Re: [pop-pop-steamboats] Does anybody want to start discussing something?
- Hi Richard,
Thank you for the information about square-tube,
coiled boilers and Kitchen rudders. I know quite a bit
more about methods for improving the performance of
pop-pop engines than I did ten-minutes ago.
One of the best, and currently rarest non popping
pop-pop boats has a similar folded over coiled tube
similar to what you described. Seems a better way to
go about it than a coil of the type shown in most
photos of engines of this kind. One of the items in
files titled "Vertical self-contained pop-pop engine"
shows a less than explanatory view of a vertical
engine sold by Hobbies of Dereham for an outrageously
inflated price. There's a similar vertical engine in a
wooden boat shown in a photo on the website for
"Buzz's Boatyard." I have assumed that both of these
vertical engines use diaphragm boilers, since vertical
coil engines might look more like stacks without
attached "fat" boiler sections. One advantage of thin
vertical boilers might be that they could be installed
in cylindrical versions of the "bait" or "centerboard"
box and rotated for steering, the way outboard motors
are used. I probably have more time to waste searching
for stuff on the WWW and will try to find out more
information of the kind you have provided. I'm
something in between a contributor and a skulker on
the paddleducks group, formerly a Yahoo group, but now
on their own website. Check it out if you haven't
already- very informative and lots of wonderful
Thanks for a lot of information about things I didn't
know about until quite recently!
--- Richard Jenkins <rjenkins@...> wrote:
> Hi everyone,__________________________________________________
> Sorry for the delayed introduction here. I've been
> the list for about a week now, but now I finally
> a little bit of time to type out some of my
> with pop-pop boats.
> There was a series of articles in the British
> Model Boats about 10 years ago where the author was
> experimenting with pop-pops using a single coiled
> instead of the traditional pop-pop membrane-topped
> "boiler". He was using butane micro-torches to fire
> them. His experiments included varying numbers of
> coils, different diameters of tube, different
> placement of the torches, etc. to see what gave the
> best results. In one of the articles, he found that
> square-section tube worked better than normal round
> tube. He only needed a single loop of square tube
> match the performance of one of his earlier boats
> had several loops of round tube. Some good reading
> there, I just wish I could remember the author's
> or the dates those articles ran.
> Anyway, after reading about the square tube, and
> realizing I had some 1/8" square brass tube lying
> around, I decided to try it for myself. The loop is
> not even a complete 360-degree loop, basically it's
> 270-degree bend followed by a 90-degree bend in the
> other direction so that both ends of the tube end up
> parallel and pointing in the same direction. (Hint:
> annealing the tube makes bending the coil much
> easier.) Since it was just an experiment, I didn't
> feel like going through the trouble of building a
> proper hull for it, so I quickly formed a rough hull
> out of aluminum foil, poked the ends of the tube out
> through the stern, and dripped some candle wax
> the hole in the hull to seal it up. I already had
> of the little tinplate pop-pop boats that I had
> a few months earlier, so I borrowed the candle
> from that boat to provide the flame. I gave the
> experimental foil boat a test run in the bathtub.
> was faster and much quieter than the tinplate boat
> (which has the traditional pop-pop boiler). Since
> experiment was a success I removed the engine from
> foil hull and built a new 6-inch wooden hull for it
> instead. A piece of sheet brass protects the inside
> bottom of the hull from the heat source.
> Around the same time, I also bought a very small
> single-cylinder oscillating steam engine and boiler
> kit. The boiler measures about 1" in diameter by 2"
> long, and although it's a working engine, the unit
> really intended more for show than anything else.
> engine was supposed to be mounted on top of the
> and just sit there and spin and make everyone say
> actually runs on steam? Wow! It's so small!"
> that's all very well and good, but I thought it
> be a lot more fun to use it in a boat, so I built a
> base for it with the engine mounted vertically aft
> the boiler. I designed a 12.5" steam launch hull
> it, and then the idea hit me to build two identical
> hulls, one using the steam engine and the other as a
> pop-pop. I had already chosen the name "Firefly"
> the steamer, so the pop-pop version naturally became
> "Popfly", although I never actually got her
> Since my earlier experimental boat was going to be
> testbed for ideas I was going to use on Popfly (and
> since she's only half the size), I named her
> One of the things that I wanted to do on Popfly was
> build an enclosure for the fire, with a smokestack
> top, designed to look like a vertical steam launch
> boiler. When I tried it on Popflea, the "boiler"
> quickly became too hot and melted the solder joints
> holding it together. That was really the main thing
> that caused me to put Popfly on hold. Higher
> temperature solder, or better yet mechanical
> fastenings seem like the way to go, just haven't got
> around to trying it out yet.
> I have also experimented with a few different flame
> sources on Popflea, including candles, little chunks
> of esbit, and small blobs of sterno. She will run
> happily on any of those, although esbit leaves sooty
> deposits on the tube coil that can build up and
> the efficiency of the heat transfer (does burn
> than sterno though). Then, one day a few years back
> when I was staying at my sister's place, her
> told me something that she thought was just a
> bit of trivia: that brazil nuts contain so much oil
> that they will burn like a candle. A little
> immediately went on over my head, I brought out
> Popflea, cracked a brazil nut and cut it in half,
> it up and put it in the boat. Sure enough, she
> steamed merrily around the kitchen sink on nut
> Didn't smell too good, but it worked! Actually my
> sister's roommate was so impressed that she wanted
> own nut-fired boat, so I made her one with a copy of
> Popflea's square-tube engine, using a sardine can
> the hull.
> I've been giving some thought to the idea of an R/C
> pop-pop since it came up on the list here. I wonder
> if a Kitchen rudder would work on a pop-pop boat.
> those that don't know, a Kitchen rudder (named for
> inventor Jack Kitchen) is a device that is designed
> control the speed and direction of a boat with a
> single-speed, non-reversible engine. Basically it
> two curved blades that encircle the propeller, sort
> resembling a Kort nozzle when they're in the open
> position. In the closed position, the two blades
> together to form a cone behind the propeller,
> deflecting the propwash forward around the propeller
> to reverse the boat. Speed can be controlled by
> closing the blades only part-way. The blades can
> be turned together in either directon for steering.
> I'm thinking if the tubes of a pop-pop unit are
> enough together where they exit the hull, perhaps a
> single Kitchen rudder surrounding the ends of both
> tubes might work. On the other hand, the dynamics
> might be a little bit different without the spinning
> propeller in there. Guess there's only one way to
> find out! Anyway, here's a little more info and
> Richard Jenkins
> --- Craig Harder <craigmharder@...> wrote:
> > Has anyone on here actually made one, if so how
> > it work? What
> > materials did you use, and any suggestions on
> > procedures would help. I
> > have a granddaughter I would like to make one for
> > she's 8 going on 20
> > but I think she would get a kick out of seeing
> > going around her
> > pool.
> > Craig
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- i havethere was a web page that had step by step on how to biuld oneif i can find it i will post it if not i will do it step by step for you
Craig Harder <craigmharder@...> wrote:Has anyone on here actually made one, if so how did it work? What
materials did you use, and any suggestions on procedures would help. I
have a granddaughter I would like to make one for she's 8 going on 20
but I think she would get a kick out of seeing this going around her
On 7/7/06, Frank McNeill <frankmcneilll@ yahoo.com> wrote:
> Hi all,
> We have just one rule, so there aren't any other rules
> or off-topic subjects for discussion. We have members
> with different interests because invitations to join
> were sent to several groups that do have special
> topics like the design and construction of R/C models;
> construction and operation of steam powered launches;
> naval war games that use small waterline models as
> markers; maritime history; wood working; casting
> metals, plastics and Portland cement mortar; growing
> bamboo and making bamboo products, flyrods for
> example, and perhaps eventually hulls, decks and the
> like made of bamboo.
> Suggestions, anyone, for a discussion topic- it might
> even be related to development of pop-pop boats that
> resemble real steam powered boats or ships and could
> be equipped for radio or infrared control. I have a
> question, or topic, for members who design or build
> remotely controllable models, ships, cars, planes or
> whatever- are there any systems that could be used to
> actuate small valves? There are sources for miniature
> solenoid actuated valves that could be powered by four
> 2A size batteries. but I haven't been able to find out
> if there are radio or infrared receivers that can
> control valves without using servos of the kind used
> in remotely controllable models and toys.
> ____________ _________ _________ _________ _________ __
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