Having now tried it out for a month, I have to say this retirement gig is rather good! I've managed to accomplish several things that have been on the to-do list for a while (better part of a quarter-century in one case—see this month's Tech Tip). Another was to get some paint on the racer and do the little tasks like making the fuel cut-out (activated by a quick pulse of full down elevator), and solder up a fuel tank. Those two little tasks alone required about as long as it took to build the airframe, or at least, that's what it felt like. But as you read this, the model has had her first shake-down flights. Result: the cut-off works, and a wheel fell off (I'd forgotten that the bolts were not long enough to fully engage the nylock nuts and needed to be replaced). However it was fast and I could put it down right on top of my pit-man with no difficulty, so it all looks promising, so far.
On a different note, an interesting and somewhat amusing waste of time occurred during the month. It started with a respectfully worded email to me as the registered administrative contact for the modelenginenews.org and .com domains, alerting me to a situation in China where a "customer" had expressed the desire to register the domain modelenginenews.cn. The mail went on to say, "we find this name conflict (sic) with your company name or trademark", and asked if I had a business partner in China. The signature block identified the sender as "General Manager, Shanghai Office (Head Office)"—notice that no actual company name was provided. Who in their right mind would want the domain "modelenginenews.cn"? Detecting a feint whiff of the proverbial rat, I responded, saying that I had no business connections in China.
Not long after, mail arrived from a different person in China stating his intention to register the domain using the services of the sender of the first mail, saying "We think this name is important for our products in Chinese market (more sic)". Even though the oder of rat was now distinctly stronger, I checked what it would cost me to secure the .cn domain through the services of the first sender. The cost per year was more than I pay per five years for the .org and .com domains together. Although the scam detector was now screaming in my ear, I responded respectfully to the sender of the second email, saying in essence, "Go right ahead, Sunshine. Knock yourself out".
Very soon after that, another email arrived from the original "Network Service Company" strongly suggesting that to protect myself, I quickly register not only modelenginenews.cn, but also the .org.cn, .com.cn, and .net.cn domains, all at merely ruinous rates! By this time I'd done some digging into scams like this and found several, though none with the "names" being used in my case. Concluding that it was past time to bury that dead rat, I've simply ignored the last extortion demand. I think that I (and indirectly, you) are safe from suddenly being deluged and confused by products from a Chinese company using the "modelenginenews.cn" domain name.
I won't bother to enumerate all the red-flags in this saga which indicate that it's a scam to make unsuspecting Westerners, perhaps a bit in awe and afraid of the size of the emerging Chinese market, part with significant money for no return, at very little effort on the part of the perpetrator. As I said, I'm more amused than alarmed and although I did waste some time dealing with the problem which I'd rather have spent doing other things, it's no biggie. That said, I can see how it would work in some cases, and that angers me a bit. Still, it's good to unload and place on the web (and Google) this warning of Yet Another Way which enterprising Chinese persons have found of using the Internet to make a quick buck .
Chenery Plans Availability
The model engines designed by the late Les Chenery are still popular designs, as evidenced by Les Stone's recent completion of the Gnome Rotary from Chenery plans. There are three scale and two bespoke designs in the Chenery range. The scale engines are the nine cylinder Gnome rotary, the three cylinder Anzani radial, and the two cylinder Aeronca opposed engine. All of these are four-stroke engines designed for spark ignition, as were the prototypes. The non-scale engines, also four-strokes, are a V-twin, and a side-valve single. Details of who to contact regarding them can be found on the Supplier page, which has been updated with amended postal and email contact details as the plans are distributed by Les' son, John.
All of Les Chenery's engine designs have appeared as serialized articles in the English magazines Model Engineer, and Engineering in Miniature. Information supplied to us by John contained a list of the relevant issues. This is useful information, so is reproduced below.
|ME 4161||ME 4022||ME 4189||EIM 1983-12||EIM 1988-05|
|ME 4163||ME 4024||ME 4191||EIM 1984-01||EIM 1988-06|
|ME 4165||ME 4026||ME 4193||EIM 1984-02||EIM 1988-07|
|ME 4167||ME 4028||ME 4195||EIM 1984-03||EIM 1988-08|
|ME 4169||ME 4030||ME 4197||EIM 1984-04||EIM 1988-09|
|ME 4171||ME 4032||ME 4199||EIM 1984-05||EIM 1988-10|
|ME 4173||ME 4034||ME 4201||EIM 1984-06||EIM 1988-11|
|ME 4175||ME 4036|| || || |
|ME 4177|| || || || |
|ME 4179|| || || || |
|ME 4181|| || || || |
A New EDM from Ben Fleming
Some time ago, I found myself in need of a way of removing a broken tap from a blind hole. The full story can be read on the EDM Saga page, but briefly, it resulted in building a "plunger" type EDM to a design in a book by Ben Fleming. Ben's design remains very simple and effective, but as he wrote in his book, uses a "brute force" power supply to create the plasma which does the machining. For several years, Ben has been working on a more sophisticated machine which uses shaped pulses rather than a simple RC circuit (read the review if this does not mean a lot to you). The new machine has a new ram design and supports depth control, if desired (trust me, you want this).
Ben's new design is now released, again in book form, with an optional PCB (Printed Circuit Board) which will significantly simplify construction of the electronics and reduce the chance of a wiring error. You can obtain your copy by emailing Ben at email@example.com. The book alone is US$50.00 to any US address, or $57.00 for the "Rest Of World". The PCB is $38.00 in the US, or $42.00 elsewhere. Ben accepts PayPal and be sure to mention Model Engine News when ordering! More information after I receive the review copy .
Ready To Run Stirling
If you've ever wanted a model Stirling engine, but lack the workshop or time to build one from the myriad of designs available, the Willstead SE1-10 may be what you are after. This engine, machined from aluminum, is complete with alcohol burner on a polished wood base. The flywheel diameter is 98mm (3-7/8") and will turn somewhere between 600 and 800 rpm, depending on wick height, atmospheric pressure, etc. Willstead (Steve Lustead and John Williams) can also supply finished flywheels, alcohol burners and other accessories for scratch builders. Their website has been added to our Links Page.
Precisely what is Schnurle Porting?
Last month we presented Garofali's 1962 patent for transfer porting of model engines. This has led to some discussion between David Owen, Gordon Cornell, and myself regarding just what is meant by so-called Schnurle porting? The Garofali patent uses angled transfer ports to achieve Loop Flow without a piston baffle; so does what many refer to as Schnurle porting. The use of Schnurle porting has also been used to define a cut-off point for an engine's elligibility for certain vintage events and generally is believed to be characterized by a third "boost" port which introduces a spin or swirl to the transfer charge. As Gordon points out, some individuals do not appear to appreciate that this port is not an essential part of the "Schnurle" claim (there are OS engines without this port). The "boost" port opens substantially after the primary inlet ports so the available pump pressure is marginal. After transfer begins, but while this remains closed, a high velocity of gas is maintained. When the boost port opens, the added port area permits flow to continue at the now lower pressure difference through the ports. What it actually does is to scavenge the cylinder local to the port at low pressure with the intended outcome being that the charge does not reach the opposing exhaust port. What must be appreciated is that the crankcase pump does not have sufficient capacity to scavenge the swept volume of the Engine. This indicates that the "boost" is primarily a mixing process.
Our conclusion (so far) is that for "Vintage" competition purposes, defining "Schnurle" porting as a cylinder having a third "boost" port will allow the use of some very powerful engines which have angled transfer (such as the Super Tigre subject of the Garafoli patent). This is convenient, but open to dispute due to the looseness of the definition for what precisely is, or is not, a Schnurle ported engine! If you are aware of any attempts to define Schnurle porting with some precision, we'd like to hear—and maybe argue about it!
With the demise of Myford as a lathe manufacturer, what if anything can take up the pace as a good model engineers' lathe? One suggestion is the South Bend SB1001. This lathe has some excellent features—many better than the Myford Connoisseur in fact, but it also has some serious draw-backs such as no quick-change gearbox and a limit of 32TPI on how fine a thread it will cut. Moving up one model in the South Bend range to the SB1002 addresses both of my quibbles, but introduces another: this machine is not small and may tax the space available for a hobbyist lathe. Still, I've said before, buy the biggest and best you can afford and accommodate. South Bend has a reputation for reliability and precision, so they are certainly worth considering.
New Books and Magazines This Month
This retirement lark is pretty good; during the past month I've indulging in a guilt-free "Jobs pig-out", re-reading several of the rather surprising number of books The Library contains on the subject of Apple Computer Inc and Steve Jobs. I suppose I'll have to buy the new one by Walter Isaacson when it comes out later this month, though I do tend to "trust" un-authorized biographies more than the authorized variety, especially when the authorizer appears to have possessed a well documented and extremely effective personal reality distortion field! Be all that as it may, the history of microcomputers is not the prime subject for this web site, so best I suppress my little personal addiction and find something more germane to write about. Hmmm. Ah-ah! I've got it! Harry Higley!
If you say "who?", or sort of vaguely remember the name, Harry Higley wrote the "Round & Round" column for Model Airplane News (MAN) during the mid-1970's. If you can't guess, Round & Round was dedicated to control line matters, but Harry's interests extended way beyond that and he soon began publishing books and selling strange but useful accessories to the R/C modelling trade under the name, Harry B Higley and Sons. This business operated and prospered for about thirty-five years. By an odd coincidence, Harry retired last month (October, 2011) when all assets of the business passed to Sullivan Products.
The book I've chosen for review this month is Harry's engine book: Harry's Handbook For Miniature Engines, Harry B Higley and Sons, Inc, 1980 (no ISBN). The book is soft covered, magazine sized, with 128 pages, illustrated by exceptionally clear photography (black and white only). The text, underscoring the period when it was produced and the size of the market, is not typeset. It uses something rather like a fixed pitch, Courier-like font (with serifs), possibly done on a primitive word-processor. Generally, the layout places text on the left with related, numbered pictures on the right, although there are instances where both pages are plain text. The writing style is very clear and easy to read with an absolute minimum of mathematics and technical detail. This is not to say the material is superficial. Harry has done a good job balancing what a modeller needs to know to operate and maintain his engine, without losing his audience in jargon, or advanced and seldom required information. In the introduction, he gives the aim of the book as:
- Improve [engine] performance,
- Lengthen their useful life,
- Help diagnose problems,
- Simplify repairs,
- Reduce costs, and,
- Minimize frustration
The book is divided into seventeen chapters with two appendices. The structure is about what every model engine book author before and since has used with chapters dedicated in sequence to basic theory and design, fuel, propellers, starting, break-in, throttles, cleaning, maintenance, and hop-up. Harry restricts himself to glow-plug engines of modern (late 1970's) vintage, although he does include some photos and comments on spark-ignition engines in his chapter describing engine development. The chapters on maintenance use a reed-valve Cox 049 and a ball-race K&B 61 FRV as subjects. The photos in these (separate) sections are exceptionally clear and fully illustrate how to completely disassemble and reassemble the engine. I'm in almost 100% agreement with his techniques, feeling only a little uneasy about the use of needle nose pliers to coax the rod big-end off the crankpin, and the lack of caution used when re-inserting the ball races in the 61. But I may be overly cautious in this regard. The K&B 61 is after all, a sports R/C engine, not a racing or high-speed ducted fan donk where even slight ball race misalignment can rob you of the engine's full potential.
In a lot of ways, Harry's Handbook For Miniature Engines is similar to Dave Gierke's Two-stroke Glow Engines book. of the two, I'd rate the Gierke book higher because of the increased coverage of theory and development history, but as stated in Harry's introduction, that was not his intent. When it comes to operation and maintenance, both books are about equal and some readers may prefer Higley's direct and simple approach to the subject over Gierke's more advanced and hence more "dense" text. But both are illustrated with outstanding, clear illustrations, coupled to sound, practical advice. Harry's Miniature Engine Handbook is out of print, but copies are not hard to obtain through Amazon or ABE. I rate it four and a half stars, only because I gave Gierke's book five and have already said that to me, it's not quite that good, but beginners could do a lot worse than to read this one .
Engine Of The Month: The Classic MVVS Glow Engines
The MVVS range was one I'd rather ignored until the late Russell Watson-Will demonstrated his Figtree Pocket Twin to me—the noise and power was frighteningly impressive! Russ point blank refused to have anyone say he'd designed the engine, saying he'd simply stolen ideas from others and combined them to his requirements (Australians tend to be rather modest and Russ was more modest than most). As the cylinders of his engine are a direct copy of those used in a MVVS diesel, I decided these engines deserved closer attention. Indeed, I challenge any engine builder to examine the design and engineering of a typical MVVS and not be impressed. This month, Adrian Duncan presents a history and critical examination of the "classic" MVVS glow-plug engines: be prepared for a few surprises.
Tech Tip of the Month
What do you do with a broken Myford-Dixon tool holder? In this case, something I've been promising myself for the last quarter century: turn it into a permanent holder for a DTI so it can quickly be used in conjunction with a "wobbler" to center work on the faceplate, or in the four-jaw chuck. For absolute precision when used this way, the DTI probe needs to be right on the lathe axis. Having said DTI pre-mounted in a quick-change holder that's already set on center height saves a lot of time. It also makes me feel better over the otherwise loss of a quick-change holder due to a crack and over-tightening. The holder was made from 3/8" plate and the end rounded in the way recommended for conrods.
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.
- We have updates to the reviews of the K Hawk, and the K 2cc Models.
- An alert reader wrote to inform us that the terms "mill" and "slot drill" as applied to four and two flute milling cutters (respectively) had accidentally been transposed the first time they are described in the Kitting Up (1) article. Oops. Fixed. Thanks! Luckily I got it right later in the same article, so no crow sandwich required.
- The unidentified engine in the AHC Model Gas Engine Handbook review last month was also a Louis Loutrel design which first appeared in the April 1933 issues of Model Craftsman Magazine under the heading A 3/4" by 3/4" Gasoline Engine. Thanks go to John Ward for this information.