Model Engine News: February 2013
New Books and Magazines This Month
Engine Of The Month: FROG 500
Tech Tip of the Month
Unless otherwise expressed, all original text, drawings, and photographs created by
Ronald A Chernich appearing on the Model Engine News web site are licensed under a
Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.
First, a warning. There is a non-zero probability that the March 2013 issue of MEN will be a few days late. Ruthie and I are off on a cruise around New Zealand which leaves Brisbane on February 18 and arrives back on March 4. The tour company assures me that the ship has WiFi, so I *should* be able to release the new issue on time, but who knows? I sure won't until I try it. In the past, MEN has successfully been released from all Capital cities of eastern Australia, Portland (OR), Budapest, and Hanoi, so a boat in the Coral Sea should be a doddle. We'll see, so to speak, and if it's not there on time, at least you now know why.
On a less happy note, my back is just killing me. Even walking is painful. We don't yet know if this is related to my inoperable prostate cancer condition, or two weeks in the programmers' chair, building a data mining service for the UQ History department. If the latter, it can probably be fixed, so we are keeping fingers and toes crossed. In the meantime, even sitting in the comfy chair for significant periods has painful consequences, so pardon if our content looks a bit low this month.
Last month we mentioned some of the things lined up from Adrian for the year to come. More goodies are in the pipeline from Alex Whittaker, including full plans and build notes plus photos for his Firefly R/C glow engine. We also have sketches of a 0.5cc diesel awaiting the CAD treatment. I'd hoped to have those ready as the March Free Plan, but what with pain management, ocean cruises, University contracts to fulfill, and the general lethargy that comes with age, looks like I'll be choosing something from the "back catalogue". Now, on with the show...
LSARA is an acronym for the Low Speed Aerodynamic Research Association. Adrian came across a reference to this group while researching the Allbon model engine range and, curiosity aroused, started digging. Turns out the LSARA used models to investigate aerodynamic properties at low Reynolds Numbers. What he found we deemed worthy of an article in itself, and you can read all about it on the new LSARA Page, which we've indexed under our People-Companies list.
Speaking of which, if there is some company, or person you think we should feature, drop us an email. The "window" is closing on many and information can be hard to find, so conversely, if you have special knowledge of some pioneering engine, company, or person which you think should be preserved, send us an email too. The final editorial decision rests here, but we aim to please.
Kerosene and her friends, Again!
Back in out August 2007 issue, we tried to clarify the issue of "paraffin" and "kerosene", discovering the contributions of James Young in the process. Both names are encountered when the recipe for model "diesel" fuel is encountered, hence our previous article(s). An email from a UK reader reported difficulty buying kerosene and asked if automotive diesel fuel could be substituted. The answer is "yes", that will work fine. Kerosene (of the home heating variety) is generally used only because it is the least expensive of all the alternates. You could also use Jet-A, or Naphtha ("white gas"). Some UK garden stores sell a product for greenhouse heating called, wait for it, "Parasene". One must assume from the name that this is a mixture of paraffin and kerosene—which would be sort of like mixing water with H2O, really. That should work too, but we need some brave soul in the UK to test it before for us.
Where's My Replicator?
A book title that struck an instant chord with me was Where's My Jetpack. We mentioned this briefly back in the May, 2011 Issue and the illustration there reflects my never ending romance with all the Buck Roger's stuff (the cartoon, not that abominable TV series). One item I remember from childhood was a gadget that duplicated things. This has been a Standard of science fiction since the 1920's, and as we reported in the September, 2011 issue, ceased to be entirely science fiction several years ago. In case you were too engrossed to follow that last link, I'm talking about the RepRap and 3D printing—the real-world version of Star Trek's "Replicator"; a machine that builds whatever you want, on the spot, from a stored template.
3D printing is advancing at a staggering rate. The RepRap of a year ago, which I did not build, is now way out-classed by a host of hobbyist-level devices. Some of these are kits, but many of them are ready to run. The majority use Lego-like ABS, or biodegradable PLA plastic, squirted out of a heated extruder head. The advances in the past six months have been in the thickness of the layers deposited. The latest offerings from companies like Makerbot, 3D Systems, Formlabs etc deposit a 100 micron layer. In comparison, RepRap layers are 0.012" thick; that's 1,067 microns! There's even a sub $3,000 system which produces a 10 micron layer using the Laser from a Blu-Ray player to harden extruded epoxy. Other companies are producing an extrudable material which is flexible and conducts electricity, making it possible to include control buttons and connections to them into your design. Connect these to a microprocessor and you've stepped way beyond figurines. But it all comes back to good old RepRap and the same open-source slicing of a standard 3D model description language into 2D paths which the move X-Y servos, just like CNC G-codes. Standards and Open Source. I love it. Thank all the Ghods that Microsoft has kept their paws out of this one, so far.
Most systems follow the RepRap design in moving the print head (think glue-gun) in the X-Y plane, while lowering the table on which the part is being printed along the Z-axis, effectively building your design from the bottom-up. A recent entry in the 100 micron category comes from—or will come from, seeing as they are being "kick-started"—a company called DeltaMaker. This uses a fixed base and a head connected to three arms which raise as the print is built. The arms move in conjunction with each other to produce the X-Y motion, just like the really big, expensive CNC machining centers. This approach offers a larger print envelope than the competitors.
The rate of progress in 3D printing is staggering. Businesses are emerging who will "print" your design from a model emailed to them; true Rapid Prototyping. Below I've listed most of the current players in the consumer-level 3D printing game. I'll leave looking up the links to you; my head is spinning at the number I managed to find without trying hard.
In the commercial-level world, there are printers with very large print volumes which print in all sorts of materials. Experiments are underway printing things out of wood, and biological tissues. Printing something that lives, or can be consumed by something that lives is a way off, but I'm no longer taking bets on how far. This stuff grabs me because of the obvious model engineering connection (just look at these things), the speed of development, and the astonishing potential. There's no longer any doubt in my neck of the woods that eBooks are killing the bookstores, or at least those who can't adapt. What will the 3D printer kill, or even more to the point, what will it spawn, or replace? Honest, the Buck Rogers future is so interesting and so close, I wouldn't be dead for quids. Still waiting for my Jetpack, though that may be getting closer too...
We have two new Watzits for you to puzzle over this month. The first is a hand-made sparkie and we know exactly what it is because Jack Humpheries, who provided both, was able to provide chapter and verse, plus words and music (to borrow a saying from LBSC) for it. The other is a modern 10cc R/C glow which neither Jack, nor The Boys have a clue about. We think it has a certain Russian look to it, so we'd truly appreciate anyone who can identify it for us. All we have is provided, and while it's not that interesting in and of itself, the fact that we don't know what it is makes it of interest!
The creativeness of some model engineers continues to astound and delight. Some start with a simple, single cylinder, piston ported design like the ML Midge, or the BollAero. Others jump right in on multi cylinder four-strokes, like the Hodgson radials. Then there are the ones who start with multi-cylinder designs of their own. Dean Clark (New Zealand) is one of these and we are pleased this month to add his four cylinder boxer two-strokes to the Gallery.
New Books and Magazines This Month
Some years back, an old colleague of mine, Prof Kerry Raymond, put together a very entertaining presentation which she titled On The Interconnectedness Of Everything. This talk, which was light-hearted and somewhat tongue in cheek, was given a number of times on social occasions, and proved conclusively to any sufficiently lubricated audience, that there were no coincidences and absolutely everything connected to absolutely everything else. I mention this because this month's book review gives me a similar feeling, be it restricted to our subject matter on this website.
Our subject is Hawker: Aviator, Designer, Test Pilot, by LK Blackmore, Orion Books, New York, 1991, ISBN 0517577771 (feeling any connections yet?) As you might expect, this is a biography of Harry George Hawker (1889-1921), an Australian who made extensive contributions to early aviation. I was led to this book indirectly by his mention in a previous book review subject, namely Pure Luck: The Authorized Biography of Sir Thomas Sopwith, by Alan Bramson. I knew Hawker was a fellow Australian, and knew somewhat of his achievements, but the description of Hawker in Bramson's book as an Aircraft designer (the Sopwith Camel, no less) made me want to know more, so a search for the out-of-print Blackmore book was made. As usual, the Advanced Book Exchange quickly found me a like-new copy at less cost than the postage.
The book came about through a family connection: the author's wife was raised in the houshold of Harry Hawker's elder sister, Maude Chamberlain. There she was surrounded by memorabilia, photographs, and newspaper clippings of Harry and his exploits. Harry was also a frequent topic of conversation while she was growing up and although many of the clippings were lost following Maude's death, Lew Blackmore was given full access to the remainder, which led eventually to this biography. The book is hard-bound, 232 pages with numerous photos and black and white illustrations, including images of newspaper articles, and the full accident report of Hawker's last flight—a document unaccountably declared "Secret and Stamped. Not to be released for 50 years".
Now the connections. Harry was born on January 22, 1889 in a little village of Moorabbin, Victoria, Australia. Moorabbin is now a suberb of Melbourne and the location of one of Australia's premier General Aviation aerodromes. Harry's father, George, owned and ran a blacksmith's and wheelwright's shop in South Brighton where the young Harry developed an early interest in engineering and gained some practical knowledge. Requiring power for his shop, George purchased a treadle lathe on which he built a twin cylinder, slide-valve, double acting steam engine with water pump and flyball governor, to his own design. In 1900, George built a steam car, again to his own design. Although not a great success, it seems he had a strong influence on his son, who was taken by him visiting other engineering shops and light industry.
Harry left school at the minimum age, obtaining work in successive positions which offered him opportunities to further his knowledge and interest in motor cars. Being the chauffer and mechanic to a grazier for whom he looked after an Argyle and a Rolls-Royce Silver Ghost tourer took little effort, so with time on his hands, Harry, like his father, obtained a treadle powered lathe on which he built the internal combustion engines for two motorcycles of his own design. Our author describes them in detail and the designs and components will be immediately familiar to any Model Engineer.
In 1910, Harry and some of his motorcycle racing friends journeyed to Diggers Rest in Victoria to witness the first controlled flight of a powered aircraft in Australia. Two machines and pilots vied for this distinction, waiting days for "suitable conditions". These were as much showmen as they were aviators, with delays and theatrics designed to build anticipation in the crowd. Colin De Fries was first, but stalled and crashed on takeoff, being airborne for only a few seconds. He was followed by Erlich Weiss (aka Harry Houdini) who made a successful hop and persuaded De Fries to sign a document saying that he, Houdini, had made the first flight. All this fired Harry Hawker and his three friends with a passion to fly, so in May 1911, they departed Australia for England where all would ultimately find careers in aviation.
As we know from the Sopwith biography, Hawker found employment with Sopwiths at Brookfield, where he gained Aviator Certificate number 297. Sopwith considered him a natural and he was placed, at the tender age of 20 years, in charge of Sopwith's hangers and the competition, demonstration, and test-flying activities. The book describes these early years and the activities at Brooklands in some detail, complete with very good photographs, including Hawker flying the Sopwith Grasshopper under the footbridge spanning the famous banked motor racing track.
Bramson's biography of TOM Sopwith describes how Hawker was highly instrumental in gaining recognition for the Sopwith company, entering competitions, setting and breaking records, all the time demonstrating and promoting the company's designs. I had hoped for more detail about how Sopwith, Sigrist, and Hawker designed the famous aircraft, but in this regard, little is given beyond that in the Sopwith biography. However both agree that Hawker was highly active during World War I (1914-18), designing, test-flying, and spending time with front-line aviators to understand their needs and problems. Hawker is credited with much of the design of the Sopwith Camel, the first Sopwith aircraft to be "stress" designed, rather than eye-balled. This enabled weight savings which contributed to the aircraft's lively performance, while maintaining the necessary structural soundness.
After the war, Sopwith decided to compete in the £10,000 prize offered by the London Daily Mail for the first successful, nonstop crossing of the Atlantic Ocean. Naturally, Hawker was chosen as the pilot, but their attempt was not successful, with the aircraft, the Atlantic, having to ditch half-way in bad weather with engine trouble. The Bramson book says this failure was due to the reverse connection of the engine radiator shutter mechanism. Blackmore describes the attempt in his prologue, quoting Harry Hawker verbatim, from Hawker's book, Our Atlantic Attempt. Hawker attributes the initial cooling problems to contamination in the radiator piping causing a blockage in the filter. The two descriptions could hardly be more different.
Hawker and his navigator, Lt Cdr Mackenzie Grieve miraculously located a passing ship and ditched close by. They were picked up but were unable to salvage their aircraft due to conditions. The Atlantic however did not sink and was ultimately recovered by another passing ship. Detailed examination of the Rolls-Royce engine was made, but no foreign matter could be found in the cooling system. Blackmore conjectures that their initial overheating problem was caused by ice buildup on the radiator—understandable as they were flying in cloud and rain at 12,000 feet. Diving the aircraft seemed to help once, but the second time this was tried, the engine initially failed to respond. Blackmore believes this was due to carburetor throat icing—a phenomena unknown at the time (May, 1919), but certainly drilled relentlessly into fledgling aviators in the 1960's when I gained my wings.
Regardless, Hawker and Grieve returned to heroes' welcomes in England, receiving a generous £5,000 from the Daily Mail for their effort (half for half, seems fair). A Reception by the King of England, numerous awards, and speaking engagements made Harry Hawker a household name in England, recognized wherever he went.
So we have the first major diversion between the Bramson and Blackmore books. The second occurs around the formation of the Hawker Engineering Company on November 5, 1920. Blackmore attributes the venture to Hawker; Bramson to Sopwith, who having had to place Sopwith Aviation into voluntary liquidation, decided to capitalize on Hawker's fame when choosing the name for the new venture.
A third major difference occurs regarding the circumstances of Hawker's death, test-flying the Neiuport Goshawk (G-EASK) at Hendon on July 12, 1921. Bramson's book was published in 1990, 49 years after the death of Harry Hawker, so we might assume that he did not have access to the mysteriously restricted accident report mentioned earlier. However, the copyright page of my Orion imprint says Blackmore's book was originally published by David Bateman Ltd (New Zealand), in 1990. Perhaps his family connection gave him access to the accident report as a full facsimile is included in the 1991 book and presumably, existed in the first edition as well.
As stated in both books, although still young, Hawker was not an entirely well man. For many years, the Neiuport crash was attributed to his suffering a chronic failure resulting in loss of control, a supposition supported by the Coroner's findings. The accident report finds that the initial problem was a loose cover on the bottom of three carburetors which were located at the front of the engine, and the exhaust. This caused a fire along the underside of the aircraft (reported by some ground observers) which burnt through into the cockpit, burning through Hawker's shoes. These were found, charred with the exception of the portion of the instep protected by the rudder bar, some 90 yards from the body, indicating the burns to his feet were sustained in the air, not the fire which followed the crash. The report concludes:
...the pilot succeeded in subduing or putting out the flames but was unable to properly control the aeroplane when landing owing to physical disability caused by the burns and spinal hemorrhage.
Which account(s) to credit? You'd have to go with Blackmore for Harry's final flight, likewise his telling of the failed Atlantic crossing. I tend to accept Bramson's account regarding the formation of Hawker Engineering (later Hawker Siddeley Aviation) based on the fact that he had direct access and input from Sir Tom Sopwith, who by all accounts, was a highly ethical man more than ready to give credit precisely where it was due. Another small niggle in the Blackmore account appears on page 115 where he mentions "obturator" rings in Gnome, Clerget, and Le Rhone rotary engines. All of my other texts, including the Clerget Patent Aero Engines Instructions and Lists of Parts, call these "obdurator" rings.
Niggles and inconsistencies aside, this is a most enjoyable book for anyone interested in the early days of aviation in England. Just look at the photo here showing Sopwith Snipes and Hawker Harrier VSTOLS being made in precisely the same building! Perhaps after all this time, my wish for more detail of the early design process was too much to ask for. I'm certainly glad to having been given alternate, creditable accounts of the failed Atlantic crossing, and Hawker's final flight. The treadle lathes and engine building exploits of Harry Hawker and his father were an unexpected piece of information, making me feel a certain connection that I did not have before. Now, have you spotted the other connection? The author is LK (Lew) Blackmore, an engineer in the Royal Australian Air Force during World War II, who learned to fly in order to visit and manage the family's extensive grazing properties in eastern Australia. We've met him here before; see our August 2003 Book Review. So, a good read, easily obtainable even though out of print, from Amazon and others; four and a half stars .
Engine Of The Month: FROG 500
And now, The One you've all been waiting for (drum roll please, Mystro), The FROG 500! While the majority of our US based readers are saying "wa?", readers in Britain and the old Commonwealth countries will be transported to fond memories of this easy starting, reasonably powerful, well behaved old thing with that delightful, characteristic, un-muffled cackle—a sound heard on many control line flying fields in the 1950's and 60's—and their regret in selling theirs for ten bob to some kid in the park. As usual, Adrian has dug deeply into the engine and its variations and has uncovered facts which we believe have never been aired before. So settle back for a long, entertaining read.
Tech Tip of the Month
The ominous question, "It's 10 PM. Do you know where your children are?" was broadcast as a public service reminder to US parents on WNEW-TV (New York) during the late 1960's. The intent was serious and well-intentioned, but the announcement was parodied by a multitude of stand-up comedians, novelty song artists, and movie posters to the extent that it reached many, many other English speaking countries, Downunder (aka The Wide Brown Land, Oz, and Australia) included. And Yes, Virginia, this does have some connection with model engines.
My question might be, "Your compression screw was at 10 o'clock. Do you know where is it now?" The wandering compression screw has been the bane of many operators of our beloved, smelly, oily, diesels—or compression ignition engines to be pedantic. Our new Tech Tip is an addition to the growing How To... series. Namely, How To Stop Your Comp Screw From Wandering. Like a good parent, we'll also examine the reason why compression screws wander. Basically, it boils down to the sad fact that some are not happy at home, and under stress, decide to leave...
Another BollAero 1.8
John Cray sent in a photo of his recently completed BollAero 1.8cc diesel, which we've added to the BollAero Gallery. I like John's way with words. He says the engine runs almost beautifully and that the items on the right of his photograph represent his learning curve. John's next project will be the 1cc Weaver-Ransom which he plans to fit into his scaled-down version of the 1947 Eros plane. Be sure to have a close look at his prop-nut. Sure hate have a finger slip off the prop onto that!
This section is intended to alert you to little things that are hard to expand to a full news item, or cunningly wind into the Editorial, but are worthy of note never the less.
- Oops! The Engine Finder link to the Thermite diesel didn't work, and got called "Thermic" into the bad bargain. Fixed now.
- The Great Editorial Page Upgrade continues. This month it has been extended back to the January, 2005 issue, meaning we have just two years to go, so next month should see the end of it. Like ripples in a pond, the effects radiate out, touching other pages, so this month a record of almost 170 pages have had to be altered. Mostly, this is just fixing links broken by the changes in the Editorial pages, so don't panic; I'm doing enough of that for both of us!
- The Upgrade mentioned above has partially broken our Find facility. It still locates pages containing your search term, but in some cases, will not zero in on the actual location of the target, taking you to the top of the page instead. I know what causes this and feel sure I can fix it, but first I'll have to understand a complex piece of code written more years ago that I care to think about. Might be a boat cruise job (don't tell Ruhtie ).