SMALLnet post380

...Back again, gang -- with a couple of announcements to make before getting to the submissions.

First, I'll soon be moving SMALLnet's "editorial department" to a new server. Juno worked very well for quite a while for receiving submissions and putting together Postings. But recent changes in Juno's policies have made going to a new server imperative. (For one thing, 80% of the SMALLnet in-box contents is SPAM now.)

This won't affect you in any way, except for those who have been sending in their submissions direct, instead of through Eskimo. And you won't be seeing that irritating Juno ad at the end of the Postings any more!

There will probably be one more Posting from this Juno source. In that I will provide the new SMALLnet e-mail address.

Second, here's more data on the SMALLnet CD. Everyone who has received one has liked it, with one exception -- and he MAY have gotten a defective disk; if so I will replace it.

However, at least one SMALLster didn't realize that this CD is purely a data storage disk. It's like word-processor data stored on a floppy: you need another program to access the CD contents. On the back of the SMALLnet CD's "jewel case" are brief instructions for finding specific topics among the 376 Postings included. Those instructions will activate either WordPad or NotePad (depending on how your Windows "Find" function is set up) for reading the Postings.

But you may find it more convenient to use WordPerfect or some other word-processing program. Whatever: the SMALLnet Postings are all stored in "plaintext", ASCII format, with 70-characters-maximum-per-line, just like this Posting.

I have the pricing now for CD's shipped outside the USA. For Canada the price is $21 (US dollars); for all other countries it's $23 US. The added charge is for postage, duty fees, and my extra trouble in having to fill out the dagnab Customs Declaration forms.

I've been using a copy of this CD myself lately. I've found that it has advantages over the floppy disks that I previously stored my Archives on. The CD is FAST !!! In fact, looking up data (e.g. Speed 400 recommendations) on the SMALLnet CD is considerably quicker than on our web site -- and you don't need to be connected to the Internet to use it. [JW]

Anyone interested in the upcoming PopGun SMALL event at San Antonio, please visit our web site and look at the schedule of events -- or go directly to: < http://propbusters.org/flyer_gif.GIF > to see the flyer.

I'm trying to find model plans or 3-views of a General Aircraft Monospar. Can anyone help?? THANKS

...David, there were quite a few different versions of the Monospar made between 1931 and 1938. All were twin-engined; but some had fixed landing gear; some retractable. Most had single vertical tails, but a few had twin rudders. The first ST-3 model looked rather bulky, but the fuselage was slimmed down considerably on the ST-4 and most of the later models -- which extended to the ST-25 (first made in 1936).

A goodly amount of data, several photographs, and 3-views of the ST-4 -- and ST-25 with twin rudders, can be found in A. J. Jackson's "British Civil Aircraft 1919-59", Volume Two. (Putnam, London 1960) [JW]

I have heard mixed reports about using the Hitec CG335 4-24 cell charger with NiMH cells. Can anybody out there give me some reports based on personal experience?

If no one else has stepped forth yet on this, I have a NIB complete kit of the Comet 54" Taylorcraft in my kit stack, and I would be willing to Xerox the die-cut parts Trent requested. Ain't this list just the handiest thing since CA glue?

I also have built the Comet 54" Aeronca Chief (Mini-Olympus 2.33:1 with a Speed 400 6v motor, 9X4 Zinger, 7 600 mAh Sanyos, Sprite 25 with BEC, 2 HS81 servos, 24 ounces All-Up Weight). It flies great!

I covered it with white Micafilm and a blue pinstripe down the sides, and blue N-numbers. Looks very scale up there, and it thermals well, too.

When I get around to the Taylorcraft, I will be using my Thunder Tiger GP07 engine in it. The OS10 will also work, for a little more weight. You will need to beef up the forward fuselage with a little sheeting. I did this on my Chief, and I also replaced the balsa wing spars with hardwood. The wing panels and struts are permanently glued in place (transport has not been a big problem).

I made a belly hatch for battery access, and a hatch on the top of the cowl for motor access.

These things are large and lightweight, so avoid breezy days and rugged flying sites. And watch where you grab the fuselage!

I just bought a NIB Enya .09 R/C, with muffler, at a swap meet. It is mounted and ready to go in my brand-new Sig Colt. The muffler is a clamp-on type (gasket included), with a butterfly valve that can be swung 90 degrees to the open position. There is no pressure tap.

So, all of you who have played with a muffler like this, should I play with the butterfly valve, or just leave it closed? What's it for? Are you supposed to open it for starting and then close it once the engine is warm, or what? Maybe it is for priming directly into the exhaust opening?

Also, do you recommend that I drill a hole somewhere and tap it for a pressure nipple? Or does this motor not need tank pressure? It's a nice engine, from the looks of it. I've owned several O.S. .10 FSR and O.S. .10 FP motors. How does the Enya compare?

The Sig Colt, incidentally, was a pretty good kit. It fell together when I turned the box upside down, and it seems plenty strong and light. It looks like a cute Cessna. I expect it should fly great on rudder/elevator/throttle.

...Don, the Enya's pivoting "butterfly" was intended to allow priming directly into the exhaust. (I wish other modern engines had that feature!) As for adding a pressure fitting to the muffler, I'd try flying without that -- and see whether muffler pressure is needed for dependable running. The modification is easy enough to make if it turns out to be necessary. [JW]

The Mosquito Squadron of the Ottawa Remote Control Club has updated its winter building project of the "Cassutt racer" with notes on making your Cassutt Electric!!! Frank Reaume was kind enough to pass his notes on, and they are now included in the web page. Since I am not an Electric type guy, if you have questions about it call Frank! < >.

You can still get a Cassutt kit if you want one; see < http://www.ottawarcclub.com > and go to the Small airplanes button for the juicy details

Also let it be known the little busy beaver known as Ken Park has been working hard designing next year's winter project. And Yes, the design is a SECRET!!! We want to be 100% ready long before the snow flies so you can get yours before Christmas!

We got off to a slow start this year and we had many delays from our sources that didn't help. So if you're good, you might see the SECRET prototypes fly at the Mosquito Squadron SMALL fly-in on July 28/29 2001. Ken Park

I just finished building a Sterling Sopwith Camel (24 inch) from an old kit I won on Ebay. I installed a 3-channel radio (Hitec 555 Receiver, HS-50 servos, 110 nicad pack) and a PAW .03 diesel. The finished plane weighs 11.5 ounces and is covered with Japanese tissue, 2 coats of nitrate dope, acrylic paint for color, and polyurethane clear coat.

It flies fine, although I should have enlarged the tail areas by 20% for more stability. This is the fourth conversion to R/C of a Guillow or Sterling rubber kit for me, and the combination of the PAW .03 and a small 3-channel R/C set continues to work very well. Pictures of the model can be seen on the web at:

I encourage more modelers to try the PAW 0.03 on small R/C models. It throttles very well and with an exhaust collector is as quiet as an electric! Steve Morris

I was making up a set of carbon rod pushrods -- found the right length, how to mark the rods? Picked up a Sanford Uni-ball "Gel" pen. It was a bright yellow color (remember, these pens are made to write on black surfaces) and makes a 'bright' yellow mark on the carbon -- problem solved! Ron

Talking about Vic Smeed's small F/F models: another one that I like is his Paageboy (sic), designed for a 1 cc PAA-Load class here in the UK in 1953. My version has an ED Bee and rudder/elevator.

Can't tell you how well it flies -- completed it in November but awful weather, followed by all our local fields being closed due to foot and mouth precautions, means that it is still awaiting its first outing!! Mike

I can answer one of the questions that came up in the recent Postings with regards to the Playmate, since I've still got mine. I'll attest that it flies very well; I've lost count of how many hours are on mine. Unfortunately, the plane is in storage, but if I recall correctly, the weights given in the article were reasonably accurate.

I've powered mine with two motors, an HB 25 (non-schnuerle) and a K&B Sportster 20. The 25 was way too much power -- 3-channel airplanes with lots of inherent stability get pretty squirrely when they are really overpowered. The Sportster 20 is a nice combination, however, since I've been flying this airplane with 4-ounce battery packs (lazy) I'll lay long odds that a plain- bearing .15, and a radio weight of around 6 ounces would do fine.

I'm a little dubious about electric conversions however. The Playmate is a stout design, but with plenty of wing area. Adding lots of weight will alter its marvelous flying characteristics. Alternatively, weight could be stripped out of the airframe, but then it won't be so robust.

I was tickled to read about a Sterling Mambo being electrified. I've got a soft spot in my heart for that airplane, since it was the first airplane that I actually got some significant stick time in a single flight. I've still got a Minnie Mambo kit lying around, but the box is mighty heavy for an electric airplane....

Who can give guidance about the angle (Z-plane) that a pylon- mounted engine should make with the fuselage centerline? The Herr Aquastar has the engine well ahead of the wing and at about zero degrees (by eye). A pusher model ("Lake something") that I have not yet built has the engine located close above the wing TE, and angled upward maybe 15 degrees (from memory).

A speaker at our last club meeting said that some models have downthrust. This seems counterintuitive to me for a pylon-mounted engine. Are there any rules of thumb for choosing the thrust angle of pylon-mounted engines? Ian M

...Ian, there's one general "Rule of Thumb" covering this sort of thing: "If it works, it must be right, even though it may seem to contradict 'established theory' -- and if it DOESN'T work, it must be WRONG, even if it conforms absolutely to 'established theory'." There are simply TOO MANY variables involved in pylon-engined flying boat design for any "recommended thrust angle" formulas. Whatever WORKS is right. [JW]

I have been reading a few Postings regarding the Sig Rascal. I would appreciate any input on its flying characteristics, duration, etc. John Rossetti

Andy Woitowicz asked about buying Marvel Mystery Oil in Canada. Go to Canadian Tire; the product is in the Automotive Section -- a red bottle -- about $3.00 Canadian. Rick

A quick Internet search turned up West Fleet Direct in New Mexico which has a toll-free number for telephone calls from the US and Canada: 877-235-3387. The web site is < http://www.westfleet.com > and e-mail is < >. Dave Segal

I don't know about Marvel Mystery Oil, but over the years I have had very good luck with plain old automatic transmission fluid. No trouble starting, and for long-storage use a coffee can of the stuff, drop in the engine, and forget about it.

I bought a Cox Conquest .15 back when it was new on the market and I had delusions of becoming a contender in FAI. This engine has languished in the box ever since, mostly because of inactivity in FF power and because of the impossibility of obtaining the insert plugs required.

I recently got an R/C head which uses a standard plug, and have plans for finally using the engine.

Use of the R/C head is recommended in the original operating instructions if frequent plug changes are anticipated, i.e. high nitro fuel. Additional gaskets are suggested in this configuration (Cox Part #28180) if high nitro fuel is to be used, or if piston/ head interference is experienced after parts are seated. Are these the same as the insert plug gaskets?

The piston is a squeaky fit at the top of the stroke. Feels a lot like a new ABC engine. Is this correct.?

I would appreciate hearing from people on the list that have had some experience with this engine. BTW I bought an extra insert plug with the engine. It is marked $1.75. Current glow head prices make me thankful that I had the accidental foresight to buy a bunch for my Tee Dees. LeRoy

I have three glow plug engines -- a Cox Pee Wee, an OK Cub 049, and a Testors-McCoy 049. We also have one or two diesel engines of similar size, and I find those tend to be more flexible in terms of power adjustments. The noise levels are also more tolerable.

We fly Free Flight and a bit of control line. I observe at Free Flight meetings that we attend here in the UK, the popularity of reduced-size replica vintage diesels. Some of these tiny-engined models seem to produce little more noise than that of electric power. Glow engines seem to feature quite heavily on SMALLnet Postings -- but perhaps more for radio control work than free flight?

My question is: what is the general opinion on diesel conversions for glow engines? I understand that one is available for the OK Cub. I have also seen a Pee Wee converted to diesel, but was unable to see it in action. I notice dark warnings in the Cox instructions regarding diesel conversion and warranty invalidation etc. Are they trying to tell me something?

Are diesel conversions a practical proposition, or are they a quick way to destroy a good engine? I should be interested to hear from anyone who may be able to advise.

...Mark, in previous Postings the topic of model diesels was covered in great depth. Here's a quick summary to answer the questions you have now.

In general, diesel conversions of designed-for-glow engines are NOT worth the time and expense. True, I have ONE Cox .049 successfully converted to diesel. That uses a variable- compression head from one source; a crankcase and shaft from another source; and the remainder is "stock Cox". But I have also wrecked six Cox .049's in trying to convert them to diesel.

The stock Cox reed-valve shafts are too weak for diesel use. Also, the diesel conversion heads for Cox .020 and .049 sold by Davis use Teflon disks for contrapistons! Those seldom last long -- which is why the conversion kits used to contain about half a dozen disks. (Davis called them diaphragms.)

As for OK Cubs, those were available in 1953-54 as factory- assembled diesels in both .049 and .074 sizes. Those ran well, but diesel power never became popular in the USA, and not many diesel-version Cubs were sold here.

To sum up: there are so many designed-as-diesel model engines available today, there's no advantage whatever in messing with "diesel conversions". [JW]

He has two weights available: the standard (for small light models), and a heavier, stronger version called Clearfilm ES. Go to: < http://www.modelairtech.com > for details.

Although I haven't seen Clear MicaFilm advertised for sale recently, it really is a lightweight, pretty neat covering material. Can't/won't say that it is easy to use, but it is, IMHO, by far the toughest iron-on stuff.

I've used Clear Micafilm on some 1/2A Texaco scale models -- used two ways: painted before application (i.e. spray can paint on the inner/fuzzy side -- you can paint with almost anything, as it won't have to be fuelproof on the inside!) -- and painted after application ('RC' rattlecan paint). In each instance, the material has proven to be quite durable.

Regarding ease of use: On my Clear Micafilm-covered models you can still see imprints of my fingernails on the undersides of wingtips as I tried to pull the stuff tight enough. But, with a bit of heat, the covering bridged over those impressions and they hardly show.

On another model, one that was painted on the outside, you can still see some marks made by rocks from a field that had been plowed/sort-of cleared -- and I know that with tissue or moneycoat, these marks would have been sizeable holes. Again, a heat gun restored the shape after the dents were made. (Yes, a bit of paint would be needed to completely erase the problem.)

BTW: this stuff stays tight over time. In contrast, I have a model covered in moneycoat that spends the summers in a storage locker here in Arizona, where the temperature may get to 130+ degrees easily in there. This model, after a couple of summer/ winter cycles, has gone really saggy and can no longer be flown.

Polyspan (known as Salzer tissue in Europe, available at FAI Model Supply in the US and several other sources) is also quite tough, but application is a bit more difficult unless the model is without compound curves. This stuff has a fuzzy side that can cause some difficulty -- don't dare use it fuzzy side up or you'll quickly be thinking about another hobby!

Unless you're really fond of the 'white' silkspan/tissue look, this stuff needs paint, or at least dye dissolved in clear dope (sprayed on, please).

Both of these materials can produce the joke situation we used to talk about -- crash the model and end up with a plastic bag of parts -- not at all the same as crashing a moneycoat-covered model.

A. A. Lidberg model plan service, Tempe, Arizona; kits/plans catalog at < http://members.aol.com/aalmps > -- and I don't sell either of the above-noted materials.

...Al, I learned a trick last summer about covering with Polyspan. Even "shiny side up", Polyspan gets fuzzy when doped. I tried sanding that off with 400-grit wet-or-dry, which seemed to work. But after the next coat of clear dope the fuzz returned worse than ever.

Vendor: Micro-Mark

Source: Sanding, Micro-Mesh "Soft Touch" abrasive pads

I was mighty worried, but my son David showed me the cure: Micro-Mesh "Soft Touch" abrasive pads. These are available from Micro-Mark < http://www.micromark.com >. They come in a set of six, 2" square soft foam pads with EXCEEDINGLY fine abrasive om both sides. These feel so smooth, it's hard to believe that they have any effect -- but the 2400-grit pad smoothed down every trace of fuzz from my doped Polyspan. And added coats of dope raised no more fuzz! [JW]

Gary Edson wrote about light coverings and the cost of Oracover Lite. Horizon Hobby has Ultracoat Lite by Goldberg for $12.99. Not as many color selections but the same product.

Adding to Gary Edson's interesting and well-researched contribution on lightweight model coverings, we have been manufacturing what I believe is the lightest available iron-on, pigmented covering film.

MicroLite is not very well known, as we are currently only able to produce a few hundred square feet per week; but are working on machinery that will produce it much faster and cheaper.

MicroLite is aimed at lightweight electric or rubber-powered models, with wing loadings under about three ounces per square foot. The greatest weight-saving advantage of MicroLite is that it can be no-wrinkle heat-shrunk on very light framework without noticeable distortion, even on 1/20 inch square balsa framing. Warps are easily removed with a sealing iron.

MicroLite 5 Micron weighs an average of about 0.035 ounces per square foot, compared to the lightest covering that Gary mentioned, lightly-doped Japanese tissue, at 0.060 ounces per square foot.

Having used Japanese tissue quite a bit, I am well acquainted with its propensity to drastically distort a lightweight structure, unless you are exceedingly careful with pre-shrinking, and very tolerant of wrinkles and slackness.

For models with wing loadings of one ounce per square foot or under, we have MicroLite 3 Micron, weighing about 0.023 ounces per square foot.

Clear hinge stock is $4.00 for 3" x 24" sheet. We try to keep all of the colors in stock here for immediate shipment.

MicroLite is used exactly like the common self-adhesive, iron-on plastic coverings in common use, such as Monokote, including heat shrinking after application. Our website (still under construction; hope to get more information and pictures on soon), is < http://ramicrolite.com >. Carl Risteen

SMALLnet Posting post380