Model Engine News: August 2013
Rear Exhaust Engines for F2B
Another Member of the Clan
Junior Brown Junior
New Books and Magazines This Month
Engine Of The Month: H&R Rattler
Tech Tip of the Month
Unless otherwise expressed, all original text, drawings, and photographs created by
Ronald A Chernich appearing on the Model Engine News web site are licensed under a
Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.
Burr, burr, and triple BURR! I've been freezing my bearings off here for the past month in a winter the like of which I can't remember since, well, the last time we had a winter like this! Trust me, it was not recent. All right, so the sad lack of meat around my bones may be a contributing factor, but Ruthie says it's cold too and she generally complains about heat, not cold. Did I mention it's wet as well? Seems we alternate between a couple of days of crystal clear blue skies with night time temperatures falling below 10 °C, and miserable grey days with occasional rain. At least those keep the temperature up, a bit. Now I know a lot of you out there will be looking for a calculator to see what 10 °C is in Fahrenheit (it's about 50 °F) and will be wondering what I'm making a fuss over. It's a lifestyle thing. Brisbane is supposed to be sub-tropical, so homes have practically no heating and the only insulation is aimed at keeping the heat out, hence my grumble—and seeing that I've sworn off politicians and Microsoft, a codger needs something to grumble over.
So to take my mind off it, I'm building a new model; one I've always wanted to make, which is small enough it does not need the giant build bench in the freezing workshop—a Don Still Stuka Stunt, from the RSM kit. Seeing as I've had to acknowledge that my days of mobility are coming to a close, I've decided to make the most of what I've got, while I can. I've also ordered a giant diesel Porsche truck to cart it (and another model or two I have in mind) around in. Ruthie gets the Boxter and we sell her old Merc, which has surprised me in how little a 2002 C-180 is worth these days. The truck is being built to spec and should arrive in November, which is something to look forward to, along with the warmer weather.
On the model engineering front, it's been way too cold and miserable to do much except make a C/L venturi and NVA for a club member, and contemplate a prop driver for a GMA Jett 60 RE which is missing same (see second photo in the first News Item). Not a hard job, but I'm guessing that it may have had a small labyrinth seal at the back; anyone have one they can send a photo, or dimensions of? In fact, this need makes a neat segues into our first news item, or should that be anti-news item...
Rear Exhaust Engines for F2B
My flying buddy and I both have Ted Fancher designed Trivial Pursuit kits (RSM, again) stashed away for a rainy day. I have an engine for mine, but Van does not and decided to go looking for a new, modern, all-out competition standard, F2B (C/L stunt) rear exhaust 60-65, with or without pipe. Result? Nothing, Zip, Nada! The first choice would have been a Randy Smith PA65, but seems he's not making them anymore, or the waiting list is so long and select that Van and I will be dust by the time he reached the head of the queue, Randy too, I expect. Next option was a RO-Jett, but emails to them from Van and MEN went unanswered, so draw your own conclusions. Merco is gone, MVVS is not doing anything like that anymore either, and the odd-balls like Double-Star etc have all disappeared. This seems to restrict the field to the Stalker 61 RE 2-4, but Van has heard so many complaints about quality control and poor performance of current-day Stalker engines that he is not prepared to risk it. I have to say I've been happy with mine, even if it did arrive with half the head bolts missing!
So where are we on competition level F2B, rear exhaust 60's these days? Seems like nowhere is the resounding answer (the quiet answer is electric, but more on that later). This is perhaps understandable. Let's face it, people make engines to make a buck, and making a reliable, dependable, powerful, competition-level F2B 60 requires a lot of know-how, quality, and dedication. All that effort to service a market, the size of which which might never reach into three figures. Some top precision aerobatic fliers are using big 4-strokes. Many are clinging to their stock of PA whatevers, obtained back in the good old days. Van finally managed to score a GMA (Aldrich) Jett 60 RE, missing the prop driver, exhaust header, and needle, but showing relatively little use. This was pure luck. If not, the next answer would have been an ECL (Electric Control Line) setup.
It feels like sacrilege to write this, but ECL at the F2B competition level now has a LOT to recommend it. No CG change with fuel burn; perfectly consistent engine run, every time, regardless of density altitude, temperature, humidity, and phase of the moon; no gunk to wipe off, meaning lighter finish and no fuel proofing worries; use of reverse rotation (mixed blessing), no vibration, so lighter structure and overall weight; speed controllers that produce 4-2-4 break-like characteristics; no more fuel mixing and problems obtaining nitro and good castor, etc. Balance that against the high cost of entry—although not that much more than a pro RE glow setup if you exclude the charger and some extra battery packs—the time you'll have to invest in the learning curve for new technology, and the danger explicit in in all powerful electrics during operation and charging and transport of LiPo battery packs. Then there's the loss of "excitement" that comes from a model internal combustion engine, and the sense of achievement when everything comes together just right—not to mention the sound (muffled, of course) of a stunt engine switching during maneuvers, or a pipe singing on tune.
Did you know that the current World Champion in F2B won the title with ECL in a specially designed stunter? Sigh... I'm calling it a sign of the times and the inevitable march of progress. Many ask how many flying sights would have been saved if we'd had electric power years ago. I suspect the answer is none at all; land developers will win every time, but the arguments "for" are compelling. So much so that the Precision Aero 51 I'd ear-marked for my next serious F2B model (the Trivial Pursuit, mentioned above) will be staying in its box and I've got a .46 cuin equivalent ECL setup on order (from RSM). Now you can really say I've gone to the dark side!
Footnote: as I'll be the muggins making the missing prop driver and exhaust header for Van's Jett-GMA, if anyone can provide a photo, or dimensions, it will save me some work and be greatly appreciated.
Now isn't that neat? It's a sectioned Parra team race diesel which some deviants use in combat models (I'm being rude; Parra actually make a combat version and the short, semi-protected NVA makes the engine somewhat "vertical arrival" resistant). Note the neat push-pull contra-piston setup, the beautifully contoured transfer passages and venturi profile, with the fuel spray passages just under the minimum diameter location, and the crescent cutout in the piston skirt to clear the crank web at BDC. The image was provided by David Burke of Adelaide Aeromotive, who added that Alberto Perra actually offers these for sale. For some info on Parra engines, see clubtamaran.
Speaking of David Bourke and Adelaide Aeromotive, David sent me this photo of some liners and cases for the Taipan 15 TBRD Mk2 reproduction. These liners are what he calls the "Tool Room Specials"—parts that precede the production ones which are yet to get under way as he is still fiddling with the manufacturing method. The Specials will be used for the engineering mockup, and to produce first ten samples. The Mk2 engineering mockup crankcase can be seen to the left of a Mk1 Production case. David has decided to place the emphasis on the Mk2 so as to provide something that will fit into a Vintage Team Racer, whereas the Mk1 was more about painstaking originality, adding that no doubt Gordon would have done something like this after the first pre-production samples anyway. Incidentally, there is now a fairly decent Wikipedia entry for Gordon Burford. This includes a chronology for Gee Bee, Sabre, Glow Chief, and Taipan engines. Naturally, Maris Dislers' Taipan book is mentioned, and the entry also references MEN and links to our Sparey 5cc Diesel page, which is really good to see.
Another Member of the Clan
Last month, we had a picture of the 0.24cc Clanford Clan built by Mike Walker (USA). This arrived late in the month and managed to block my memory that earlier that same month, I'd received pictures of Yet Another Clanford Clan, this one built by Rob Jenkins (Australia). Sorry, Rob, especially seeing as you and Chris Boll so generously made your BJ Cicada plans available for all readers of this web site. So better late than never, here is Rob's taking on the little Clan. He reports that the cylinder to crankcase seal gave him some trouble—not unexpected as this is one of the design failures of the Clanford engine; uneven torquing of the two head screws can ruin even an otherwise excellent fit.
Tha major difference between Rob's Clan and Mike's is the tank top machined from black plastic, and the clear tank bowl on Rob's version. If you look at the actual Clanford Clan, you'll see this is very close to the injection molded parts Clanford used, the difference being the pressed in brass needle holder on Rob's engine. Rob followed the MBI plan with conventional prop driver knurling. Clanford's engines used a diamond knurl here, which I was too lazy to draw, so all builders are excused. Extra points awarded to those who figure out how to plunge knurl a diamond knurl on a flat plane!
Junior Brown Junior
Prolific builder and fellow Motor Boy, Les Stone, has completed another of those things sitting under his bench, this one having been there since 1986. It is a scaled down replica of the Model "D", Brown Junior, built from a kit provided by Roger Schroeder. If you click the thumbnail image, you'll end up at the Les Stone Tribute page entry for the Jr Brown Jr. We've also added an image of the engine to the Roger Schroeder Tribute page, thus starting a whole new row of images, so if anyone else out there has completed a Schroeder Classic Engines kit and not sent us a photo for the page, we'd certainly welcome it.
I love all clever model engineering, no matter what it is. Way back in the 1970's, an American control line stunt flier (they'd say "Precision Aerobatics" today) named Al Rabe stunned the competition field with a series of semi-scale stunters. What was shocking was that these were closer to the "scale" part of the name than anything before, yet were competitive enough to make him a three times AMA National Champion, be awarded the Walker Cup twice, and place second at the 1978 World F2B Championships. His subjects were the P51 Mustang, the Grumman Bearcat, and the Hawker Sea Fury. All featured light but effective shock-absorbing undercarriage legs, which Al believes results in a points edge through a reduced tendency to bounce on landing. Strangely, these never really took-off (oops, sorry ) with other fliers, except for those who have replicated the models to Al's designs. The image here is the Sea Fury gear, from an article titled "Go for Broke" which appeared in the March, 1973 issue of American Aircraft Modeler. Normal "torsion" mounting took care for fore-aft and sideways loads, the sprung leg handled up and down motion. Note the way the tubes which act as bearings are figure-8 wrapped and soldered. A very neat job, but it is difficult and time consuming to get neat results like this.
Now why am I mentioning this? Well, that Mustang has been Yet Another on my must build, someday list, ever since it was first published, and I noticed a recent ad for laser cut ribs and fuselage formers for the model. With this was a note that parts for Al's simplified, new millenium version of the gear which uses metal plates in place of the figure-8 wraps to position the bearing tubes could be bought from Dirk Tollenaar. Dirk, if you remember, supplies the Bob Shores' PeeWee V4 casting kit, and had been asking after my well-being only days prior to my noticing that he's obviously branched out a bit. Well done, Dirk. Contact him if you ever get the urge to build a Rabe shock absorbing undercarriage and save yourself some time and effort using ready made parts for the simplified design.
New Books and Magazines This Month
The library did gain a pound or two this month, with all new books being inter-related and associated with my current passion, namely the Ta 152. Sadly, none came close to a five star read, IMHO of course, but that's life when you select and order on-line.
First we have, Design For Flight: The Kurt Tank Story, by Heinz Conradis, translated from the German by Kenneth Kettle, Macdonald and Co, London, 1960 (no ISBN). This book was first published in German, by Musterschmidt-Verlag, Gottingen, as Nerven, Herz und Rechenschieber, which translates as Nerves, Heart and Slide-Rule, 1955, which I judge now as the better title. It is the biography of Professor Kurt Tank, the chief designer at Focke-Wulf during and before World War II. The author, Dr Heinz Conradis worked with Tank and had access to him in the writing of this book, which spans 246 pages, with several photographic plates (black and white).
The story, like most biographies, introduces the subject's ancestors in context with where and how they lived. In the case of Prof Dr Dipl-Ing Kurt Waldemar Tank, his father had been a career military man who on retirement, became an engineer. At the outbreak of The Great War (WWI), Tank enlisted in the cavalry, like his father. Seeing little chance of a commission on the Eastern Front, he transferred to the Infantry and was a lieutenant before he was twenty. Having been fascinated with flying since boyhood, he frequently submitted requests for transfer to the German Air Force, but nothing came of these. Years later, his battalion commander told Tank that all of his requests had gone straight in the bin, explaining the a commander has responsibility to his officers, and that Tank seemed the "sort of chap who would have gone and killed himself in some plane or other, and [you] would not have been alive to do any flying after the war at all." I detect a certain British flavor to that translation, but the sentement was a good one and Tank did in fact gain his wings while studying engineering after the war.
To say that flying was a passion for Kurt Tank would be an understatement. Here is the ultimate test pilot, a man who has designed the aircraft (or led the team which designed it), knows precisely what to do to evaluate the performance, and does it! This extends all the way from the German radial and inverted V powered FW 190, to the jet powered Argentine Pulqui (developed from the Ta 183 for President Juan Perón), and the Hindustan Marut fighter-bomber, developed for President Nehru.
He also flew his Ta 154 Moskito, a very advanced all wood, two engine fighter-interceptor. This aircraft never really saw full service as the only factory able to produce the glue used in its construction was accidentally bombed out of production by a British night bombing raid. The book contains a photo of the forward section of a Ta 154 apparently being recovered from a lake. Actually, it had been towed underwater at a speed where the water produced the same load on the structure as calculations showed it would be subject to when firing its nose mounted cannon at maximum speed as no wind tunnel existed which could be used to demonstrate the structure possessed the required strength. Tank's idea; very ingenious.
I'm not sure what I was looking for in this book. Technical insights, probably. Well there was a few, but they are at a rather basic level as the author has set out to make the subject matter readable by the layman. I had already known that Tank was a pilot, and an active one, flying with the unit that undertook "base defense" for the Focke-Wulf factory, even after the Reichsluftfahrtministerium (RLM, the German Air Ministry) had issued an edict forbidding him to do so. In the biography, I discovered that before WWII, he had participated as the pilot in record setting attempts, and post WWII, flew his jets at public demonstrations. Kurt Tank died in 1983 at the age of 85, having returned to Germany in the mid 1970's. I learned a lot about the man and a little about his machines from this book, but feel it could have been so much more. On the other hand, it told me a lot about how German aircraft companies managed to side-step the Treaty of Versailles in regard to aircraft development and their achievements during the period between the wars, so Four Stars, just. Old copies are readily available from places like the Advanced Book Exchange and Amazon Booksellers .
The next new book follows the theme, being titled, Focke-Wulf FW 190 "Long Nose": An Illustrated History of the Fw 190 D Series, by Dietmar Hermann, translated from the German by David Johnston, Schiffer Military History, China, 2003, ISBN 0764318764. This a coffee table hardback with 206 pages containing extensive photographs, drawings, graphs and tables, plus a six page appendix showing color schemes (side profile only). To me, the D model of the Fw 190, and the Ta 152 models which came after them are about the most attractive fighter aircraft of World War II—certainly the most attractive, aggressive looking of the German aircraft of WWII, and perhaps even nudging the P51 Mustang out, as well, if we include the Allied designs. This book was bought so I could learn all I could about the aircraft. It's a bit of a disappointment.
Yes, the history is well researched and well presented. The photographs are generally quite good, and the tables showing comparative performance of "Dora" against Allied aircraft such as the Spitfire Mk XIV, P51 D Mustang, and Mk V Hawker Tempest are enlightening. Again, I'm not sure what I was expecting. I've read that the Fw 190 had a single throttle lever that automatically managed engine speed, manifold pressure, and mixture, which worked perfectly and which its pilots loved. Having jiggled my share of these three levers in large light aircraft, I'd love to know how this worked, but it gets no mention. Other sources make mention of the many advanced features of the aircraft which were actuated by electric motors (the RLM having issued a directive to use electric motors instead of hydraulic systems), but how Kurt Tank replaced several with hydraulic systems in the D model. Again, no mention. Are the "other sources" wrong, or did the author consider this unimportant?
I guess I was after a level of technical information which is of no interest to the readership of books like this. If the contents are a guide, they want to know what units were equipped with what models, on what date, and who flew them. This book has that information, although it is not overburdened with it, as some others are. It does extensively cover all the versions and prototypes of the "Long Nose", including the fate of the prototypes, where known. I would also have liked to know what the stenciling on various parts of the aircraft meant, such as the "calibration" marks on the undercarriage leg doors, and the strange colored triangles that appear at odd places on the fuselage. I gather that some near the canopy track may be to warn of the shotgun cartridges used to blow the hood into the slipstream to jettison it quickly in an emergency, but that does not explain the others.
The coverage of the Junkers Jumo 213, and Daimler Benz DB 603 inverted V 12 engines is rather sparse too, especially as it was the shape of these which caused the nose (and tail) to grow for the D model of the Fw 190, and the Ta 152. We get indications of the rated and war emergency power developed (with water-methanol (WM) boost in some cases), and a little about the associated superchargers, but again, the treatment was not what I was expecting. Overall, the book was a bit of a disappointment, although the effort the author has taken in his research is evident, and I did pick up a few things I didn't know which were interesting (and a lot which weren't). So three and a half stars; copies available from Amazon .
Last, we have a big disappointment, bought after reading customer reviews on Amazon, a practice I will now have to temper with experience and better understanding of where some of these reviewers may be coming from. The book is, Focke-Wulf Ta 152: The Story of the Luftwaffe's Late-War, High-Altitude Fighter, by Dietmar Hernam (again), translated by David Johnston (again), Schiffer Publishing Ltd, China, 1999, ISBN 0764308602. Another coffee table item with 144 pages, illustrated with black and white photos, drawings, tables, and graphs, as as with the other Schiffer book reviewed above, a table of contents, but no index.
What a disappointment. A book about the design which appeals to me so much, that says so little, and does that badly. Sadly, I ordered this and the other Hermann title together, based on all the five star rankings on Amazon. If I'd bought just one, I'd probably never have touched the other. That said, the book on the Fw 190 D is not awful. This one is, needing if nothing else, an editor. I found the same paragraph repeated identically in three locations through the book. I guess we can excuse the translator, although he must have spotted it, but what was the author thinking, and how did the editor let him get away with it? It smells of pure money grabbing to me.
This book is supposed to be the definitive work on the ultimate development of the Fw 190, reissued with the designation Ta 152 by the RLM in recognition of its designer (Kurt Tank), rather than the company which designed it (Focke-Wulf). Maybe there's just not much to know about this aircraft, so the author padded it out by repetition. There were two basic models, the Ta 152 A, B, and C, and Ta 152 H, the latter being a very high aspect ratio design intended as a high-altitude fighter interceptor. This had a wingspan of 14.4m, as opposed to 11.0m for the other models. On January 20, 1945, Oberfeldwebel Freidrich Schnier flew a Ta 152 H to 13,654 meters (44,796 feet). The H model was fitted with a pressurized cockpit, but the bladder system intended to seal the canopy was unreliable. Obfw Schnier's test report is quoted in the first person where he recounts how, due to the poor pressurization, he became itchy and experienced pain in the elbows and knees above 10,000 meters. As he climbed, his field of vision narrowed and his since his right arm no longer obeyed his will, he continued with his left hand! Some time later, he experienced further difficulties (unstated, but must have been doozies) and decided to head back. That is what I call one dedicated pilot!
Unlike the Hermann book on Dora, this one at least contains some illustrations of the cockpit layout. It also contains some photos and illustrations repeated in the Fw 190 D book, such as a photo of the DB 603E engine, and a fairing on a prototype equipped with an oblique reconnaissance camera, fitted to Fw 190 D with the code TR+SB. The photo is "justified" in the Ta book saying such an installation was planned for the Ta 152 E-1/R1 series. As this book was published before the Long-Nose one, the re-use is on the other foot, not that it matters.
Again, the book is short on technical detail, and long on model numbers and their dispersal, plus the test pilots involved in the development of the aircraft. Comparatively small numbers of the Ta 152 were built. I'm sure I read the number as something like 250 aircraft total for all types, but could not find the number again for this review. I did locate a statement that 15,000 were to have been produced by March 1946, and that curiously all of the blueprints for the Ta 152 were sold to Japan in April 1945, however no production was undertaken there. So a big disappointment, saved only marginally by the cockpit detail and some of the (factory) illustrations of subsystems. The best I can give, and I'm probably being generous, is three stars. My copy was bought at full proce from Amazon .
Engine Of The Month: H&R Rattler
How does he do it?! This month, Adrian Duncan continues on his crusade to investigate and document every big bore speed engine ever to receive some acclaim in the circles of old, be they land, sea, or air. this I know from having to create these introductions on a seemingly never ending basis! This month's is (again) something rather rare and special, the H&R Rattler. Adrian received some very special inside knowledge on this project from Luke Roy, and Bill Husted, the latter via his wife, Kathy, and if you have not twigged yet, "H&R" equals "Husted and Roy", so how much closer to the source can you get than that? Ready? Comfy? Settle back and follow the link, or click the thumbnail to be transported back to the 1960's and the early days of record making control line speed engines, sand casting, the H&R Torque Transfer Unit, and the Class B Speed fliers and models they flew (I love the hand launch photos the boys provided Adrian with for their tribute review ).
Tech Tip of the Month
Some time ago, I wrote a Tech Tip intended to either help new model engineers outfit their workshops with the bare essentials needed to make model engines, or scare them off entirely; one of the two. It is called Kitting Up, Part 1 because I fully intend to address the next step beyond the essentials someday, Real Soon Now. With that in mind, I started scratching my head for inspiration as to what to talk about in this month's tech tip—something to help those just starting out. As scratching felt good, but was otherwise not a lot of use, I leafed through a metal workers' handbook to see if anything would move my mental block and spotted a picture of a DTI (Dial Test Indicator). Ah-ha! Says I to myself, that's it! On checking the Kitting Up piece however, it seems I did mention that as an essential, and still agree with what I wrote regarding which type to get (two, actually—if the budget will support them). Then I thought about the other types I have in my measuring devices drawer, and how little they get used, thinking that perhaps a quick mention of what they are and how little I need them, plus why, might be of interest to some.
First, we have this beautiful piece of top quality American kit, in the fitted wooden box which I find almost irresistible. This is called a "Co-Axial" indicator and is generally used to very precisely pick up the center of some bore (in the shop, not at parties). It could be used in the mill to position the quill precisely over the center of some existing hole, or in the lathe tailstock to position something with a round hole precisely on the lathe axis when clamping it to the faceplate, or in a 4-jaw chuck. It can also be used on the external surface of round stock to pick up the center using the alternate probe tip you see in the box. This tool gets occasional use, but not a lot. With my round column mill, I find that it takes up so much vertical space that after centering, I frequently can't get the quill low enough to touch the work, and with the round column, lowering the mill head looses the registration provided by the co-ax indicator! A dovetail slide mill/drill, or a real Bridgeport style mill would make this tool see far more use, but for me, it has been a less than wise investment.
Next, in Yet Another fitted wooden box (*sigh*), we have a bore gauge. This is a medium quality, Japanese "cheapie", but not all that awful, despite the plastic. As you see, it covers the range 0.36" to 0.76", which should be fine for most model cylinder bores, right? Well this one has seen rather little use too because first, it's more of a comparator than a measuring device. It can be "calibrated" if you have a set of bores, honed to fine precision in respect of diameter and roundness and use them to zero the pointer on a known value. But when I use it, I'm mostly checking the taper of a bore, and/or the circularity. The problem with it is that it is a "two point" bore measuring device. This means it has to be jiggled axially to get an accurate reading—in fact with care, you can make it read almost anything. More expensive types use a "three point" probe, making them far easier to use, and to get accurate, repeatable readings. Of course, this makes the probe larger, so the range may not extend so low. Anyway, call this another tool which has been useful on occasion, but something that should not be on your shopping list if the budget is at all tight; A good set of telescoping "T" gauges, or good quality ball gauges and your Vernier or micrometer is a better solution to measuring bores.
Lastly, in a plastic case, we have this top quality British "Verdict" DTI. I bought this at great expense while building the QUORN tool and cutter grinder because one, count it, ONE step in the alignment procedure showed Professor Chaddock using one and somehow, I decided this was the only way to go. I also think it is the only time I've ever used it! In retrospect, the job could have been done using some of the hardware selected from the Starrett DTI appearing in the heading paragraph of this tip (and in the Kitting Up article). This has to rank at near my most unused purchase, but at least it has been used. Maybe someday, I'll talk about the tools I've bought and never used!
So there, a tip on things I've found to be not as useful as they initially looked to be. The story might be different if I was doing a different class of work, or if I knew what I was doing, for that matter. Still, perhaps this might help you think before quoting a card number and allow you to spread your workshop budget a little more wisely.
An eagle-eyed reader has found a couple of missing dimensions on the cooling muff plan view of our EmBee plan set. Now I know others have built engines from this plan set, so they must have either guessed the OD of the cooling fins, or measured the plans—generally a bad idea, but not a totally despicable act on a non-critical dimension. The plans have been updated with a new sheet 3.
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.
- Maris Dislers has been added to our People Index because he deserves it, plus it makes it easier for me to cross-link to his Taipan book review whenever I need to!
- Aero modelers may like to have a look at Zoe's Control Line Site, which runs the gauntlet from nostalgia to modern Linux hacking (in the old sense of "hacking", when it meant clever people, not bad people).
- Owen Engines (Australia) has a new price list out.