August in Brisbane is the coldest time of the year. For a week or two, the wind turns westerly, bringing cold air in from the desert-like center of the Wide Brown Land, driving the temperature down, sometimes reaching close to freezing overnight. Ok, I admit that's not all that cold as some measure it. It will still reach 22C during the day and I see hardy students walking around the campus wearing tee-shirts and bare feet in the early morning, but it still feels cold to me. So I spend my evenings rugged-up, reading and researching, not building. In consequence, no progress on anything except the annotation software the University of Queensland is building for the Atlas of Living Australia, which is progressing quite well, I'm pleased to say.
But if I've been less than productive, Les Stone has been as prolific as ever. His latest effort is the one in the center of this shot: a reproduction of the rare and sought after Atomatic 3cc diesel. This Italian engine, designed by Uberto Travagli, exhibits the stylistic appeal we typically associate with Italian design of all kinds (except possibly aeroplanes ). You can see more pictures of Les' latest on the Les Stone Tribute Page.
Last month I threatened that the August issue would be shorter than we've seen in recent times. Well, it is, but not all that much. We have reviews and information on three old engines, and a How Not To Tech Tip. Hope you enjoy it.
Large Engine Collection to be Sold by Auction
Ron Moulton, the Dean of English aeromodelling, has provided the following advance notice of a significant collection to be auctioned later this year:
Professor Doug Walton is known in Britain as a leading connoisseur of model aero engines. As an enthusiastic student of engine design and development he accumulated an enviable International collection of examples. They ranged from series production sport engines to highly specialized individually prepared performance powerhouses. Many rare types were acquired. Historic trendsetters and novel experimental innovators are intermixed with familiarly known brands from all over the world. Kept as a record of model aero engines from earliest times to the present their common denominator has been their clean and as-new condition.
There are parallels with the previous auction of an engine collection in January 2004 at Christies in London when Miguel de Rancougne's formidable aggregate of exotic types was dispersed in four and a half hours. The same experienced team of organiser Jeremy Collins and photographer Mark Asher ensure a well illustrated and descriptive catalogue. Similarly, engines will be grouped to contain the volume in 232 lots, this time by Nationality, eg American, Australian, Czechoslovakian, English, French, German, Italian, Japanese and Scandinavian.
Keen collectors will find many desirable gems when the catalogue is established on the website, www.mellorsandkirk.com. The elusive Cloud Hurricane, one-off M.P.Lyon 5cc made for Bassett-Lowke, Allouchery Turbolid, Indonesian Boma, magneto equipped Hornet racer, Webra Boxer twin, Ghibli 5cc Italian diesel, Condor Copper King, Aero 35, fixed head 10cc Morin diesel, Danish Viking 2cc, Oliver 2cc Fury, and French Vega 10cc are random selections which emphasise the breadth of variety.
Among the immaculate flying models are ones bought-in, or made by Doug Walton himself and his friend Chris Edwards. The variety embraces the pre-war Premier Lyon and Diamond Demon to an original Stentorian, Mercury Aeronca Sedan, a Lysander and a list that covers all the British classics.
The 840 engines, about 40 flying models and accessories are to be auctioned on September 23rd by Mellors & Kirk at their Auction House, Gregory Street, Nottingham, located to the West of Nottingham City Centre, five minutes by taxi from the railway station and 20 minutes from East Midlands Airport. Precise location can be viewed on their website. The Email link is email@example.com.
Price Rise of Plan Book CD
A long overdue assessment of sales of the Motor Boy's Plan Book on CD shows that the price point established last October was insufficient to cover costs. Let me rephrase that: My Bad; I got it wrong and CD sales have been being subsidized by the DVD, which is supposed to pay for the web site. So sadly, as of August 2009, the price for the CD will rise by a modest $5 to US$20.00 for world-wide airmail orders, or US$15.00 for Australian domestic orders. With 105 pages detailing 13 engine designs, that's still under two cents per page.
Mr Taipan Turns 90
In the late 1940's, Gordon Burford decided he was going to become a model engine designer, builder, and manufacturer. He suspected he'd never be rich as some measure it, but he would be rich where it counted to him and countless Australian model makers thank him for his bold decision. Some more information on Gordon and his long career lies in the Engine Finder under the names Taipan, Glow Chief, Sabre, and GeeBee. Gordon will turn 90 years young on August 3, 2009 and I for one wish him many more... Happy Birthday Gordon!
More Barr & Stroud, Much More...
The call last month for anyone who could shed light on the SIC Barr & Stroud sleeve valve motor cycle engine plans elicited more responses than I'd have expected. First, Jan Tollerund (Norway) wrote telling how he had modelled the SIC plans in 3D CAD, in collaboration with designer Pieter Dekker before he passed away. Jan had started construction, but sadly, his project was totally lost in a workshop fire. Jan supplied the photo here which shows the example of the type built by John Parsons.
Then John Ramm (Australia) sent in a photo of the engine he had built from the SIC plans. John says that his B&S model starts easily and has nice, crisp, exhaust note. He noted that when running, it gets very hot, very quickly and is not a beginners engine as cutting the ports was quite a challenge. John confessed to stuffing up the first one, eventually filing them out which he says is ok for one, but not the way to go if faced with fourteen on a double bank radial. Regarding the plans and ports, his ports were per the plans and you can't argue with success, so both they and the timing can be asserted as acceptable, however John seemed to recall that there was a problem with the junk-head.
Another Norwegian, Gunnar Olsen of Micro-Hobby who supply micro CNC mills and custom R/C helicopter components, sent screen shots of the SolidWorks 3D CAD model he has made from the SIC plans in preparation for building his B&S model. His findings confirm John Ramm's recollections: when the sleeve-valve liner is at its lowest excursion, the junk-head ring is partially exposed. This is bad, but fixable. The other snapshot of Gunnar's model with the piston at BDC shows the liner at mid-stroke. There is very little room in the junk head with the liner at it's TDC position, so some juggling will be required to extent the liner height by a ring width or tow to keep the head ring inside the liner. Like most modern, parametric CAD packages, SolidWorks produces animations and you can watch a movie of the B&S sleeve valve rotating through a complete four-cycle on Gunnar's web site at the movies page. Be warned before you click the link though, the download is quite large at 44.5MB.
But wait, there's more! Brian Perkins, whose new web site was mentioned last month, sent a copy of information on the timing of the Bristol Hercules which he had obtained from the Bristol Trust while building his Aquila model. This shows a healthy 15° inlet/exhaust overlap, with the inlet opening 10° after BDC. And as a Last Word, Greg Kamysz (USA) who has also been modelling the SIC B&S with a view to construction, shared his extensive research on sleeve valve practice. This led him to Argyll Motors, a British motor car manufacturer whose production dates all the way back to 1900. Their website has a wealth of highly technical information on the sleeve valve. The paper by Archie Niven can also be found on the SAE Journal for May, 1927, if your local university engineering library has a decent archive.
No Thrill Bigger
After a short gestation of a mere two years, John Ward (USA) has finished his first engine, a ML Midge, from MEN plans. As little diesels like this will run forever on fuel vapour, John came up with a simple "tank" that gives him a 25 second engine run—just right for his little Dakota free-flight biplane. There is just no thrill like flying a model you've built, powered by an engine you also totally built yourself, and Mark Lubbock's wonderful little design has provided many with the opportunity to enjoy this unique experience for themselves. John says he has a video of the Midge and Dakota in action on UTube.
More on the Kemp Eagle
An extra photo of the Kemp 1cc Eagle from Adrian Duncan sparked an extensive revision of that page and got me all hot to draw full plans the little beastie (don't get excited; it hasn't happened yet ). Looking at Adrian's photo, I spotted what appeared to be an unusual but useful construction feature and persuaded him to take a screwdriver to the aged head screws. This uncovered an enigma to which Eric Offen has supplied the answer, if not the explanation. So click the link or thumbnail for a look inside this 60 year old side port with some remarkable similarities to the Weaver 1cc side port.
The 1945 "Scrapper" clack-valve ignition engine was one of the first engines selected by the Motor Boys as being unusual enough to be drawn up and included in the Plan Set Book. Bert Streigler made the sketches which I then turned into the CAD drawing set. Bert also drew up the even rarer drum-valve Super Scrapper. I started drawing this one too, but the set stalled over some problems, including how to retain the timer—a problem the designer never solved either as none of the ten or twelve suspected to have been made had a timer! There were other problems with the engine too, as detailed by Alfred R Dickau in the June 1985 issue of ECJ. Well, more data has come to light from a MEN reader, so the plan set is now almost complete and a Super Scrapper page prepared. You can reach it from the thumbnail of one of the remaining original engines, or through the Engine Finder.
New Books and Magazines This Month
Issue Number 19 of Model Engine Builder came out during July. Mike and Toni have put together a really good spread of topics for this one. The content ranges from engine, tooling, and gadget construction projects, to a workshop visit and simple die casting techniques. The IC engine is a twin cylinder, opposed piston engine featuring exposed crankshafts. The design comes from Doug Kelly and will be fully described on fourteen of the usual 3D CAD drawing sheets. This issue contains the first eight. The article concludes with a new, compact reference system to articles in previous issues that provide more details on a particular technique. For example: "Making Springs—#11,P-9" indicates that more information on that subject can be found on page 9 of MEB Issue number 11.
On the subject of making springs, this issue contains a nice little spring winder that for a modest effort in construction, will allow you to wind right or left hand compression or expansion springs. The device has a nice feature for setting the pitch of compression springs and makes it simple to wind them with "closed ends". The design comes from Dario Brisighella Sr. and lacks only a way of calibrating the tension applied to the wire during winding, although this would not be difficult to arrange.
In another article, Alan Suttie provides some details of how he built a fine example of the well known ETW Avling Road Roller without the use of castings. This is a very significant achievement, especially as Alan replaced the somewhat dodgy ETW reversing friction gearbox/clutch with a for-real, two-speed, fast-acting, cone-clutch 'box. He also replaced the original carburettor with a float chamber unit designed by Westbury for his 30cc Wallaby.
Issue 19 also has Part Two of Jerry James' investigations into the use of the ZX-12 alloy for casting small engine parts. Part One of this series appeared back in MEB Issue #16. Since then, Jerry has shown that the dies can successfully be made from aluminium and that is what this part describes. This is very interesting for two reasons. First, it is a bit easier to machine and polish the die parts. Second, Jerry found it was not necessary to pre-heat the die, making handling somewhat easier. Sounds like this would make a good way for producing a replacement die casting for something small but relatively complex like the tank top of a Milford Mite.
The issue also contains the names of some old friends. From Malcolm Beak, we have a Paddle Wheel Engine, then Ron Cairns is back with a description of Michel Arseneau's engines. Michel's latest design is still under wraps, but Ron provides conceptual drawings for the earlier RAD 3A that show the zero side-force piston arrangement. Be sure to visit Michel's website for more details.
I'll confess to being biased towards MEB. Issue #1 carried my construction article for the Mills 1.3 replica and I really want Mike and Toni to succeeded because I believe that they are helping the hobby and doing it in a professional and entertaining way. So if you are not already a subscriber, give it serious consideration. At the time this went to press, US Subscribers pay $39.95 for six issues. For Canada and Mexico, it's $48.00. Surface mail to all other countries is $53,00, and is for those who just can't wait, airmail delivery is $63.00.
Engine Of The Month: Milford Mite
Back in the January 2004 edition of MEN, Ken Croft dubbed the Milford Mite "...probably the worst diesel ever made in England". Ken has some very sound reasons for this call, and this month, Adrian Duncan and Kevin Richards give the poor little thing an intense scruit. The result? Well, read it for yourself and form your own opinion. I'd be tempted to say yes, it's horrible, but it is not lacking in a certain charm—but that could be a side effect of the old beating your head against a brick wall scenario occasioned by formatting the long and profusely illustrated HTML page!
Tech Tip of the Month
Chris Boll is the designer of this 1.8cc side-port diesel based on the ML Midge. His engine appeared in Aviation Modeller International magazine last autumn. Chril emailed during July asking for any information we had on a variable crankcase bleed backplate he had read about as made by AE Rivers Ltd for their 3.5cc Silver Arrow diesel of 1960. I'd heard about it, and David Owen had gone a step further, having actually tried it. Now you can read about it on the new How to make a (not very effective) Throttle page.