis'
	    
	  
	  

	    

		

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jZ: What fuel do you use in your jets?

Mark: I like to use methanol. It evaporates quickly and is very 
forgiving with fuel/air ratios.

jZ: Tell me about your first jet. How much did it cost?

Mark: My first jet cost me about $10.00 in parts if you don't 
count the spring steel, which was about $20.00 a roll, but you 
can make a lot of reeds out of it.

jZ: A jet for thirty bucks US!  What tools did you use to build 
that thing?

Mark: The tools I used were a grinder, drill press, vise, pipe 
wrench, and a tap for the spark plug. A very smooth edge can be 
made on a valve plate by inserting a bolt in the middle of the
plate and rotating the disk against an edge in order to control 
the distance.


    

      

	
		
      
      

	

	  

	    

	      A  PLATEFUL  OF  HOLES ...
		
Mark's 'bench grinder machined' valve plate at the 
		
bottom, with the fuel port assembly, built up out of 
		
hardware store plumbing parts, bolted to the center. 
		
The ring of nine holes in the plate lets air/fuel mixture 
		
into the combustion zone when suction opens the thin 
		
spring steel petal valves [see bottom view, next photo].
		
Photo Copyright 2003 Mark 'Thixis'
		



		

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... AND  A  FLOWER  OF  NINE  PETALS
		
Here's the valve plate back side, with the 
		
nine valve petals clamped in place under the 
		
retainer [the large washer in the center] --
		
the central bolt not only holds the retainer,
		
but goes clear through the plate to support
		
the fuel port assembly shown in the photo
		
above. The front side of the retainer is 
		
dome-shaped to allow the petals to open 
		
rearward and land on its smooth surface.
		
Photo Copyright 2003 Mark 'Thixis'
		

	    
	  
	  

	    

		

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jZ: Thanks for the 'machining' tip, Mark. The classic 21st Century 
pulsejet is fabricated from thin guage stainless steel sheet. The 
heat produced by operation can make these glow brilliant orange.  
Does the thick steel wall of the plumbing pipe glow ever like that?

Mark: Even though they are very thick, they glow a dull red, and 
if mounted on a board with nails to wedge it down, the board will 
billow smoke from the heat.

jZ: Sounds dangerous! What about the zinc coating? Most plumbing 
pipe is galvanized, is it not?

Mark: It is. Once I found a deposit at the tail of a 3 inch 
diameter water pipe jet. It had formed or melted a ring of zinc 
or something that I pulled out almost in one piece from the 
galvanized plumbing pipe after it cooled down. I had previously 
attempted to grind a flare in the tail [which didn't work with my 
tiny grinding stones] so I know the ring wasn't there to begin 
with. The ring of metal was soft and bendy. 

________________________________________________________________

CAUTION! Precautions need to be taken when using galvanized or
cadmium plated steel in a pulsejet. When the steel gets red hot, 
the galvanizing or plating will start to burn off -- the 
smoke-like fumes from this are EXTREMELY hazardous to breathe. 
When welding such materials, always provide adequate air 
movement to keep these fumes away from your face [a small 'box' 
fan is adequate] or better yet, work outside and orient the work 
so the breeze immediately blows the fumes away from the weld 
area. When running your jet the first few times, stay on the 
upwind side so the smoke and fumes aren't blowing toward you. 
When the engine has been hot enough long enough, the galvanizing 
or plating will be completely burned off, so this hazard is 
eventually eliminated. - Editor
_________________________________________________________________


    

      

	
		
      
      

	

	  

	    

	      NOW,  A  FEW  SHAMELESS  PLUGS
		
Mark's collection of ignition plugs that  
		
he's used in various homebuilt engines. 
		
Note that some of these are extensively  
		
modified! [The three little plugs at the
		
left edge are model airplane glow plugs,
		
for scale. In general, little success has
		
been achieved by anyone trying to use 
		
glow plugs for pulsejet ignition.]
		
Photo Copyright 2003 Mark 'Thixis'
		


		

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jZ: What's the longest one of your jets has actually sustained 
combustion?

Mark: The longest I ever ran one was for about 5 minutes, when I 
decided to go ahead and let it run the tank dry.

jZ: That's a pretty decent run, as far as I can tell.  Thanks for 
dropping by to answer some questions for JetZILLA, Mark.

Mark: No problem, Mike. Hey buddy, do you have another beer?

jZ: More beer? Who do you think I am, Molson Breweries? Get outta 
here!

Mark: OK, OK. Um ... would be it be alright if I left my truck 
here overnight? 


    

      

	
		
      
      

	

	  

	    

	      RUGGEDER  THAN  YOUR  AVERAGE  JAR
		
One part of Mark's pulsejet hobby is making up
		
'jam jars'. A jam jar is an 'almost pulsejet' which 
		
sits upright with a small pool of liquid fuel at 
		
the bottom, and runs by alternately firing and 
		
breathing through a single small nozzle at the 
		
top, after lighting with a match. Traditionally, 
		
jam jar engines are made from a small glass jar
		
[or more recently, plastic bottle] with a metal
		
lid in which a small hole has been drilled or
		
punched. Mark likes his a little heftier; the 
		
ruler on the left is a six-inch [approx. 16 cm]
		
rule.
		
Photo Copyright 2003 Mark 'Thixis'
	    
	  
	
      
    

_____________________________________________________

Photo Credits:
All photos in this article were provided by, and are property of,
Mark 'Thixis'.
_____________________________________________________

Mark 'Thixis' is a longtime pulsejet builder and experimenter
living in Florida, USA. No one knows what his last name really 
is, and nobody knows what 'Thixis' really means. But, if you 
want to contact him about this article, email: Thixis@aol.com
_____________________________________________________

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HELD OVER FROM OUR LAST ISSUE!

 -   V E R Y   S P E C I A L   O F F E R   -

 F R O M   A   F R I E N D   O F  jetZILLA  . . .
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Get Your Copy of the Original Lockwood Research Paper
   - a 'must have' for valveless pulsejet builders!
offer by Ben Brockert, pulsejet hobbyist
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We introduced this offer from my friend Ben Brockert last month. He has
discovered an early copy of the original paper on the Lockwood design, 
prepared for Hiller Aircraft by Ray Lockwood, who was employed by 
Hiller in the 1960s, and is making new copies available to any pulsejet
hobbyist who wants one. I have obtained my copy from Ben, and it is a 
wonderful paper, not overly mathematical, with an excellent description 
of the theoretical and practical advantages of valveless pulsejet 
designs, and of the Lockwood design in particular. It includes some 
performance related graphs and other research data. For anyone
interested in valveless pulsejet theory, this is an unbelievable bargain
for your two bucks (payable through your PayPal account). Ben says:

  In my continuing search for knowledge from the first era of pulse 
  jet research, I recently found a copy of an interesting document. 
  Written by R. M. Lockwood in 1964 and entitled "Pulse-Reactor Low 
  Cost Lift-Propulsion Systems", it includes the basic theory of 
  operation of the Lockwood valveless pulse jet; as well as 
  experimental data on augmentation, fuel efficiency, and noise 
  reduction.

  I'm offering copies of this paper for $2(US)/each, with all proceeds to
  be used in future searches for more documents. Details can be found on 
  my web site at http://www.hepjet.com/docs/


My advice is, DON'T pass this up -- GET YOUR COPY NOW!

- Larry Cottrill
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 F R O M   T H E   M O N S T E R S   G A L L E R Y . . .
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Note from the Editor:

In this feature of each issue, we'll feature one of my own
designs from our Gallery of Hopeful Monsters. These
will generally be jet engines or related equipment that are
PROPOSED designs that are as yet untested and unproven --
BUILD AT YOUR OWN RISK !!! No full-size plans, scale prints
or detail drawings, other than what we show here, are available.
Also, since these are usually just proposed designs that we haven't
even built ourselves, we offer almost no technical information --
these are definitely for advanced experimenters who are used to 
working out the fine points on their own!

So, these designs are mostly presented to give you something to
think about, although advanced hobbyists can try to build them
and get them to run. Let us know if you have any amazing
successes to report!

One of my latest designs, from August of last year, was this
'double barreled' design for a 'reciprocating' pulsejet engine
where each side would assist the other by alternating passage
of blast gases into the chambers, at the same time assisting air
induction via ejector action.

Hope you like it!  - Larry Cottrill
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Proposed design for Reciprocating Valveless Pulsejet Engine 
   by Larry Cottrill
Copyright 2003 Larry Cottrill


    

	

		
	

		VIEW LARGE
IMAGE  
    
RECIPROCATING EJECTOR VALVELESS ENGINE
The original concept drawing, as disclosed on 07 August 2002. The engine is designed 
to be fabricated entirely from flat and bent sheet metal, without rolling.
Drawing Copyright 2002 Cottrill Cyclodyne Corporation


Original disclosure 08/07/2002 on Kenneth Moller's Valveless Pulsejet Forum, 
as follows:
[
Gentlemen - 

Yesterday I saw Eric's thread on the Pulsejet Forum and took a look 
at his marvelous renderings, including his 'alternating valve' job -- 
that led me to think of this valveless reciprocating alternative. This 
is not quite like the E-P, but is linked at the front end, where the 
crossover exhaust can drive an ejector to boost the flow into each 
intake. 

The idea is to build it with flat plates for side walls and variously 
bent plates for the pieces seen in section in the drawing (it would be 
a good project for Ben, who does a lot of sheet work WITHOUT rolling). 
The 'baffles' at the rear are to keep each exhaust stream from unduly 
influencing the other half (a la Esnault-Pelterie). 

Let me know what you think ... 

L Cottrill
]


Theory of Operation

When the explosion of the air/fuel mixture occurs in one of the
combustion chambers, some of the blast product gases are driven 
forward and funneled into the wide, shallow ejector channel. The
channel turns the gas backward and into the front ejector section
which forms the intake throat to the alternate chamber. Ejector
action helps draw fresh air into that chamber, where it mixes 
with the fuel entering via its continuously-running fuel injection 
nozzle. When the proper ratio of air to fuel is reached, the next
explosion in that chamber occurs, reversing the process.

By the time the hot gas from the latest explosion reaches the 
alternate chamber, exhaust gases have almost entirely left the
alternate combustion chamber, leaving it in an over-expanded,
low-pressure state. The combination of outside air pressure in
front of the intake and the ejector action of the blast gas
entering the intake throat area should provide very rapid filling
of the alternate chamber, to set it up for the next explosion.
Also, the hot gas from the ejector channel should aid in getting
prompt ignition when a good air/fuel ratio is reached.

Note that some ventilated air space should be left between the two
exhaust ducts -- attempting to merge them together as a single plate
will almost certainly cause severe erosion of the material due to
total lack of air cooling.

If you decide to try to build a working model of this experimental design,
make sure you get plenty of photos and email them to us in GIF or JPG
format to display in a future issue [we will make the final decision 
as to the best ones to use, and we'll show your name as a photo credit.] 
And, why not try writing an article about building and firing it? We 
don't pay for articles, but we'd be glad to help you "get your name in 
print". Also, any author whose article we accept gets a free ad for your 
e-business or Web site! Naturally, we will provide editing as needed for
publication in readable US English. 

- Larry Cottrill

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P R O D U C T S   A N D   S T U F F  . . .
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__________________________________________
 
V i s i t   O u r   F r i e n d s  . . .
__________________________________________

   Bruce Tharpe Engineering - 8622 E Evans Creek Road, 
      Rogue River, OR 97537  Phone: 541-582-1708. 
      Assembled fuel bladders, pulsejet model plans and 
      MUCH more.   email: tharpe@cdsnet.net
      Site: www.btemodels.com    

   ModelFlight - United Kingdom 
      A top-notch magazine for model flyers -- check out 
      the 'Gallery' section for photos of some absolutely 
      beautiful aeromodeling work from all over. Lots of 
      scale stuff. Good construction hints, reviews, etc. 
      All kinds of aeromodeling represented, including the 
      occasional jet craft. www.modelflight.fsnet.co.uk    

____________________________________________
 
V i s i t   O u r   O w n   L i n k s  . . .
____________________________________________

   Tools for Marketers / Webmasters [ TfMW ] -
     Page 2 [ complete product catalog ] - 
      www.cottrillcyclodyne.com/NetProd_page2.html    

   Cottrill Cyclodyne SFOATM Pulsejet Engine Design / 
      Development Page - where "Steel Floats On Air"!
      www.cottrillcyclodyne.com/SFOA1.html    

   Cottrill Cyclodyne Corporation Site Directory - 
      www.cottrillcyclodyne.com/Page_9999.html    

   jetZILLA Initial Press Release [ return to the 
      jetZILLA home page, then select from 'Archived 
      Editions' ] - 
      www.jetzilla.com    

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M a k i n g   M o n e y   o n   t h e   'N e t  . . .
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   Push Button Publishing - 
      Bryan Winters promises: "Not Only Will I Show You
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C O M I N G   I N   T H E   N E X T   E D I T I O N . . .
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   > Metals in Pulsejet Interiors -
        Destructive Tests Reveal the Truth!

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A L L   T H A T   B O I L E R P L A T E . . .
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W h o   I n   t h e   W o r l d   A r e   W e ?
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Larry Cottrill with ReynstodyneTM SharkTM engine prototype after
		early test firing
Photo Copyright 2003 Cottrill Cyclodyne Corporation
    


My name is Larry Cottrill. I'm Director of Product 
Development and Acting CEO of Cottrill Cyclodyne 
Corporation, registered as a for-profit corporation in 
the State of Iowa, USA. We are striving to create the 
world's smallest, safest and most practical hobby jet 
engines. We also have an intense interest in Internet- 
and Web-based marketing [since our future products 
will be promoted and marketed extensively online] and 
offer top-quality, low-cost and no-cost resources to 
help make the jobs of marketers and webmasters easier, 
more cost-effective and more productive.
 
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