SMALLnet post401

David Felin asked for a repeat of a vendor's address that had appeared in a previous Posting.

This gives me an opportunity to once again point folks at the SMALLnet website. One of the features you will find there is a Source Index.

Whenever Joe (or Randy as the case may be) sends out a Posting, I put the Posting in the Archive at the Web site. In so doing, I annotate the Posting, so that the when someone says "You can get the Furble at Joe Littleplane's shop," the "Furble" shows up in the index, and is a link to the posting where it was discussed.

I looked there, and perhaps I didn't catch the very latest source, but there is one there under "Wings, ACE R/C mini-foam".

I am sure many of you already know about this new virus. The virus grabs random subject lines from the infected system, but ALWAYS adds the "Re:" to the front of them. The other thing that is a dead give-away on this one is the space (really an underscore) as the first character of the e-mail address in the "From:" line.

A VERY IMPORTANT thing to note is that the virus is NOT, repeat: *NOT*, coming to you through the < > e-mail list!

Since the virus picks up a random subject from a message that the infected computer has received and uses it in the e-mail it sends, it may APPEAR that the message is from the list. Since several who have infected computers are on the SMALLnet e-mail list, it is quite likely that they will send the virus using an old subject line from a previous message that DID come through the list.

The many steps that have to be followed before a message gets to you via eskimo.com guarantees that the list will NOT transmit a virus.

The very FIRST of them catches this virus: the modified "From:" line (where the leading underscore has been added) automatically kicks the virus out since the name with the leading underscore is NOT on the eskimo.com subscriber list, and only subscribers can post to our list!

Each time I receive one of these messages (and I have received quite a few), I respond to the originator by first removing the extraneous leading underscore from his e-mail, and then passing on the information on how to recognize and eliminate the virus.

...Chris Murphy < > had his computer infected by a virus, which sent three spurious e-mails to SMALLnet. But my server blocked the evil content. I had my system scoured out anyway by McAfee (they provide an on-line service) and it's clean. [JW]

Greeting from Oz. Re those virus attacks: they are bloody annoying. I have found one that constantly keeps popping up but is easily detected if you know how -- and here it is:

Firstly the Virus is "WORM-BADTRANS.B". It shows up as an attachment with zero bytes in it. I always open any attachment rather than save to disc, as this isolates the information in one part of the computer. When you try to open it, it won't; when you try to use the "reply" function to sender; that won't work either.

If that happens, check your address book, and you should find a duplicate of the sender's address (if they are known to you) -- but in any case the address will have a lower case bar at the start of the address. My advice here is kill it then and there.

My virus protectors quarantine these nasties so I can look at them, perverse curiosity I suppose.

P.S. Can someone tell me how to stop people borrowing my discs with all my saved "SMALLnet" sendings? TC

...Trevor, tell them that they can buy a CD-ROM from me ($23 to Australian addresses, airmail postpaid) which includes 392 Postings plus over a dozen SMALL-related articles -- and full instructions for fast and easy searching to locate any and all mentions anywhere in the Postings of a given topic, source, or contributor. My mailing address is: Joe Wagner, 927 Pine Avenue, Ozark, Alabama 36360. [JW]

Does anyone have any experience with the Hobbico Sky Sailer Rogallo ARF? My father is looking for something simple and easy with which to cruise the back yard. The little thing looks cute, but I'd love to hear someone's experience prior to his plonking down 100 bucks.

Flying weather has been downright impressive for this time of year here in southern Missouri!

Opened one up and it contains eight sub-C size ni-cds marked SC1300 mAh by Hunghy (made in China) -- not the hoped for Sanyo. The cells have solder tabs and are made up in a "rolled-up" configuration to fit the usual drill battery case, but could be separated and made into any desired configuration. The charger used with the drill is marked as 12V at 500 mAh.

I have recently purchased three old kits from eBay. All three appear to be complete, except *none* of them included the plans.

I would appreciate it if any of you can loan (for me to copy) or make copies of the plans for me. Please contact me: Trent Eyler; 1906 East 13th Street; Tulsa, OK 74104-4422 (918) 592-0517 or by e-mail.

1. Black Bullet 40" from Schlueter Free Flight models (BB-40) 40" span (I assume)

2. Cavalier from Micro Models "for sport FF or single-channel R/C" (F104) 36" span

3. PUP II from RN Models "Free Flight low wing sport -- suitable for small R/C .020 power" (UA412) 35" span

To answer Ed Stevens, I would buy an .03 that throttled well and would swing a 6 x 3 prop if priced around $55. I like my little diesels, but my PAW .033 weighs the same as a Norvel .061.

A lighter engine would fill a vacant niche. For me, it would have to be pleasant to use -- easy to start by hand, steady running, with a reliable idle and transition. There is so much new light- weight gear coming out for electric park fliers, but we "wet" engine enthusiasts can't take full advantage of it without a lighter engine. Even an after-market exhaust sleeve for the C*x .020 would be a big help.

Another note to manufacturers out there -- how about some small spinners and new shapes? There seems to be a conspiracy to make spinners no smaller than 1 inch diameter, and all in the same style. But 1 ½ inch spinners are too big for many of our small models, and Wacos, TravelAires, Spitfires, Hurricanes, Pitts Specials, Piper Tri-Pacers, Cherokees and Super Cruisers, and other popular scale subjects need spinners shorter for their diameter than anything on the market.

Ace advertises some of their planes with spinners they no longer make, and Herr doesn't show spinners on some planes that should have them. Currently-available spinners would stick out like a sore nose. Even on some of the common sport types it would be refreshing to see something different. Obviously the economics depend on volume of sales, but if someone produced spinner sizes and styles that no one else did, I think they could have a "designer line" at a premium price and still get enough takers. Or am I the only one who thinks so? Jim Rundle

I was wondering if there are any SMALLsters familiar with Rhoe Apt's Puddle Jumper. I've been building mine from the plans in the May 2001 issue of Flying Models and have it ready to cover. Man, it looks big for an OS .10 at 800 square inches!

I've been trying to keep it light as possible, and it tips the scales at 23 ounces, less radio and covering. I should be close to the prototypes' 41.6 ounce total. I guess there's no harm in size, as long as the weight is low, and there's lots of lift.

I'd sure like to hear about anyone else's experience with this unique design. Allan Leppanen

Converted a Funcraft foam rubberband power to electric R/C. 14" wingspan, 3.2 ounces RTF. GWS IPS direct drive motor on a U-80 prop. Reinforced the wings with Depron. Aileron torque rods are direct-connected to the servo arm.

Wrapped transformer wire around a 1/64 ply stick for the antenna. More data on my web page under "secret projects"

I have read many articles, including yours, on home-brew diesel fuel. Once I showed up at the field having forgotten to bring any diesel fuel. I figured that "Nobody" would have Diesel fuel, but lo and behold, I met DCRC's "other" diesel guy. He loaned me a couple of tankfuls of his home brew (don't know the mix).

My PAW .15 ran OK but it needed approximately an 1/8 turn extra compression. I have been using John Deere 80% ether starting fluid to pep up fuel that seems flat -- but have never made my own diesel fuel from scratch.

A couple of questions. Can I use a kerosene substitute called "Clear Lite" which is made by Gulf ? Is it just extra-pure kerosene, or something else?

If heat is the enemy of oil and diesels tend to run cooler than glow; why not use synthetic? I recently purchased a MP Jet .061 from Carlson Imports. The instructions recommend 40% oil, 40% ether and 20% kerosene. To match this I will have to mix my own. Would my existing PAW BB fuel be OK? Francis S. Person

...Francis, I don't know what Gulf "Clear Lite" is, and there are no Gulf gas stations anywhere near here. The only "extra pure" kerosene that I know about is aviation jet fuel.

The "extra purity" of jet fuel consists primarily of its low moisture content. (Yes, kerosene does absorb water.)

The reason that this is important in full-scale aviation is that the ambient air temperature is so low at the altitudes in which jets normally cruise, kerosene with water in it can turn into slush & overload the fuel pumps.

Plain old gas station kerosene (NOT truck diesel fuel!) works fine in model diesels. People all over the world have been using it for that purpose since 1945. Small amounts of moisture in kerosene don't seem to matter much insofar as model diesel engine operation is involved.

I tried some experiments in this line about 6 years ago. Starting & running adjustments changed a little with my purposely "moisturized" fuel -- but not enough to bother me.

Now for the castor oil question. NO model diesel engine maker recommends anything but castor oil for lubricant. I must have written this topic up more than a hundred times: in magazine articles, replies to readers, and in SMALLnet:

Castor oil is the ONLY -- UNIQUE -- commonly-available lubricant which becomes MORE viscous with heat. And the place that this extra viscosity ("film strength" is another way of expressing that) is vitally needed is NOT between the piston and sleeve, but at the wrist pin.

The wrist pin area is CRITICAL in all model engines, because every erg of mechanical energy that the burning fuel transmits to the piston has to be transferred via the wrist pin. It's the most heavily-loaded part of the engine -- and almost the hottest, because of its location so close under the piston crown.

Yet the lubrication the wrist pin receives is almost accidental. There's no "free flowing" fuel/air mixture within the piston's "underside cup". And an oscillating bearing is the hardest kind to keep lubricated. Unlike rotary bearings, where lubricating films tend to remain in place and renew themselves, oscillating bearings squeeze their lubricant out.

It's to protect the wrist pin & con rod "little end" bearing that Cox has always specified strictly castor-lubricated glow fuel for their engines -- the Cox ball-and-socket connection between piston & con rod becoming exceptionally highly-stressed and hot at typical 1/2A rpm.

Diesels have it worse. Mechanical pressure stresses are usually higher than with glows, especially while starting. And diesel combustion temperatures (especially when running "maximum lean" for best throttle response) are hotter than in most glows.

Believe me, Francis, NO company that manufactures model diesel engines owns castor oil processors. The reason they call for castor oil -- and lots of it -- is that CASTOR OIL WORKS.

I've had letters from modelers all over the world in the 15 years that I've been writing model engine columns, claiming remarkable results in their motors from the use of "NEW" and "IMPROVED" oils of various sorts. Turbine oil; peanut oil; reclaimed deep-fry oil from McDonalds; Teflon-augmented oil; gun oil...

I say, "Yeah, yeah," -- because these guys might just as well learn the expensive way (which will help them remember) that there's a REASON why castor oil has always been standard in model diesel fuel.

And that reason is NOT that fuel engineers are too timid or ignorant to want to try anything else.

To me, searching for a substitute for castor oil in model fuel is akin to trying to find a cheap, efficient substitute for water.

Your "existing BB diesel fuel" has about 20% castor oil. The MP Jets people don't think that's enough to be safe for breaking in their engines. I believe them. [JW]

On the recommendation of a friend, I am planning to build a Terrier (RCM March, 1984 plan 909). This a 58" span aerobatic low wing plane, designed to be built light and powered by a sport .25 glow. The author used a non-Schnuerle OS .25, although early '80s .40 4-stroke engines also worked well.

I want to use a PAW, but don't know which one. A .19 TBR might be big enough if I keep the weight down to around 3 pounds. The .19 is nice in that it only weighs 6.5 ounces and is SMALL. The next step up in the PAW line is the .29 (at 11.5 ounces) or the .35 (at 11 ounces).

I like to fly sort of slow, but also would like enough power to do large loops and the like. Bruce Stough

...Bruce, I have two models powered by PAW .19 plain bearing engines. One's an R/C biplane with about 400 square inches of WORKING wing area (I no longer use "gross wing area" figures -- those that include the part of the wing that's covered by the fuselage); the other is a control-line stunter, 54" span, 600 square inches, weight about 27 ounces.

Both models fly well. The C/L model will climb straight up (as in wingovers etc.) and the heavier R/C biplane does nice "scale- type" aerobatics. The best PAW .19 props I've found are Graupner 10-inchers; both 4- and 5-inch pitch work nicely. [JW]

One of my 1/2 dozen or so "current" projects is an original 1930's biplane. I've never built a biplane previously because I'm too lazy to build 2 wings, so the Ace was the trump on that excuse:

ACE AS 6073 Tapered chord -- 166.25 square inches; root 5.5 inches; tip 4 inches; span 17.875 inches

ACE AS 6074 Constant chord -- 192.5 square inches; root 5.5 inches; tip 5.5 inches; span 17.875 inches

Our local guys are showing a lot of interest in Ace Simple Series after seeing my Simple Corsair fly. It does GREAT with a Norvel .074. I put a 4-ounce slimline Hayes tank in it, as that fit the space nicely.

This plane is fully aerobatic, flies over 20 minutes, and lands with plenty of fuel left! We found that the Me109 makes a good P-40 Warhawk with the addition of a shark's mouth, and a taller rudder will further enhance the effect.

Built the Texan; next is a Hollywood Zero conversion; painted olive drab green/gray with red meatballs! Kinda puts the fun back into WW2 combat.

As most SMALLsters know, the Ace Simple Series kits were designed by the late, great Fred Reese. He really knew his stuff!

Got a Whizard in stock a few days ago. I was surprised to see it is a taildragger, as I always remembered it as trike with pants on the mains. If anything it looks even better as a taildragger.

Thanks again for the great information. Here I thought Campbell, Blue Ridge, and Golden Age kits were nowhere to be found, but it looks like they're distributed in several places. Very helpful, and I appreciate the broad response.

Thanks to JW for writing back about your experience with Cox Pee Wees and props. I'll let you know how it goes when it comes. Pee Wees definitely do make a tiny mess. I was even thinking recently of building a small drainage hole on the underside of the cowl of a Fairchild 24, to prevent reservoirs of fuel from accumulating there.

So far I've built four or five planes, and recently decided to make a small powered micro R/C plane (not a lot of space in NYC, you know..). The hardware and breadth of choices in electric is so wide, I decided to go Pee Wee to simplify things. One thing at a time. Once I get basic construction and flying down, electric will be next. So I built a Guillow Fairchild 24 for two channels, and Pee Wee power. It shot up to about 20 feet at like 60 degrees, then stalled and plummeted.

The Nieuport is next. Joyfully, I notice each plane is successively much better than the last. This time, my transmitter is adjusted for lower sensitivity, plane is lighter, balance is better, throws are smaller, control rod play is eliminated, etc. Any general tips to make this work?

I was really glad to see your discussion of props. As you pointed out, the plans call for a 4.5x2 which barely clears the cowl. I have a nylon and carbon fiber Grish 5.5x3, and I am hoping one will work out. I had no idea you could put a 7" prop on a Pee Wee and use it to fly a 46" wingspan plane. Did you use special gearing to get this to work? Would you expect that size to do the job?

One question on a Guillow Nieuport R/C conversion with Pee Wee. Can this take off from the ground? Thanks, Sean

...Sean, I've seen two R/C conversions of the Guillow Nieuport 11. They flew nicely, but had to be hand-launched: they ground-looped viciously on attempted takeoffs.

I used essentially stock ORIGINAL-VINTAGE Cox Pee Wees on my models, modified only by replacing the paltry little fuel filler nipples on the tank back with screwed-in 3/32" hard-copper-tubing forward-facing vents.

The 7" props I use are old, WAY out-of-production Grish 7-2 Plasticote. They run great on Pee Wees -- developing THRUST rather than maximum screech.

For the benefit of other SMALLsters with Pee Wee powered projects in mind, here's a condensed collection of Pee Wee information taken from my recent e-mail replies to Sean and other "interested parties":

> Your difficult Pee Wee starting problems are probably due to
oxidized castor oil gumming up one or two critical areas inside the Pee Wee. This is COMMON on engines that have been stored away a while.

The critical areas are the reed seat and the fuel orifice. These have always been problems in Cox reed valve engines. Cox tried a couple of "preventive measures" to alleviate these -- one was a Teflon reed, but that didn't work well in operation for long.

"Castor adhesion" remains troublesome for those who don't know what's gone amiss inside their little power plants.

Solvent or raw fuel will usually do the job -- the problem is getting it in to where it will do some good. If the fuel orifice is blocked, that prevents fuel from passing through to rinse it clean. And if the reed is stuck, even partially, to its seat, that makes the oxidized area hard for solvents to reach...

I take my Pee Wees apart every once in a while & clean their insides manually. I also replace the plastic fuel tubing, which has invariably lost its flexibility -- and MAY even have a tiny air leak where it fits over the nipple.

Gasket leakage can give Pee Wee owners a tough time too -- especially the little TEENY one between the tank back and the end of the intake tube.

Now you know why I prefer PAW .03 diesels to Pee Wees. They're SO much less finicky to keep running! (Also, have you checked the price of a Pee Wee glow head recently??????)

One more possible source of Cox starting trouble is the glow clip. If you are using a stock Cox "bifurcated clip", modify it before flipping one more prop! That design is the absolute VILEST excuse for a glow plug connector that I've ever seen.

Remember that the plug needs lots of current to light brightly -- a couple of amps usually. (I forget what the .020 glow head draws and am too lazy to go out to the shop right now to check.)

Anyway, here's how to fix the Cox glow clip so that it will be capable of delivering amperes worth of current.

Along one side of the yellow plastic "joining sleeve", CAREFULLY cut through. When the sleeve is split on one side, it can be spread apart and the metal connectors can be pulled out. (These have small barbs on them: be careful not to ruin anything.)

Now remove the stock wires from the metal connectors and discard them. They are 24-karat JUNK. Instead, get a couple of feet of thin-gage lamp cord (14 or 16 gage is fine) and SOLDER this to the metal thingies (scraped clean first!) where the old "pushed-in-place" stock wires were.

Now put everything back together -- and use shrink tubing to repair the split in the yellow plastic sleeve.

NOW your Cox glow heads will LIGHT.

> The Pee Wee appears compact & simple. It really IS compact --
but the simplicity is illusory. The operating principles and actions are no less complex than on larger model engines; and additional difficulties arise because of "scale" effects.

Two detrimental "scale effects" in all miniature model engines are:

1. The smaller the displacement, the higher the ratio between cooling surface area and combustion chamber volume. That causes small-sized engines to run cooler. That in turn makes it more difficult keeping the combustion process going, in both glow and diesel model engines.

2. The physical dimensions of model engines can be scaled up and down readily enough. However, the properties of the "fluids" they operate with: fuel and air -- remain constant. They don't flow so freely through small passageways... (That's one reason it's poor practice to use tiny fuel tubing on small model engines. That just makes it harder for the engine to draw fuel.)

It's quite easy to design & manufacture a good-running & depend- able .15-size glow or diesel; but FAR more difficult to produce an .015 with those qualities.

One more "hidden complexity" in Pee Wee operation is common to all the Cox reed-valve engines with built-on fuel tanks. That's the varying fuel level in the tank. A full tank has its fuel level above that of the needle orifice. Fuel then "gravity-flows".

If you adjust the needle on a fully-fueled Pee Wee for maximum rpm, its mixture will become leaner and leaner the longer it runs. This will probably cause the engine to lose noticeable power in flight; and often to stop prematurely.

To sum up: the Pee Wee is a neat-looking little power producer -- but it has its quirks...

And run it -- and all other Coxes -- ONLY on all-castor-oil lubricated fuel! (I use Byron's 25% nitro, all-castor fuel, with 5 fluid ounces of castor oil added to each quart. Cox engines NEED lots of castor oil!)

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SMALLnet Posting post401