Happy New Year! And no, the image is not Yet Another of Ron's screw-ups. Hopefully all will become clear in a little while. I rather enjoyed 2007 and hope it was good for you, too. I'm sad to see it go though, because, well, it's another year gone, dammit, and I'm running short on them! At least I won't be faced with another one of those horrible birthdays with a zero in it for a while now that 2007 is gone. All through Christmas down here, there's been a severe low pressure in the Coral Sea that's been trying to make up it's mind if it should be a cyclone, or not. The answer seems to be no, but the result has been (joy) comfortable temperatures and (less joy) very high winds battering the coast, closing beaches and causing misery to campers. I Don't Camp, so this is no hardship to me, but it has some other side effects, like the cancellation of annual firework displays due to the high winds, and perhaps the lead graphic is now explained (hint: check last January's page ). And if you think this weather pattern was good for some much needed rain, you'd be wrong. Seems we just can't take a trick...
Thanks to all Members and Lurkers for the increasing popularity of the MEN web site during 2007. And a special thanks to all those who emailed to say how much they enjoy the site, including these bursts of verbal diarrhoea that pad out each month's meaningful content! It makes all the effort worthwhile. 2008 will be the 10 year anniversary of the web site and I'm frequently astounded at what the site contains. Sometimes I'm embarrassed too, but while I will correct things that are wrong, I resist the temptation to erase history by changing the "intent" of prior writings. Or maybe I'm just too lazy.
This month we have a good spread of stuff, including a lot of new Whippet pages. As I write this on New Year's Eve, all parts are made and ready for final assembly—the "fiddlin' and fettlin' stage", I call it. Some parts need refinement, and I really should make a complete new set of valves due to a misread thread size—and probably will, even though the existing ones will work. On other fronts, and as usual, the things I privately set myself to do during the year remain undone, even though last year's resolution was No More Resolutions! Looks like I even failed on that score too. Still, I'm not unhappy about the state of play and hope 2008 is a good year for all of you out there, everywhere. Now to business...
Yet More Whippet Progress
The Whippet project is really forging ahead. They may even be running as you read this (now there's famous last words if ever I heard them). This month, four new pages describe the working bits: crankshaft, conrod, cylinder liner, and piston. Certain, ahem, difficulties with the nose piece casting—now corrected by Hemingway kits—are also described. I'm also past the "barrier" on the project. All projects seem to have them; this is the step that fills your mind with apprehension, or terminal boredom, and can cause a project to go under the bench forever. For the Whippet, this was the drilling of the holes in the crankcase for the head attachment studs and water cooling passages, then precisely duplicating those in the head itself, and the head cover plate. The elevated apprehension level came about through having seen the proverbial pig's ear an otherwise competent model engineer had made of this step on an ETW Seagull. But with a sound plan of approach, the job was simple and the results perfect. This will all be described next month, but in the meanwhile, there are a lot of pictures and text to go on with and I'm sticking to my "advanced beginner" classification on this engine. Working with big parts definitely helps!
Yet More Whippet Plan Bugs
This one was found towards the end of the month after the new Whippet pages were put to bed. I've had emails from others who are thinking of making a Whippet and as this one is a bit serious, I made a New Year's Eve decision to add it as another news item in case I get hit by the proverbial bus before the February Issue comes out. As can be seen on this composite of two parts, there is strong disagreement to the tune of 1/16" (1.5mm) over the spacing of the head bolts between the cylinder head and matching water cover. Sadly, the head cover has bosses with deep bolt position dimples cast in that use the incorrect 15/16" dimension, plus a bit. If these are blithely used as the "master", you'll be in deep diabolicals as the bolt holes will intersect the cylinder liner. I don't like the 11/16" radius for the front pair either. This places their edge 0.002" away from the liner flange which seems a trifle close for comfort, and a decent thread. All eight water passage holes "Z" are badly positioned too. The four highlighted in yellow are the worst, so I've omitted them. If I'd thought about it more, I'd have repositioned all of them. More next month, but in the mean time, if you are building a Whippet, you need to be aware of this problem.
Yet More Whittle Bio Info
Readers may recall the praise I heaped on the Whittle Documentary that aired on Discovery Channel here last year. During December, I received a delightful email from the producer of the show, Nicholas Jones of Quanta Films, thanking me for the positive review and referring me (and you) to the production company's web site at http://www.quantafilms.com. 2007 marked the centenary of Sir Frank Whittle's birth, a occasion let slip silently past by Officialdom in Britain, thus keeping up the fine, established tradition of benign neglect he has attracted—as it were. However to mark the occasion, Quanta produced a "feature length", 71 minute expanded version of Whittle - The Jet Pioneer. This is available as a DVD (with bonus features) and as a full-screen, high resolution download. The DVD is £17.99 while the download is a mere £4.99 (and no, I don't get commission ).
Nicholas also mentioned that he had recorded interviews with both Frank Whittle and Hans von Ohain (I seem to recall from the Third Form that when two vowels appear together in a German word, the first is silent, so it's "O-hin"), but sadly not Herbert Wagner. "Who?", said I, displaying my ignorance. Google to the rescue. Try the Scientist and Friends web site for a good guide to all the players. Incidentally, I've been reading the biography of Hans Ohain. It will get the review treatment in the fullness of time.
Lower Jaw Retention Required
Paul Knapp who operates Model Engineering Museum knows a thing or two about the Bentley BR2, having made some of them. He casually sent me a link last month to a German language web site saying MEN readers might enjoy the slideshow there. It shows the builder's modest project: a Bentley BR2 rotary built in 1:1 scale! I've added the link to the non-commercial section of the links page. Pay a visit and watch the slide show. Does not matter if you don't read German, just look at the pictures and remember to close your mouth occasionally as you contemplate the effort involved—especially when you consider that it looks like he made two of them. The URL is http://www.setzstock.de/motor/.
While you are in the links page, have a look at the other new link for this month which is a projects, hints and tips page from musical instrument maker, Frank Ford. As well as some good tips to model engineers, he has a project build of the MLA Die Filing machine, castings for which are patiently aging under my bench.
Watzit Identified as Historic
There are a couple of new Watzits this month, plus we have received positive identification of Adrian Duncan's Czech Watzit. As the story emerged, the answer was deemed so staggering that concrete conformation was indicated before this information could even be hinted at. That we now have, and Adrian has placed an armed guard around the engine. His grotty little engine turns out to be one of the first "diesels" manufactured outside of Switzerland. Specifically, it was made in Prague during 1941. The story behind it, complete with assassination plots, appears on the new Půrok-Bušek 2,0 page. Thanks go to Adrian for ferreting out the data, our new friends in Czechoslovakia for the data itself, and David Owen for providing the dose of healthy skepticism until enough evidence was obtained to move us into "beyond all reasonable shadow of doubt" territory.
Speaking of doubt, recall that last month, when reviewing Phil Watt's Seadog, I mentioned that Phil expanded the "T" in ETW to Thomas? Confirmed data on just what that "T" stood for was a puzzle I'd previously attempted to solve and failed utterly, despite consulting the berths register for 1896. Well, an email from Phil has provided the proof, and the reason for his success: ETW was born December 30, 1896, so it is highly unlikely that this would have been registered until 1897, and sure 'nuf, there it is, Edgar Thomas! Mystery solved and the Biography page updated appropriately. Thanks Phil!
Exactly twelve months ago, I was busily building an EDM to fix a problem entirely of my own making (six weeks and $800 spent to redress 30 seconds of impatience—gotta be a lesson there, somewheres'). My working life started in the aviation electronics industry almost 40 years ago, so the thought of chassis bashing, wiring looms, and bread-board layouts was just a matter of revisiting old friends (was once an "Amateur", or "Ham" (no wise cracks please) VK4-ZSC, back in the days when you made your own receivers and transmitters too). But I know this is not the case for everyone, and many who might like to build a home-shop EDM to the elegant design described in Ben Flemming's book are daunted to inaction by the prospect of wiring up those mysterious caterpillars and beads. Well, help may be at hand. Ben can now supply a very professional double-sided, thru-plated, silk-screened, epoxy printed circuit board that makes the job about as simple as it's ever going to get. The board costs US$23.00 including postage in the US. Outside the USA, email Ben for shipping estimates. Even better, he takes PayPal and you can order the book from him at the same time. Be sure to mention Model Engine News so he knows the original graft in the form of the review copy of the book he sent me is still paying back .
Updated Pages and Other Things
A glance in the Updated Page Index this month will show that all the Engine Gallery pages have been changed. A reader alerted me to a couple of typos and spelling mistakes including one that a spell checker would not find. In fixing these, I found a few more, so the net result is that all of the pages have been updated, but only the "current" page has actual new items. Naturally this entry is time specific and applies only to the Updates Index during January, 2008; it will be different next month. But this link to the Tempest 90, shown exploded here, is permanent.
The DVD Cookie got an overhaul 60 days ago too, growing by almost 40%, with some presentation changes and backwards links on series. It is now almost twice the size of the one on the old CD. Any MEN Members who subscribed, or updated during Nov/Dec 2007 have the new cookie. Members will know the sort of thing it contains and can order an update at any time for $15. It will continue to get bigger over time, but I think it will be "stable" for a while.
New Books and Magazines This Month
Collectors of engines that include examples of Continental origin, together with engine designers and builders searching for design ideas will appreciate this month's book—Ĉeské Modelářské Motory (Czech Model Engines), by Jiří Linka and Jan Kafka, published in 2004. In presentation and format, the book is effectively a Czech Clanford, improved by providing three photographs of each engine, and a table that presents the vital statistics for all the entries. It contains 160 pages picturing 315 engines in alphabetical order, with an introduction in Czech and English.
This page is typical of the content and was selected because I rather like the look of both the engines, in fact, all of the eight ZOCH engines pictured in the book are quite attractive, but then, most of the ZOCHs are twins any my twin addiction is incurable. The rather home-made look is explained in the introduction. This describes how there were very few "professional" engine producers in the Czech Republic. Instead, small production runs were made by amateurs, who the authors charmingly refer to as "pattern makers". The text outlines the history of Czech model engine making, clearly acknowledging the origins as copies of the German Felgiebel and Eisfield, plus the American Brown Junior. The engines in the book have been lovingly restored by Jiří Linka and while most are identified, there are quite a lot of Czech Watzits illustrated (if Jiří can't identify them, they will probably remain unknown forever). You can order the book direct from the Czech Model Engine web site and pay with PayPal, or email Jan Kafka if you have questions. My copy arrived, well packed, in less that ten days and I'm quite pleased with it. Already I've gleaned ideas for engines I'd love to design and build, like that little ZOCH side-valve four stroke. Four stars .
How can I have ignored this great book for so long!? Not that it has not been mentioned—in fact mention goes as far back as Page 1 of the Gallery which must be circa 2001, but somehow, an actual review just never happened. An email received just before New Year's Eve from the author's son, also named John, informed me that the Gallery page linked to an out of date contact address. This was quickly fixed, but I felt more was needed, so the January issue got a last minute update. The book is Dan Calkin And His ELFs (He Never Called Then Elves!), by John J Brown, ISBN 0967366607, Model Aviation Books, Santa Clara, CA, 1999, US$49.95. This is a beautiful hard bound book of 264 pages, copiously illustrated with pictures and diagrams that will delight collectors and engine builders both; at least it sure delights me, regardless of which hat I'm wearing. The subject is the ELF engines designed and built by Dan Calkin, as if you couldn't guess.
The text starts with a description Dan Calkin's early life and of how the ELF engines came into being. In five chapters, we follow production from a Portland (OR) basement through a succession of moves and design changes, put together with information and "scrap book" photos made available to the author by Dan Calkin's widow and daughter. The next nine chapters comprise the bulk of the book. These detail all the ELF production engines with individual chapters devoted to "modules" and the variations made to them over the years. The last four chapters describe the tooling used to produce the engines, a four stroke that never reached "production" state, and a remarkable R/C project. The book concludes with a series of Appendices that explain the ELF serial numbering and reproduce the record of sales that lists ALL ELF engines made by type and serial number with the date they were sold, and to whom! And yes, there are holes in the sequence, and genuine instances of the same number being used more than once.
Now you may be wondering why a book on engines dating back to the Great Depression should appeal especially to engine builders? Have a look at this sample page. It is one of 16 that show the jigs and tooling used by Dan Calkin in the manufacture of his engines. His designs were highly modular, allowing parts to be shared across the range from one to six cylinder engines. His initial "factory" was the family basement and his techniques are similar to those used today by amateur builders. There's an idea you could use on every one of those tooling pages! For engine restorers, the appendix data will enable them authentically undo any mods an engine might have been subjected to over the years.
The ELF engines attract their fair share of controversy. Dan had some strange ideas; some good, some questionable. The aluminum piston in a steel liner of the originals did not help, especially in dusty climates (no problem in Oregon ). All were essentially hand made by Dan Calkin and his family from raw materials—Calkin even did all his own casting, so the total produced was low. The comprehensive sales register covers the period 1939 to 1956, listing about 1,760 engines. This, together with their unique appearance (love it or hate it), accounts for the remarkable prices they change hands for today. I have to give this book Five Gold Stars and a Koala Stamp. You can order it new or used through Amazon.
Engine Of The Month: Vega 30
The first Engine of the Month for 2008 is a British bar-stock four-stroke that is not the well known and respected Laser series by Niel Tidy. Externally, it has more of home-built look to it, in fact, it would make a great project for amateur engine builders wanting to tackle a simple four-stroke project and not greatly worried about performance. Click the thumbnail picture, follow this link, or look in the Engine Finder for the brief history and technical overview of John Harbone's Vega series of side-valve four-stroke model engines.
Tech Tip of the Month
Looking over past issues of this web-zine, I see that I first played with 3D modeling and rendering five years ago in the January 2003 issue. While the results were satisfying, the process—using my weapon of choice, TurboCAD—was cumbersome and the returns disproportionate to the effort, especially if some part needs to be revised. Add to that, I found that the skill needed to be reinforced by frequent repetition, else it fades and has to be re-learnt. So after the initial flurry, such pictures have disappeared from these pages (so much to do, so little time, etc).
But I keep seeing 3D CAD is use. It was used to great effect by Robert Siegler on the Morton M5 drawings and illustrations for the Model Engine Builder series, and by many subsequent plan sets in MEB drawn by editor, cook, and chief bottle-washer, Mike Rehmus, including the nice little Seadog mentioned here last month. My Alter-Ego, a creature who can at times be more vocal than Buster the Burmese cat, refuses to believe that there are others out there who are more productive than Alter's host, sonorously declaring that it Must Be The Tool, and that I should investigate a thing called Alibre Design, so I did. The picture below of the Whippet carby represents maybe two hours of effort. Even better, I can make changes to any part of it in seconds and the process is simple enough that frequent reinforcement should not be required. I'm not throwing TurboCAD in the bin, but there are some truly great and useful features in the class of programs called "parametric modelling tools" that it is worth knowing about.
Alibre's parametric modelling tool came out of the automotive design field as a low cost per seat alternative to the high-end packages that carry prices equivalent to a new luxury car. Low cost is a relative concept too. The top-end Alibre package is about $2K, but at the other end is Alibre Design Express, which is a free download. This is known as "puppy dog" selling: if the thing is cute and cuddly enough, the sucker (that's me in this case and thank Heaven for academic pricing) will plonk down the bucks after holding it for a while. The Express version places restrictions on the number of parts in an assembly, and a few other things. You can still assemble components, but it won't save them beyond a certain complexity. The Whippet Carburetor pictured here is just within this limit, so it may be quite sufficient for many users. Guess I should explain why parametric tools are different from traditional CAD.
Building a "model" is done by making a rough 2D sketch of a shape, then placing constraints on the rough sketch to make it the precise size and shape required. For example, a dimension is a simple constraint. So is setting one line parallel to another, or setting it to a length that is related by a formula to another object. The program keeps track of the "degrees of freedom" in the sketch. When this hits zero, the rough 2D sketch is no longer rough and can be projected along the third "3D" axis as an extrusion, or subtraction from a previous extrusion. It's very much like machining a part from solid. You start with a basic shape, remove a precise amount here, add a bit there, until the part is finished. Holes can be bored, drilled and tapped, just like they are in the real world. Once a part is complete and saved as a file, make the next, and the next, all as separate parts. Finally, the parts are assembled, applying 3D constraints that specify the alignment and relative position of the parts. So? 3D modeling in CAD is not all that different. Where's the big advantage?
Well for one thing, you can go back to any of the little intermediate 2D sketches, make a change (alter a parameter—hence the term "parametric modeling"), then have the system re-apply all the subsequent steps you've made. Some might have been invalidated by the change, so you can edit these (or remove them in isolation) until the part regenerated cleanly. In short, complex changes are truly EASY, and FAST.
Once you've completed an assembly, you can rotate your view of it to see how it fits together. You can make the parts translucent to see the internals too. Even better, you can move individual parts in relation to the others under the alignment constraints you've applied to them. In one of the tutorial exercises provided with the package, you assemble a V8 block, crankshaft, cylinders, pistons, rods, and caps, then turn the crankshaft and watch the pistons go up and down. Better, you can ask the tool to do this and highlight where any part tries to occupy the same 3D space as some other at the same time! In this screen shot, the red areas indicate an interference between parts that are highlighted in yellow. This shows a problem between block and piston at BDC.
Paradoxically, creating 2D plans presented a steeper learning curve than building the 3D model! On the surface, this is easy. Choose a drawing sheet template which will define the projection type (first or third angle), the part or assembly to be drawn, the orthogonal views you want included, and a scale (or let the program auto-scale it). You can include any of the isometric and "exploded" views of assemblies, or add them later. The package then generates the drawings from the model, optionally with dimensions taken from the sketch constraints, hidden detail lines, hole and thread callouts, etc. The result is a bit of a mess, dimension wise. But these can be moved, or deleted and new dimensions added (but not changed, all being "locked" to the actual model). Subsequent changes in the model carry through to the drawings. So why am I less than thrilled? In a word, personal aesthetics (opps, two words). I've developed a "house style" with line weights to produce MEB plans that provide all the required information, and look attractive, or so I tell myself. The drawings produced by Alibre are precise, but look mechanical and sterile; they have no soul. On the other hand, they are to ISO standards and can include dual dimensions. *Sigh* I should probably just get used to it and move on, taking the isometrics, the exploded views, and standardization as adequate compensation.
So can I throw away the traditional CAD package? No, not really. During the month, I needed to produce a drill jig for the head bolt and cooling passage pattern for the Whippet. No need to "model" that in more dimensions than two. Just some holes dimensioned to a common datum that could be quickly and accurately drawn, printed, and taken down to the workshop. The job could have been done in either tool, but I can't help feeling traditional CAD is the optimum choice in this case.
The big trial for Alibre has been modeling a gear cutting machine published in the Model Engineer, circa 1949, able to produce spur, bevel, and helical gears of modest size. This device is in effect, a miniature horizontal milling machine with a swiveling head. The model quickly highlighted that some dimensions were quite wrong—a bit unfortunate as Hobby Mechanics had already produced patterns and castings by the time the model advanced to the point to show that a number of bolts could just not be made to fit as designed! But I am now totally sold on the value of 3D modeling for complex projects like this. I will persevere with the 2D Plan preparation process for what we are calling the GC100. Plans will have dual metric/Imperial dimensions, and if we can find a way, the device will be self-powered rather than relying on a belt to an external motor. The exercise of creating the model was used to develop skills in the Alibre package. The picture here represents perhaps 20 hours work, a significant amount of which was spent learning the tool and viewing the excellent "training videos", some of which are available on-line from the Alibre web site. Time will tell whether this represents a true paradigm shift, or is just another of Ron's fads.