Model Engine News: March 2011


Special Features:

   Vale: Robert Reder
   Boll-Aero Gallery
   Members' Free Plan
   Titanium, Anyone?
   How did he do that?
   A New Hope
   Warel?
   Wen-Mac Remembered

Regular Features:

   Editorial
   New Books and Magazines This Month
   Engine Of The Month: AM .049
   Tech Tip of the Month
   Standard Stuff
Creative Commons License   

 

Editorial

What can I say about all of the continuing disasters that have struck our part of the southern hemisphere since I last wrote in January? The cyclone mentioned at the end of the last Editorial hit North Queensland and it was a doozy; category 6 only because that's as high as the numbering goes. Miraculously, no one died in the mayhem that ensued as it smashed into the coast and penetrated inland for hundreds of kilometers. Cyclones usually become rain depressions after crossing the coast, but not this one. Inland towns that have never contemplated having to cyclone-harden construction were severely damaged. With all this, it's a wonder that the only directly related death was the guy who locked himself up tight in his room to wait out the destruction with his 'fridge hooked up to his generator. If you'll pardon the pun, a dead-set certainty for a Darwin Award nomination, I'd say.

But it did not stop there. Disastrous bush-fires, triggered by a guy using an angle-grinder during a total fire ban took houses and lives in Western Australia. In Victoria, floods destroyed bumper crops before they could be harvested. Then there's the earthquake that has hit Christchurch, New Zealand which is just awful in a third-world kind of way. So far, the official death toll there is about 150 and set to rise. Although Australians and Kiwis have no great love for each other on the sports fields, off them it's another matter and on any day there will be tens of thousands from each country living in the other. We are separated by almost three hours of flight over water, but we are more alike in temperament, attitude, and sense of humor than any other two totally separate countries I can think of. MEN sends out deepest sympathy to any of our cousins in New Zealand impacted in any way by the earthquake.

Locally, life has returned to something like normal, but we'll be a long time recovering fully from our January floods. For one thing, Brisbane had a wonderful, efficient river transport system using big, very fast catamarans. They survived, but most of the terminals they use did not. The service was totally closed for weeks until the worst of the debris had washed out into the bay, but even though limited service has now resumed, it's a pale imitation of before due to the loss of the stations that will take a long time (and a lot of money) to rebuild. As forecast, the fights between the insurance companies and the flood victims have begun in earnest, and let's not mention the politicians who see all this as a way to make their name and rack up points for the next election. The Brisbane River is tidal. One polly (female) said we should let more water out of the dam so larger boats could fit under the bridges. There has to be a better system.

With all this gloom, it's good to get down to some good old model engines and engineering. This being the March issue, tradition demands a Birthday Plan Set as a gift from the birthday boy to our Members, which I hope they enjoy. In answer to the unasked question, The Beatles had a song especially for the occasion. I'm sure you know the one, and I shudder to think how old I was when it came out ...

Vale: Robert Reder (1917-2011)

For those with fond memories of Monogram plastic and balsa flying models—not to mention the beautiful hybrid plastic and balsa display models—you may be saddened to hear the Monogram Models co-founder, Robert (Bob) Reder died on February 20 at age 93. Bob had six children and numerous grandchildren. He had graduated as a draftsman in 1935 and began work with Comet Model Airplane Company in Chicago as a designer and draftsman. In 1945, shortly after World War II, Bob partnered with fellow model enthusiast Jack Besser to form Monogram Models Inc, initially operating out of his mother's basement and focusing on flying models and boats. In the 1950's Monogram was in the lead of the plastics fad, producing wonderful, complicated models, many with operating features. A major rival to Monogram in this field was Revell. They remained so until 1986 when Monogram was bought by a New York company who shortly after bought Revell and merged the two as Revell/Monogram LLC.

One of my early memories is of the Monogram Speed-e-built and Superkit rubber-powered models. These featured pre-carved, aerofoiled balsa wings hollowed on the underside, pre-colored die-cut balsa parts, and numerous plastic parts for scale appearance and extra weight. In comparison to the English Veron and Keilkraft stick-and-tissue rubber scale series, there was no comparison (well, maybe one: some of the English model kits could be made to fly passingly well). I especially remember the Monogram P47 and its scale four-blade prop. With a few hundred turns, that prop has almost good enough to move the model across a polished wood floor. Sure looked cool though. Vale, Bob, and thanks for all the fun your inventiveness gave to me and to many others.

Boll-Aero Gallery

Photos and details from two Boll-Aero projects arrived during February. Gerard Bleekman (Netherlands) has been constructing the new 4.4cc model being serialized by Chris Boll in Aviation Modeller International (AMI) magazine, and Harry Wilhelm (NY) has built one—pictured here—that incorporates quite a number of technical and cosmetic changes. It is a beautiful engine in my opinion, reminiscent for some reason of the ETA 15 diesel. Even more impressive, this is Harry's first attempt at engine making! Click the link the see more photos of Harry and Gerard's work, and download a set of plans for this engine.

Members' Free Plan

Speaking of plans, March marks my birthday and following our long-standing tradition, Members get a gift in the form of a set of CAD plans for an engine of some sort. This time, I've chosen a very early sparker, the Chunn Chum. This engine appeared in 1937, then again in 1937, and was finally revised with all new castings in 1937. Our plans reflect the second '37 model where the earlier fixed timer points are replaced by a very simple, sort-of adjustable arrangement. I rather like the designers' approach to arranging the bypass in such a way it was simple to produce with his limited equipment (see the Chunn Alternate Firing Twin page for details on Bob Chunn's engine building efforts). Members go to the Member's page for the pdf download. Non-members click the thumbnail for a large image of the General Arrangement sheet as a mild inducement to become Members.

Titanium, Anyone?

This may sound like overkill for shop-built engines, but I've noticed more and more that builders are producing some pretty serious engine intended for hard use, not glass cases. Then there are the folk who like to take a commercial item and get the absolute most out of it: light and stiff con-rods are one approach and where do you get light and Stiff? Titanium, of course. However getting hold of the necessary short of sneaking lumps of SR71 from static displays can be difficult. We received an email from the Titanium Metal Supply Inc asking for a "link exchange". We get a lot of these and most look like they are generated by a web crawler and sent out scatter-gun fashion in the hopes that 1 in 1000 may get results. The number of these has been on the increase of late and most go straight in the trash after a short look, just in case. I have no idea if Titanium Metal Supply will sell in small quantity, but their web site may be useful for those who know the name, but not a lot else about this metal. If any one has direct experience of this company, or tries them out, I'd appreciate an opinion to see if they are worthy of a link.

How did he do that?

Regular readers may remember that Charlie Stone (Aus) took up our challenge of "why doesn't someone build a MAN .19"? When Charlie started this adventure, a Gallery page was added to the MAN .19 Tribute page with some of Charlie's preliminary work. Well I had a phone call from Charlie the other day (Charlie is a Moderator on the Australian Control Line Nostalgia (ACLN) Forum for which I am the Webmistress, and after taking care of business, I asked Charlie if he'd progressed the 'case any? The response was, "oh yes, that's all done; I'll send a photo". Questioned further he admitted that manually blending the case with the cylinder had been chalenging. Well photos arrived and have been added to the Gallery page which you can reach by the link above, or by clicking the thumbnail of Charlie's absolutely stunning work on that blending job for what will be an outstanding engine.

A New Hope

After submitting the text and photos for this month's EOM, a surprise email arrived from Adrian Duncan with an update to his comprehensive series on the Japanese Hope Engine Range. The update is to Part 3: the Hope 60. Ok, that's cool. We do these all the time, but when I opened the Word doc, I found the new text was longer than the earlier article! The new data reflects new engines obtained by both Adrian and Alan Strutt (who wrote the majority of the original Part 3). The previous link and the thumbnail will take you direct to the new material, but you can always scroll up to refresh your memory on the original story—which has not changed.

Warel?

David Owen keeps coming up with unusual, or perhaps unique Australian model engines. Last month we saw the DS 1.3 diesel. This month it is a 2.5cc diesel neatly inscribed as a Warel. When I opened his email and before reading the text, I asked myself why David was sending me photos of a Miles Special, then the differences clicked in and I knew I was looking at something new. So click through to the new Warrel 2.5 page and if you can provide more than the little we know, we'd appreciate hearing from you.

New Books and Magazines This Month

New onto the already groaning shelves of The Library during February was Issue #23 of Model Engine Builder. Like all craft magazines, it contains articles that will interest you, and ones that won't. Or perhaps I should say "won't yet". Over the years, you will find that your focus and interests change, so even if today, a linear drive vacuum engine does not appeal, it's still good to know it's there because some day, this engine, or some aspect of it may be just what you need. I'm currently reading a series of articles in old copies of the Model Engineer that I've had for decades and which have never held the slightest interest to me before, so who's to say?

Other highlights (to me) in this issue were the piece on spring winding by Dwight Giles, and the continuing series on the mechanics and geometry of cam grinding by Carl Wilson. The center-fold is Ron Colona's jaw-dropping quarter-scale Novi V-8. For the beginner, MEB editor, Mike Rehmus, continues his build of my Humbug design. Mike is using a Sherline tabletop lathe and uses this as a vehicle to explain and illustrate useful beginner techniques. Having simple, basic techniques explained is good. Having them illustrated is even better, but having then explained and illustrated in the context of an actual beginner project is the bee's knees. Well done, MEB!

Engine Of The Month: AM 049

That Adrian Duncan character is at it again with yet another chapter in the saga of British-made 1/2A engines. This time it's the Allen-Mercury (AM) .049 and yes, you could be forgiven for thinking, "hang about, that's a Wen-Mac 049"! Well, as Adrian carefully documents, it is, and it isn't. Hard details of what was made where and by whom are just not available, so Adrian relies on logical deduction, material from the model press, and a couple of guesses. As always, we are always willing to revise assumptions if anyone wishes to provide convincing evidence to the contrary. Even hear-say can be of use as it can lead to a connection we did not know about, so don't be shy. Email us through the address at the bottom of this page. We hope you enjoy our treatment of the AM .049 and where it fits in the saga of 1/2A model engine manufacture in England.

Tech Tip of the Month

I was quite surprised and greatly pleased by the response to last month's rather simple tip. Although it seemed utterly basic to my way of thinking, several readers emailed giving thanks for the tip which in one case had been put into practice immediately with perfect results. Spurred on by this evident need for beginners' tips, and prompted by an article in the issue #174 of the Model Engineers' Workshop which arrived this month, here's another which even though not directly related to model engine making, is one which may well face any model engineer just starting to make beautifully machined scrap.

For many just starting out, their equipment will be a lathe, and possibly a drill press. Any milling operations will therefore be carried out in the lathe using a vertical slide, or carefully selected packing pieces. The lathe is the most versatile of tools and while it can be ab-used as a mill, precautions are required:

  1. The lathe saddle is much lighter than even the table of small milling machines and will distort easily, especially if equipped with T-slots like the Myford. So when milling in the lathe, tighten up only enough to firmly hold the work. If you over-tighten, the distortion may prevent the cross-feed from working smoothly, or at all!

  2. Keep you old business cards and collect those being disposed of by friends and colleagues. These are great for packing and not only protect the work, but increase the friction between work and clamps, fixtures, etc. The result is a set-up less likely to shift under cutting forces that requires lighter clamping than a similar set-up with no card. Even plain paper is good for this.

  3. Assuming you are using a vertical slide, after setting the depth of cut, preferably with a graduated feed on the lead-screw, lock the saddle and tighten the cross slide gibs. If you don't, expect to see the cross-slide dance around in a most alarming way while milling! The work finish will reflect the lack of rigidity.

  4. Milling cutters are (mostly) helical, like a screw, so when they are subjected to load, they will tend to act like one. If held in the long-suffering three-jaw self-centering chuck, a cutter is highly likely to screw it's way out of the chuck with disastrous results to both work and cutter. If you have to use the lathe this way, invest in a real milling cutter holder, preferably of the "Auto-Lock" variety which takes threaded cutters. While these are a bit more expensive that the plain-shank "disposable" type, once locked in automatically, your cutter and headstock are totally rigid, provided that is, the cutter holder is retained by a draw-bar.

  5. Make yourself a draw-bar with a nice big knob on the end. This can also be used to knock a dead-center out of the lathe headstock with a slap of the palm on the face of the large knob.

This last one is the one that drew my attention while scanning the content of MEW #174 (remember that?) as it made me recall a spot of beginners' ignorance I indulged in almost twenty years ago when I was using my lathe and a vertical slide as a mill. I had already experienced hint #2 and discovered the cure of hint #3. I'd also experienced first-hand the trouble of #4, destroying two brand new cutters trying to use them to what the specs said they could cut (0.030" I now consider a bold milling cut for a lathe set-up). So I'd invested in a nice MT2 Auto-Lock chuck and after another disaster, decided it needed a draw-bar.

So I implemented hint #5. My shop-made Draw-bar is used these days for knocking out centers, but occasionally I do still use MT2 tooling in the headstock spindle. Finger pressure is enough to really clamp up (clean) 2MT tapers and a slight slackening of the nut and slap with the palm of the hand is all that's required to break the taper lock (ok, occasionally the plastic mallet is called on, but not often, really). The end nut is made a large diameter purposely to ease the pain of slapping it. It screws onto the shaft and was initially locked in place by a single grub screw tightened onto a flat filed on the threaded part of the shaft. The screw came loose almost immediately, no matter how often or hard it was re-tightened (the knob has been partly unscrewed off its shoulder for the photograph).

A second grub screw was fitted diametrically opposite the first, just like the MEW design. Now both screws came loose instantly! Oh well, the flats on the shaft prevented the thing actually unscrewing, but it was still a puzzle. Maybe I should have just made the thread a tight one, or Locktite it on, but that would prevent quick removal which I've had need to do on occasion.

The answer was spotted in George Thomas' Model Engineers' Workshop Manual. George describes the problem and the solution: place the two grub screws at 90° to each other, not 180° and they will remain tight forever as they are working with each other instead of against. This was done and the problem went away. I'm almost tempted to write to the MEW "Scribe a Line" agony column about the flaw in the #176 draw-bar design, but that column is permeated by "people who know better", so I'll leave discovery of the problem and cure as an exercise to the students, but at least we MEN readers can be smugly content, knowing the problem and cure. Obviously this applies not only to draw-bars, but to any device secured to a shaft by grub screws.

Wen-Mac Remembered

Given Adrian's piece this month on the English Wen-Mac 049, I thought it would be good to give some background on the company itself. An good article on them, produced after a site visit, appeared in American Modeller, dated September-October 1964. This was Wen-Mac were at their peak, so remember as you read our OCR scan conversion of the Wen-Mac Visit that you are time-travelling to nearly half-a-century ago!

I have mixed memories of the Wen-Mac SBD Dauntless plastic RTF which I received for Christmas in 1960, I think it was, on the eve of starting High-School. That Roto-Matic 049 sure started first zing, much to my delight having had less happy times with Cox and OK 049's. To the probable annoyance of the Chernich Christmas Gathering of the Clan, I continued to start it up all day long until my uncle took pity on me and we went down to the local park where the thing resolutely refused to start at all. I finally did get it airborne. I don't recall when, but do remember it had to be off concrete as it would barely roll forward on grass. Anyway, the thing wallowed around like a pig and was so much of a handful to keep in the air, I never did get to "drop the bomb". It may have done better if I'd halved the supplied line length, but even then I was mindful of the "brick on strings" label. Rather quickly—again as noted by Adrian—the Roto-Matic spring gave up the ghost and I went back to my smelly but reliable diesels in less attractive but better behaved balsa airframes.

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