Amazing as it seems, the end of 2007 is nearly on us, and as usual, I have no idea where it went. This year has marked the 10 year anniversary of the first CAD plan set I produced for our Motor Boys group (the M&M 29 ignition engine), and 2008 will be the tenth anniversary of this web site itself. Suppose I better plan some sort of celebration for that event—probably a special, extra Members' free plan (Click here for Member information). Ok, enough of all this self-promotion. Let's see what has changed in the past month.
Things are looking up, downunder. Rainfall is "normal" for the time of year in my area, although water levels are so low, this merely allows us to stand still, as it were; for the most part, the continent continues to be in a long-term and serious drought. And the Federal Government changed in the November election. For the True Believers, this is either a blessing, or marks the end of life as we know it. But The People have had their say and they have spoken so decisively that not only was the old Government (think Republican) voted out, their leader, our Prime Minister for the past 11 odd years, lost his seat to an ex ABC journalist (think PBS), who is female to boot! Regardless, the truly great thing is that the change will, as always, be accepted with good grace. No armed mobs will take to the streets and the ousted leader will initiate no uprisings. I put this down to two things. First, our two major political movements are so much alike, it's just as well they come pre color-coded, or we'd be hard pressed to tell the difference. But then, the ways in which our economic prosperity can be maintained are so limited that any government must choose from a rather limited set of options, regardless of what their public rhetoric says. Still, a bit of a change after 11 years of the same mob is good. Oh, and the second thing preventing civil disturbance? It's just too bloody hot, mate!
November has been another productive month in the shop and at the keyboard. It's also been another big month for the web site and sales of the DVD that keep the site alive. For the third month in a row, traffic has pushed the volume of pages accessed up against my current bandwidth limit (20 GB). And to conserve the last of the month's allocation, I've delayed release of the new pages until the first of the month in the American time zones, rather than the day before which is the first of the month in my timezone. I'll order a bandwidth boost next month so we can return to normal in the new year.
Lately, I've been sensing a relaxation in the rabid political correctness that has become so pervasive. It may even be acceptable for me to use the MC salutation without having to look over my shoulder to see who might be offend by it first, so here goes. Merry Christmas, One and All! See you again in 2008, and be sure to check out the revisions page for updates to pages not mentioned explicitly.
December Free Plan
Last month this arty silhouette was shown as a teaser for the traditional December Free Plan. This month, if you click on the graphic, you'll see the photo it was made from—and expose a small piece of fraudulent data, or artistic license, depending on your point of view. Brian Cox emailed us as soon as he saw it, identifying it as the rather rare "downdraft" version of the more common "updraft" Micron 5cc fixed compression diesel. Oops! The free plan is, in fact the latter, not the former. Confused? So am I, evidently. Anyway, CADing the engine was a fun project. The plans were redrawn from original factory plans provided by Brian, supplemented with measurements for the missing fuel tank kindly taken by Bert Streigler from his own engine which is pictured on the Micron 5cc Fixed Compression Diesel page. Members can log in to the Download Page for their copy of the plan. Click Here for more information on becoming a Member.
This just about rounds out the model engine types provided as free plans: compressed air (steam even), spark ignition, glow plug, variable and fixed compression "diesel". Unless I have a spark of genius, from here on, it'll have to be variations on a theme for the next ones—and before you ask: yes, a gas turbine is completely out of the question. Of course, there's always the dreaded pulse jet to consider. Hmmmm...
Web site stats show that the ETW Whippet Project was the most popular page (after the monthly Editorial page) last month. The engines are progressing nicely and this month, Page Two of the construction series details making the camshaft and associated drive components. Lest you all believe that I'm some kind of machining wizard with super-human productivity, I'll confess to taking a week of annual leave in November, which was spent Whippeting wildly (actually, my University said use it or lose it, so the decision was a bit of a no-brainer). In fact, actual progress has extended well past the written-up progress, as might be guessed from the engine in the background of this shot. And while all has not been plain sailing, I'm still prepared to categorize this engine as being easily within the capabilities of a model engineer with intermediate, or even advanced-beginner level skills. Next month, we'll cover the reciprocating bits.
Since last month, two more errors in the original Whippet plans has been found which are not corrected on the Woking/Hemingway plan reprint. And even though I knew about it, I managed to make two very nice, yet completely useless conrods to the originally published and very, very wrong between centers dimension (I don't want to talk about it). As penance, I've updated the Whippet Introduction page with details of all these corrections.
Father of the Gas Turbine
Don't know about you, bit I love learning new things, and the more obscure the better! In the last few months, we've had a bit of a gas turbine theme, reviewing books on model gas turbines and Sir Frank Whittle, who has been named the father of the jet engine. One of our strong supporters from Norway emailed asking if I was aware of Jens Elling. The answer was no, which highlighted more of my ignorance because I certainly should have been since he is correctly credited as being the father of the gas turbine. To quote a translation of the web page dedicated to him:
Jens William Ęgidius Elling (also Aegidus or Aegidius) (born July 26, 1861 - died 1949) was a Norwegian inventor who is considered to be the father of the gas turbine. His first gas turbine patent was granted in 1884. In 1903 he completed the first turbine that produced excess power; his original machine used both rotary compressors and turbines to produce 11 hp net at 17.000 rpm. He further developed the concept, and by 1912 he had developed a gas turbine system with separate turbine unit and compressor in series, a combination that is now common. Elling's gas turbine prototypes from 1903 and 1912 are exhibited at the Norsk Teknisk Museum in Oslo.
The advances made in material science in the past 100 years are much overlooked. Elling's achievement was made before World War I when the metals of the time were barely up to the production of the rotary engine, just as materials in World War II were barely up to Whittle's turbo jet engine. Then there is the influence of fuel chemistry to consider—well detailed in Graham White's book, Allied Aircraft Piston Engines of World War II, which leads us, in my usual 'round about way, to the next item...
One of my most favorite movies of all time is Brian dePalma's Phantom of the Paradise, a rock musical scored by Paul Williams, and starring Paul Williams (he also wrote most of the Carpenters hits, and the Love Boat theme, but we forgive him). In one scene, a Beach Boys like group belts out a surfin' song that starts with a spoken line: "Carburetors, Man. That's what life is all about!" Well did you ever wonder where the word carburetor (or carburettor) came from? We rather take the term for granted, even in these days of fuel injection, but somebody in relatively recent times must have invented it. Obviously the name was a good one as it has quietly passed into every day usage. The Williams' lyric quoted above may be a spoof, but no self-respecting male adolescent of the 60's did not profess knowledge of the things. Now, while leafing through an old copy of the Model Engineer last month, I came across a two part article by Edgar T Westbury that I'd not seen before, appropriately titled, Carburettors Ancient and Modern, wherein the mystery is touched on. To quote his text:
The first designers of liquid-fuel engines found that the simplest way to supply fuel to the engines was to "carburate" the air by bringing it into contact with a volatile hydrocarbon spirit on its way to the engine cylinder.
Obvious, when you think about it. A visit to the much maligned Wikipedia supports this, adding that:
The word carburetor comes from the French carbure, meaning 'carbide'. To carburete means to combine with carbon. In fuel chemistry, the term has the more specific meaning of increasing the carbon (and therefore energy) content of a fuel by mixing it with a volatile hydrocarbon.
The entry also notes that in North America, the word is spelt with a single "t", while the international spelling uses the double letter.
Of course, times change; cars use fuel injection and kids no longer fiddle with them. I haven't even seen the engine of the thing I've been driving for the past four years—it would have to go on a hoist for that! Appropriately, the only place outside of vintage auto clubs you are likely to hear the term today is in association with model engines. So now you know, and can put that know-it-all at the flying field in his place, asking if he even knows what the word means, let alone how to adjust it!
Look! Up in the sky...
Bruce Satra (Vernal Engineering) has had this one on the boil for quite a while, but it's all systems go now: the Morton cylinder based, horizontally opposed two cylinder four-stroke castings and finished parts are ready to ship. See the new SM-2 price list page for details. The "S" part of the designation is for Super, not Satra, although there is not much difference between the two words when it comes to the quality of Bruce's investment castings. The SM-2 and SM-1 now have modified cams for better performance. Work is well advanced on a new cylinder too that will incorporate larger valves and a repositioning of the pipes to simplify Glen Morton's infamous Prize Pretzel, otherwise known as the M5 induction tubes.
Speaking of the M-5, a cut-away model of which is pictured here, Bruce has issued a revised price M-5 list and now offers ready made parts that builders could make, but may choose not to; things like the crankshaft, and those pesky inlet pipes, for example. There are only three bends in the pipe, but none of them are in the same plane, and all must be made at precise angles and distances apart if you are to have any hope of assembling the thing. This, and other lessons from builders has led to the SM-5, which is quite a different beast from the M-5. This design will be announced shortly and should be the one to build if you want to fly. However, parts compatible with the old Mortons will remain available.
Then there is the SM-7 and SM-9, being seven and nine cylinder variations on the theme. These embody all the lessons taught by the M-5. Things like the extra support bearing for the cam gearing train, roller tappets, higher compression for glow plug ignition, 4140 steel rockers, and a re-designed and balanced crankshaft design by Bob Roach. For those who don't know, Bob is the Ozzie designer of the outstanding Pratt & Whitney R-1830 and Wasp Junior scale radials—the latter pictured here, being built from Vernal castings. The cams for the SM series radials have been redesigned too. The Morton design used a single cam ring with cunning spacing and angling of the tappets to lift both inlet and exhaust valves from the same lobes. This is compact, but forces a compromise on valve timing and profiles. The new designs have separate cam rings for inlet and exhaust, a more conventional design that further enhances performance: these engines are designed to fly.
Eagle-eyed inspectors of URL links will have noticed that the Vernal Engineering web site is a sub-domain off Model Engine News (that's Bruce's slave at the mill here). So is Roger Schroeder's Classic Engines. But there is no financial connection. I count both these fine gentlemen as friends met over the Internet through our shared love of model engine building. Web sites and the associated technology are as easy for me as casting is for them, so I host and maintain their pages as their privileged friend. You can judge if this makes me less than impartial to their work. The hard part is stopping them both sending all sorts of wonderful, gratuitous graft that I love so much! But honestly, I have no reservations recommending the stuff they both provide, and none of us are going to be buying condos in Vermont on the proceeds.
Seems that I get at least one email per month asking where plans for the NE15S SOHC bar-stock four-stroke can be bought. The answer is the man himself, Malcolm Stride (aka "Nemett"), designer of the engine, IC Topics editor for the Model Engineer, and author of Miniature Internal Combustion Engines. Although the construction series for the engine was serialized in Model Engineer, the plans for the engine are not available from them, so a belated entry has been made in the Suppliers Page under the "Plans" heading.
And since this month's Whippet piece involves harmonic cams, I better come clean and confess to an error, now corrected, in the new version of CamCalc that was announced last month. The Imperial option worked fine—and was used to produce the Whippet cams—but choosing metric as the units caused the lift figured to be multiplied by 1000, making them rather hard to machine. It was Malcolm who brought this to my attention, so thanks Malcolm!
Super Fury Repro
If a reproduction of the ED Super Fury is to be made, who better to make it than the original designer, Gordon Cornell? Gordon has been engaged in this project for some time and is now approaching the packaging stage. He would like to include a copy of the original instructions, but the only copy he has is rather tatty, so here is your chance to help. If anyone has a good condition set of Super Fury instructions, please contact me and we'll decide what will be the best way to get a copy to Gordon. And if you don't, never mind—just watch this space for more news regarding availability.
Wanted, Dead or Alive
It's been a year since the page listing my Buy and Sell: Wanted! wish-list was last updated. Strangely, each time it is, the list seems to grow rather than shrink. This time, (ahem) a few wants in the nature of old Model Engineer issues and complete volumes have been added. As the publishing cycle for the ME is fortnightly, complete volumes of this magazine are heavy. And as the buyer pays freight, I'd like to hear from people in Australia; Brisbane would be nice, across the street would be even better! But don't let that stop you. Members and other Cookie Monsters will know why these are required .
New Books and Magazines This Month
Model Engine Builder number twelve arrived last month. The feature article in this issue is a design by Phil Watt called the SeaDog. This article is of interest for several reasons. First, the engine itself is styled as a tribute to ET Westbury, a name we can't seem to escape here. Second, in attributing the style of the engine to ETW, Phil names him Edgar Thomas Westbury. Now I searched, and searched (including births, deaths and marriages) trying to uncover just what that "T" stood for, totally without success. I finally concluded that it must be like the "A" in Ronald A Chernich; I know what it stands for, but I 'ain't tellin'! If Phil has it right, this is a good piece of trivia and I'd like to know the source. The SeaDog is a 13cc, water-cooled, overhead valve, spark ignition four-stroke (it can also be built for air cooling, but it really belongs in a boat). The article provides good, clear photos of the construction and adequate building notes for the advanced beginner. I was especially tickled to read his description for ring making which simply says that the best article on making rings is the Feeny Construction Log, Page 8, with a reference to the page on this web site (thanks Phil, your check is in the mail ). Nice to be appreciated, even when it's for work that I don't consider to be my best. The engine looks nice and Phil can supply casting sets to prospective builders.
There's good stuff in the rest of the issue too, although I struggled with the RAW piece. But who am I to criticize? Editor Mike Rehmus says that from feedback received, his readers absolutely love Bob Washburn's column. So I sure won't begrudge the few pages devoted to recollections while it makes others happy. As usual, if you don't subscribe to Model Engine Builder Magazine, you should. I happily give issue 12 of MEB four and half stars .
Having mentioned it above, a few words about the Allied Piston Engines book would be appropriate. I've had this one for about ten years, but a quick check at Amazon shows that it is still in print and available: Allied Aircraft Piston Engines of World War II, by Graham White, Society of Automotive Engineers, Inc, 1995, ISBN 1-56091-655-9, hard-bound, 426 pages, profusely illustrated. The name Graham White will certainly need no introduction to regular readers of the Aircraft Engine Historical Society magazine, Torque Meter, wherein he writes a regular column, appropriately and cleverly titled, "From the White House". Graham is also an ex-aeromodeler whose favorite engine is the ETA 29, making the inclusion of his book here most appropriate.
In Allied Aircraft Piston Engines of World War II, he tries to not just describe the engines used by the Allies of World War II, but place them in context with other developments in metallurgy, fuel chemistry, aerodynamics, and a myriad of other seemingly insignificant aspects that interacted with engine design and development. While this is only "half the story" as it were, he never claims anything else. And I'm not sure I could lift, nor afford a book that included similar detail for ALL sides of that conflict! His writing appears reasonably well researched, and while not over-burdened with references, it does contain enough chapter end-note references to show his sources. However it remains completely readable by non-scholars for all that. It's good to be informed and entertained, all at the same time.
Chapter One describes all those contributing aspects hinted at above. This is followed by two sections, the first dedicated to British design, the second to the US contributions. In each, we find the usual suspects: Rolls-Royce, Bristol, Napier, Pratt & Whitney, Allison, and Wright Aeronautical. Another chapter picks up the smaller US players; names like Lycoming and Continental. From chapters dedicated to the different manufacturers, we then see the expected list of engine names: Merlin, Hercules, Wasp, Cyclone, etc, etc. For each engine, details of its construction and development are provided, along with enough illustrations to enable readers to see how it works, its strengths, and its weaknesses. The less successful engines like the Rolls-Royce Vulture and cooling problems with engines like the R-4360 are also discussed.
The chapters include some descriptions of the aircraft the engines powered, although as the main focus is the engines, the aircraft get small consideration and the lists are by no means exhaustive. You could argue—as one reviewer on Amazon does—that by not being definitive, they serve a negative purpose and should have been omitted. But their inclusion does give the author the opportunity to discuss how installations varied with aircraft mission. For example, the way you insert a Merlin into a P-51 fighter is a tad different to the way it is plumbed into a four engined Lancaster bomber! A final and very brief "Conclusions" chapter does not actually draw any real conclusions, except perhaps that many remarkable people whose like we will never see again rose to meet a host of trying challenges at a time of extreme need. I don't want to infer that people of their caliber are not around any more. Aircraft performance and problems today are more complex, requiring massive team efforts, so the contributions made by individuals are less visible. Still, it is truly amazing how far we've come in the past half-century.
I really liked this book for the context White placed around his descriptions, and the well chosen and reprinted illustrations drawn from many sources, including manufacturers' maintenance manuals. It's a book I've referred back to many times to clear up some detail about big engine technology, and will again, I'm sure. Allied Aircraft Piston Engines of World War II is still available from Amazon for just under $60 and I give it the full five stars .
Engine Of The Month: Vltavan Variations
We better start out with pronunciation on this one before anything else. The Vltava is the longest river in the Czech Republic, meandering through Prague and other cities before emptying into the river Elbe. The Wikipedia entry has a pronunciation example and hearing it spoken is probably better that me playing games with syllables and emphasis marks. Vltavan seems a popular lable for all manner of things Czech, from Hotels to Horse Breeding Studs, and at one time in the past, model engines too! As I've been busy Whippeting away in the shop, this month's engine review(s) again come from Adrian Duncan's keyboard and my blue editing pen. The results is a pair of reviews for the two mass-produced engines from Vltavan Praha, and an almost-Watzit made by some unknown but talented person who joined two Vltavan 29's together into an alternate firing, in-line twin! As Adrian describes, the engines combine good and awful aspects, so call up the Engine Finder and use the New Links section to access the reviews. If you get really turned on by these Czech creations and want to know more, check the new entry on the Links Page to Jiri Linka's book on Czech Model Engines—I've not seen a copy, but I've heard favorable third-hand reports.
Tech Tip of the Month
This tip came about as a direct result of a set-up problem I encountered while working on the ETW Whippet Project. Perhaps it should have been described there, but as it addresses a general problem, a How To page for it seemed a good idea. The Whippet series can just reference the How-to page when we reach that stage. The actual tip involves set-up of a casting where the things you need to align on are invisible just when you need them most. The answer, and a very simple one it is too, was found in another ETW construction series. So click on the thumbnail, or follow this link to the tip on mounting cast, cored, pistons for wrist pin drilling.