Page 1August 2002

August, 2002Vol. 19, No. 8

U.S.A. $3.50

R/C Soaring DigestPage 2

ABOUT RCSD

R/C Soaring Digest (RCSD) is a reader-written monthly publication for the R/C

sailplane enthusiast and has been publishedsince January, 1984. It is dedicated to sharingtechnical and educational information. Allmaterial contributed must be exclusive andoriginal and not infringe upon the copyrightsof others. It is the policy of RCSD to provideaccurate information. Please let us know ofany error that significantly affects themeaning of a story. Because we encouragenew ideas, the content of all articles, modeldesigns, press & news releases, etc., are theopinion of the author and may notnecessarily reflect those of RCSD. Weencourage anyone who wishes to obtainadditional information to contact the author.RCSD was founded by Jim Gray, lecturerand technical consultant.

RCSD should not be considered to endorseany advertised products or messagespertaining hereto. An advertising rate card isavailable for businesses, and clubs.

Feature ColumnistsBill & Bunny Kuhlman (B2),

Lee Murray, Tom Nagel, Mark Nankivil,Dave Register, Steve Savoie, Jerry Slates,

Greg Smith, Gordy Stahl

ArtworkGene Zika is the graphic artist

who designs the unique ZIKA clip art.

RCSD StaffJerry Slates - Editor/Technical EditorJudy Slates - Managing Editor, SubscriptionsLee Murray - RCSD Index/Database

(available on-line)Bill & Bunny Kuhlman - RCSD Web Masters

PayPal Coordinators

Copyright © 2002 R/C Soaring Digest.All rights reserved.

R/C Soaring Digest556 Funston Drive

Santa Rosa, CA 95407phone: (707) 578-7871

e-mail: rcsdigest@aol.comhttp://www.b2streamlines.com/RCSD.html

OTHER GOOD STUFF

19 Classified Ads - New Products 3 Schedule of Special Events

Monthly Feature Photography & Web Version of the Printed Article (where appropriate)Highlights & Mailing Status of the Current IssueAbout RCSD..................................................................................... Subscription Information...................................................Advertising Rate Card (Adobe Acrobat PDF format).............................................RCSD Feature Columnists, Reporters, and Editors....................... (E-mail/web addresses, plus general information about their areas of interest)"Getting Started in RC Soaring" ........ Getting started guide - Adobe Acrobat PDF formatLinks to Organizations, Special Interest Groups & ClubsOn-Line Articles - Great articles originally written for the printed version of RCSD......................................... "Trimming Your Sailplane for Optimum Performance" by Brian Agnew.................................................................................................. "Flys Faster" by Dr. Michael Selig.............................. "The Square-Cube Law and Scaling for RC Sailplanes" by Dr. Michael Selig.................................. "Modifying & Building the MB Raven (Parts 1-4)" by Bill & Bunny Kuhlman............................................................. "Butterfly and Moth Airbrushing Tutorial" by Joedy DruliaBookshelf Listings - A listing of recently published books of interest to aeromodelers.Complete RCSD Index, 1984-2001

RCSD ON THE WEBhttp://www.b2streamlines.com/RCSD.html

TABLE OF CONTENTS

3 "Soaring Site" ....................................................................................... Judy SlatesEditorial ......................................................................................................................... Correction

4 Airbrusing Techniques ........................................................................ Joedy Drulia..........................................................................................Butterfly and Moth Airbrushing Tutorial

16 "Gordy's Travels" .................................................................................. Gordy StahlServicing Servos .........................................................................................Servo Jitters & repairs

17 Ackerman Aircraft18 Aerospace Composite Products18 B2 Streamlines18 Cavazos Sailplane Design18 Hobby Club3 R/C Soaring Digest

Special Interest Groups19 Eastern Soaring League (ESL)19 International Scale Soaring Assoc.19 League of Silent Flight19 Sailplane Homebuilders Association19 T.W.I.T.T.19 Vintage Sailplane Association

Advertiser Index

ZIKA

Page 3August 2002

TheSoaring

Site

Happy Flying!Judy Slates

AN EYE FOR DESIGN

Joedy Drulia, ShenandoahValley, Virginia, holds a

unique design he created: anairbrushed moth, hand launchglider.

This month, Joedy shares histechniques for creating theseunique airbrushing designs,with his Butterfly and MothAirbrushing Tutorial. The tutorialis also available for viewing infull color from the RCSD webpages.

Thanks to Joedy for giving usthe opportunity to share his wellresearched tutorial with sail-plane enthusiasts interested increating their own uniquedesigns!

R/C Soaring Digest556 Funston Drive

Santa Rosa, CA 95407

e-mail: RCSDigest@aol.comhttp://www.b2streamlines.com/RCSD.html

A MONTHLY LOOK INTO THE WORLD OF SAILPLANE ENTHUSIASTS EVERYWHERE

R/C Soaring Digest Subscription Form

R/C Soaring Digest (RCSD) is a reader-written monthly publication for theR/C sailplane enthusiast. Published since 1984, RCSD is dedicated to thesharing of technical and educational information related to R/C soaring.

RCSD encourages new ideas, thereby creating a forum where modelers canexchange concepts and share findings, from theory to practical application.Article topics include design and construction of RC sailplanes, kit reviews,airfoil data, sources of hard to find items, and discussions of various flyingtechniques, to name just a few. Photos and illustrations are always inabundance.

There are RCSD subscribers worldwide.

USA: $30 First Class (CA res., please add $2.25 tax.)Canada & Mexico: $30 AirEurope/U.K.: $45 AirAsia/Africa/Pacific/Middle East: $52 Air

Check or Money Order, only, please. U.S. funds.

Name_________________________________________Address___________________________________________________________________________________________________________________________________

SCHEDULE OF SPECIALEVENTS

February 1-2, 2003Southwest Classic Phoenix, AZ

Please send in yourscheduled 2003 events

as they become available!

Beautiful in full color, allcover photographs are

available for downloading fromthe RCSD main web page.

ZIKA

GONE SOARIN’

Correction

Last month, Tom Nagel discussedhis techniques for converting a

Chrysalis HLG into a Park Flyer. Instep A, on page 8, a fraction was lost insoftware translation. It should be 1/2”.My apology to all of you and to Tomfor the lost fraction!

R/C Soaring DigestPage 4

Introduction

This multi-part tutorial will describeto the readers how to use

airbrushing equipment to createairbrushed butterfly or moth patternsonto vacuum-bagged compositewings. Specifically, the author willdiscuss results of his personal experi-ences and techniques that have led tosuccess and failures in this endeavor.In subsequent articles of this tutorial,the author will discuss the creation of ahand launch airbrush design pattern,airbrushing skills and techniques,issues regarding paint selection, hints,tips and examples of commonairbrushing mistakes. Lastly, theauthor will share with the readerssome additional butterfly and mothdesigns that have yet to be airbrushedonto wings.

Two specific points that the authorwould like to make before the readersconvince themselves that airbrushingis not practical are: first, while al-though airbrushing can be consideredan expensive and costly proposition,the author will endeavor to show howthe average sailplane builder canobtain equipment at reasonable pricesand second, the author (not being aprofessional artist himself) will at-tempt to describe and explain howonly average creative skills are neces-sary to create attractive butterfly andmoth patterns.

Explaining the specifics of vacuumbagging composite hand launch wingsis beyond the scope of this article. Itwill be assumed that the readers arefamiliar with the general concepts ofthe steps involved in producingvacuum-bagged composite wings orhave successfully performed vacuumbagging in the past.

History

Iwas inspired to create a butterflydesign of my own after seeing a

photograph of a Monarch butterfly

pattern that had been painted on ahand launch glider (HLG) wing. DonStackhouse created this pattern on oneof the Monarch HLGs that wereformerly produced by DJ Aerotech(http://www.djaerotech.com). Donposted a reply to Antonio Martinez’sinquiry on the DJ Aerotech web siteexplaining how this design patternwas created. Don also provided weblinks in his reply that directs thereaders to an on-line photograph of hisMonarch design. Don explained thathe used a combination of spraypainting, permanent black markerpens, and brushed on white paint. Healso explained a way to use water-based tints in clear Varathane to colorthe wing while sealing the balsa skinsheeting. The method is perfectlyacceptable for balsa sheeted foamwings, but will not work with vacuum-bagged composite wings.

I began to consider the idea of using anairbrush to paint a pattern onto thewaxed hand launch wing mylarsbefore bagging. The airbrush designthat would be painted onto the mylarswould then be transferred to thefiberglass skins during the baggingprocess. Before this time, I had success-fully used spray cans to paint themylars before bagging, but this did notallow me to adjust the spray patternnor did it allow me the fine controlthat would be needed to paint intricatedesigns.

The first resource that I used to gatherinformation concerning myairbrushing questions was at my locallibrary. To my good luck and fortune, Idiscovered one of the best sources ofinformation concerning airbrushing ina small book called, “Painting andFinishing Scale Models” by PaulBoyer (Kalmbach Books ISBN 0-89024-108-2, http://db.kalmbach.com/catalog/catalog.html or 1-800-533-6644). This seventy-two page bookcontains many detailed chaptersdealing with types of airbrushingpaints, airbrush handles, airbrushingpumps, airbrushing techniques andexplanations of the technical skillsneeded for good airbrushing results.Mr. Boyer also gives many first handperspectives and narratives describingmistakes, accidental discoveries andpersonal opinions regarding airbrushpainting. Although the book primarilydeals with painting static models, thetechniques and methods that areexplained in the book are readilyapplied to painting other surfaces suchas composite bagged wing mylars.

Another good source of information isthe Internet. There are vast amounts ofinformation already posted on variousweb pages that the interested readercould reference for equipment recom-mendations, guides for improvingairbrushing skills and advertisementsfor used airbrushing equipmentoffered for sale.

Butterfly and Moth Airbrushing Tutorial

(Available for viewing in full colorat http://www.b2streamlines.com/

RCSD.html)

by Joedy Drulia© 2002

Page 5August 2002

It would be noteworthy to reveal to thereaders that during this stage of mydesire to use an airbrush to paint abutterfly pattern onto a hand launchwing I had never attempted toairbrush before. However, after doinga little background research andreading, I was confident that it wouldnot be difficult.

I was correct in my assumption.

Equipment

During my initial foray and searchfor airbrushing equipment, I was

led to believe that airbrushing wouldbe beyond my budget constraints. As Ibegan to shop around for anairbrushing system, I became repeat-edly disappointed to discover thatmost of the basic kits from the popularbrand names began at prices in excessof one hundred dollars. However asluck would have it, I accidentallystumbled upon an airbrushing set at alocal Wal-Mart while shopping withmy wife one evening. By this time Ihad almost given up on finding areasonably priced basic airbrushingsystem. The set that I found is pro-duced by Testors, Inc. (http://www.testors.com) and is marketedunder their “Aztec” product line. Thissystem costs about forty dollarsdepending on the package option thatthe user elects to purchase. If thereader is interested, they can locate thispackage on the Testors web site underthe topic, “Airbrushing Sets forPlastic Models.” The model partnumber is 9174. (See photo 1.) Thepackage that I purchased containedseveral bottles of water-based acrylicpaints in various colors, a small can ofcompressed air propellant, theairbrush handle and a storage tray tocontain the paints and airbrush on theworkbench. It also contained a stan-dard black-colored nozzle that needssome explanation of airbrush technol-ogy before moving along with thetutorial.

The concept behind airbrushing is thatcompressed air and paint are mixedtogether in a mist and then the mixtureis propelled to the surface beingpainted. There are two basic airbrushtypes that one can purchase: singlestage airbrushes and dual stageairbrushes. These are also sometimesreferred to as single action and doubleaction airbrushes.

Single stage or actionairbrushes mix a set amount ofpaint with a set amount of air.Spray paint cans operate likesingle stage airbrushes. Whenthe user presses the nozzledown on a can of spray paint,a set amount of paint willdisperse with set pattern. Theuser is unable to vary theamount of paint except byeither moving the spray cancloser or further away fromthe object being painted(which we will later learn inthe tutorial is a bad techniqueto acquire for airbrushing).

surface. The beauty and skill ofairbrushing revolves around thissimple combination move. Somesituations require a lot of paint dis-persal with large amounts of airpressure such as when covering largesolid colored areas of the wing mylars.At other times, the user will desire thindelicate lines and will reduce thevolume of air and paint to in order toallow extra time and control to paintthese lines. Experience is the bestteacher and the more you airbrush, thebetter you will become. One nicebenefit of the learning experience withairbrushing is that the user can elect touse water while practicing on shippingpaper or on paper towels. Once thewater dries, the user can use the samematerial to continue practicing on. Thisis what I did when learning how tocontrol the airbrush spray pattern.

There is also one more choice that theuser will need to be prepared to makebefore committing to purchasing anairbrushing system. It concernswhether the paint is mixed with theforced air internally or externally ofthe airbrush body.

With an internally mixed system, thecompressed air and paint are mixed ininside of the nozzle. Most dual stage oraction airbrushes are internally mixed.The benefit from this is that theairbrush will give the user a verycontrolled paint and air mixture andwill provide consistent spray patterns.An internal system will allow the paintmolecules to break apart (atomize) intovery small particles and thus, willprovide a consistent and reliable air topaint ratio. The major drawback to aninternal system is that the user mustoften disassemble the nozzle and clean

Photo 1Single stage airbrushes are rather easyto operate. Once they are set up, theuser need only to depress a singletrigger in a downward motion and thepaint will spray from the nozzle in apattern that does not vary in width ordensity.

Dual stage or action airbrushes can notonly control the amount of air thatexits the nozzle, but they are also ableto adjust the amount of paint thatflows from the nozzle. This allows theuser to paint thin lines with little airpressure or spread the spray patternwide and cover large areas withgreater air pressure. This type ofairbrush allows the user to disperse athick coating of paint or a light mistcoating in any wide or thin pattern thatthey desire. The trigger on a dual stageairbrush moves in two directions, butwhile it is at rest, it faces furthest awayfrom the user in a vertically top-upposition. Most dual stage airbrusheswill have springs in the trigger thatforces the trigger to remain in thisposition when at rest. At this position,no air or paint will flow from thenozzle tip. By gradually pressing thetrigger down, the volume of air exitingthe nozzle will increase. Once the userhas depressed the trigger down andthereby adjusted the desired amountof air pressure leaving the nozzle,while still maintaining the amount ofdownward force on the trigger, theuser then gently pulls the triggertoward them. As they do this, thevolume of paint released from thenozzle tip will progressively increase.If the user chooses to press the triggerall the way down to cause a largeamount of air to exit the nozzle tip andthen also pull the trigger towardsthem, the spray pattern will be largeand will quickly build up paint on the

R/C Soaring DigestPage 6

out the paint after use or during anairbrushing session when it is neces-sary to change colors.

With an externally mixed system, thepaint does not enter into the airbrushnozzle, but is mixed outside of theairbrush. Generally, the paint is forcedup to the edge of the compressed airexiting the nozzle tip by a combinationof capillary action and Bernoulli’sprinciple. The compressed air, which issituated close to the top of the tube towhere the paint flows, simply pluckssmall particles of paint and propelsthem to the painting surface. With anexternally mixed system, it is some-times difficult to get consistent results.When paints have not been properlythinned, the particles often vary visiblyin size as they land on the paintedsurface since a thickly mixed paintdoes not readily and consistently breakinto small particles. If the paint is toothin, the user will either be forced topaint multiple coats in order to pro-duce the proper paint coverage or riskpaint runs across the surface beingpainted if the paint mixture is too thin.However, one of the most convenientbenefits of the externally mixed systemis that clean up is very easy. Sincethere are no small nozzles to clean ordisassemble, the user can readilychange colors between coats withoutdelays associated with cleaning andreadying the equipment. Many exter-nally mixed airbrushing systems willallow the user to store unused paintsin their own separate containers andsimply cap them closed when notbeing used. To change colors with thistype of airbrush, the user simplyremoves the current paint bottle andreplaces it with another paint bottlecontaining a different color.

Once I gained some experienceairbrushing, I later purchased anexternally mixed system as well. Attimes, I only desired a one-coloredsurface on the wing such as a solidcolor on the bottom of the wing. Ifound that the external system allowedme to work much faster on my openclass sized wings. Once I discoveredthe proper mixing ratios to use forthinning the paints, I learned that Icould obtain rather consistent spraypatterns and air to paint ratios. Theexternal system that I purchased is alsomade by Testors, Inc. and was alsopurchased at Wal-Mart for abouttwenty dollars. The interested reader

can view this system on Testors, Inc.web site under the topic, “AirbrushingSets for Plastic Models.” The modelpart number for this externally mixedairbrush system is 8821. Thisairbrushing package contained onepropellant can, the airbrush handle,and several empty paint bottles. It isbest suited only for broad coverageapplications and is not that suitable forfine, detailed airbrushing. However, ifthe user experiments with the settingsas well as the air to paint mixture, thissystem is able to spray moderately finelines of static width and thickness. Thereader is forewarned that producingfine lines with this particular system ismuch more challenging than with adual action airbrush.

Although I have not used the Badgeror Pasche airbrushes for comparisonpurposes, I will recommend the dualstage/action Aztec system by Testors.This system has a few advantages overother systems. The first has alreadybeen mentioned and it is cost. Foroccasional airbrushing, I have found itto be a good value for the money. TheAztec systems are made out of plasticinstead of metal, but I have found it tobe of adequate quality. For cleaning,the dual action Aztec systems offer aninnovative screw in nozzle thatdisassembles into two pieces. Thismakes it very easy to clean. Testorsalso sells interchangeable nozzles suchas one for very small lines, one forbroad coverage and even one forstippling paint patterns. The nozzlesfurther assist the user by limiting theamount of paint released (such as withthe fine nozzle which will prevent overspraying and surplus paint sags andruns). There are about eight differentnozzles that you can use and they arecolored differently for easy identifica-tion. I have found that the blackcolored general-purpose nozzle willhandle just about all of my needs. I didpurchase a large coverage nozzle(white colored) and a stipple coveragenozzle (pink colored). To clean thenozzles, the user simply separates theinternal pin unit from the outer shell ofthe nozzle by gently pulling it apartand then soaking the two pieces inwater or airbrush cleaner. Using paintthinner or mineral spirits is onlynecessary if the user elects to use oil-based paints. Occasionally, I will havea small amount of dried paint left inthe nozzle that will impede theairbrush flow, but it is easily removed

by running compressed air through thenozzle or by using a small pick toremove it. The different nozzles areabout ten dollars each, which isreasonable in my opinion. The Aztecsystems will allow the user to useeither water-based or oil-based paints,although the user will need to pur-chase the specific oil-based nozzles ifelecting to use this type of paint. Thesenozzles cost about ten dollars each aswell.

Both the single stage and double stageTestors systems can use portablecompressed air cans. These look liketypical spray cans, but without thetrigger nozzle on top. (See photo 2.)

Photo 2

Replacement propellant cans usuallysell for about five to seven dollars. Theend of the airbrush hose screws intothe can to provide compressed air. Asthe air is expelled from the can, andespecially during long periods of use,the can will become cold and this willnoticeably reduce the amount ofpressure coming from the propellantcan. One way around this as suggestedby the instructions that come with theairbrush system is to place the can intoa bowl of warm water duringairbrushing which will help to preventthe propellant can from becoming toocool and will somewhat maintain theamount of air pressure. What I discov-ered was that I sometimes needed atleast two cans just to paint the top andbottom mylars and sometimes a thirdcan was needed if I was doing veryintricate work. Generally, you can

Page 7August 2002

expect a propellant can to last aboutthirty minutes.

To minimize the amount of cans andthe constant trips to purchase them, Idecided to purchase an air compressor.The model that I purchased was abasic model made by Pasche. (Seephoto 3.)

cases, can be thinned with water aswell. They do not have strong objec-tionable fumes or odors and dry ratherquickly. I have used oil-based enamels,but have learned that they sometimesdo not release as easily from themylars after bagging and they arequite objectionable to work with inregards to clean up and odors. Withthe water based paints, I usually set abowl of clean warm water near bywhile airbrushing and either duringcolor changes or when changingnozzles, I’ll disassemble the nozzle andsoak it in the warm water. After a fewminutes, the water will remove most ofthe paint from the nozzle and it will beready for the next color.

My advice to the reader is to take yourtime and research the vast amount ofairbrushing options that are availableand pick a system that will meet yourcurrent and future needs. The low costsystems from Testors allow the entry-level builder access to equipment thatperforms well and is easily cleanedand maintained. The upper endsystems are much more durable andwill probably perform more reliablythrough years of use. Some additionalsystems for the reader to consider arethe upper end systems offered byTestors. These feature a lifetimewarranty on the airbrush body. Theupper end systems feature ergonomi-cally contoured airbrush handles thatare more comfortable to hold duringlong airbrushing sessions. They alsofeature a knob that allows to user toestablish limits on the maximumamount of air pressure that the triggerwill allow. This feature will greatlyreduce the likelihood of mistakes whenperforming fine, detailed work.Depending on the airbrushing systemchosen, Testors offers the system in anice wooden storage container thatfeatures storage areas for multiplenozzles as well as the airbrush body.These upper end systems can includethe assorted nozzles, a cleaning station,propellant cans and spare paint bottles.Expect to pay between seventy-fiveand two hundred dollars for a top-endTestors airbrushing system dependingon package contents.

Designing

My favorite aspect of remotecontrol gliding is hand launch.

Since these gliders generally fly much

lower than the larger gliders, anintricate paint scheme can be visiblyappreciated. And in truth, I admit thatI have a little vanity when it comes toflying unique designs.

Once I decided to make a paint schemewith a butterfly motif, it was time tomake some choices. Foremost, Idecided that I did not want to create asimilar butterfly pattern than DonStackhouse did. Instead I wanted tomake a unique design that was origi-nal in its own right. On another trip tothe library, I discovered several goodbooks about butterflies and moths.Some were better than others, but onethat stood out from the rest was,“Eyewitness Handbooks Butterfliesand Moths” by David Cater (DorlingKindersler, Inc. NY ISBN 1-56458-034-2hard cover or 1-56458-062-8 soft cover).This excellent book has many goodphotographs of many common andrare butterflies and moths. The glossypages bring out the brilliant patterncolors and also clearly show theintricate pattern designs. I was sur-prised to discover how many varietiesof moths have been discovered andthat there are many of them that do notfeature the typical brown, nondescriptpatterns that we envision whenimagining moths.

I decided to use this book to come upwith an inspiration for a butterfly ormoth wing pattern, but before decid-ing on a particular one to use, I neededto establish some guidelines on theeventual pattern that I wanted to use.The first restriction that I placed on adesign was the limitation of colors.Quite frankly, I did not want topurchase many different paints for asingle design. So I limited my totalcolor choices to three or four. Next, Iconsidered the amount of intricateairbrushing detail that would beneeded to make a design. Although afair amount of detailing was acceptableto me, I did not want to pick a designthat would take many hours toairbrush. Another important limitationwas how visible the wing patternwould be in the air. I reasoned that itwould not benefit me to have closelymatching colors that would blendtogether or closely resemble myintended solid-colored bottom surfaceof the wing. Before beginning, I hadalready determined that I wanted onlya solid color on the bottom of the wing.This was a personal preference and a

Photo 3

I purchased it from my local hobbysupplier for about one hundred andthirty dollars. While there, I alsopurchased an air pressure gauge and adevice called a water trap that elimi-nates the atmospheric water from theair expelled from the nozzle. Differ-ences in temperature of the warm aircoming from the air compressor andthe cool air in the hose connecting tothe airbrush will cause condensation.Moisture in the airbrush can also occurin humid environments. Moist air willalter the paint consistency and causethe airbrushed paint to unexpectedlyrun or sag across the painted surface asa result. This is most noticeable whenairbrushing on very smooth surfacessuch as waxed mylars. Although Ihave since found cheaper air compres-sors, I made the decision to supportmy local hobby dealer. The cheapestair compressor that I have since foundwas in an arts and crafts shop that wasretailing for about seventy dollars andalso featured a built in air gauge. OnceI began using an air compressor, I wasable to slow down and take my timewhile airbrushing. This has caused asignificant increase in the quality ofmy airbrushed patterns since I am notconstantly worried about running outof compressed air cans in the middle ofan airbrushing session.

The last item to consider before gettinginto airbrushing is the type of paint touse. In this case I can only recommendwater-based acrylic paints. These areeasily cleaned with water and in some

R/C Soaring DigestPage 8

choice that I made that would help tominimize the amount of airbrushdetailing that would be needed tocreate the wing design pattern.

I spent some time and looked throughthe pages of this book and discovereda very striking moth that caught myattention immediately. It was the FieryCampylotes moth (Family:Zygaenidae, Species: Campylotesdesgodinisi, Author: Oberthur). (Seephoto 4.) At first glance, most readerswould assume that this pattern wouldbe a butterfly due to its bright coloredpattern of reds, oranges, blacks andyellows, but the author does a wonder-ful job of showing that many of theworld’s most brilliant and astonishingcreatures are moths. The FieryCampylotes is native to India andalthough it is not confirmed, accordingto the author of the book it is believedto be poisonous. I have personallynever seen this moth, but I am surethat it would be striking to chanceupon it. I was drawn to the patternaesthetically by the predominate colorsof red, black and yellow. This mothpattern had many of the generaldesign ideas that I was initially seekingfor my hand launch wing: high con-trast between colors, different colora-tion between the tips and the rootareas, and a contrasting third color toprovide a pattern.

Our next step now is to come up withan initial wing design pattern. Readerswho anticipate that they do not havethe creative and artistic skills necessaryto do this can rest assured; the authorwill describe a method that is foolproof.

One of the easiest ways to create adesign pattern is with some cleartransparency sheets or with clear thinmylar. The reader can also use graphicdesign programs such as “Paint ShopPro” or something similar. I willdescribe how to create the designusing transparency sheets. Readerswho are adept at using computergraphic design programs can easilyadapt this concept to their digitalcounterpart methods.

The following items will now beneeded: a printout of the FieryCampylotes sketch, colored pencilsand a transparency pen that can beerased off of the transparency sheet.

Lay the transparency sheetover the moth printout anddraw and outline of one sideof the wing mylar plan form.This sketch does not need tobe to scale so don’t be tooconcerned about the minordetails of the sketch. Try toproduce a rough approxima-tion of one half of the wingequal to the size of one halfof the moth wing. This willassist us in spotting designelements.

Before explaining the nextseveral steps, it is importantto mention a major consider-ation of the design process.Keep in mind that there isno “correct” or “incorrect”design decision. The readershould seek a design thatpleases them and not beconcerned with trying tomake a design that isconsidered “perfect”. This isimportant since our nextsteps will be to pick apattern design as an initialstarting point. This will beaccomplished by moving thetransparency sheet with asketch of one half of thewing plan form over themoth pattern until somegeneral design elements arefound to be pleasing. In theillustrations that are pro-vided, I have used a com-puter program to display theoutline of the one half of thewing plan form over themoth sketch. (I found itdifficult to produce photo-graphs that would clearlyshow the examples to thereaders while using trans-parency paper.) What we aregoing to do is place thetransparency sheet that hasone half of the hand launchwing plan form over theprintout of the FieryCampylotes and slide itaround to see how thedesign elements of the mothpattern fall across the handlaunch wing plan form. Let’stake a look at some configu-rations that were discoveredby doing this. Attempt toline up the wing plan form

Photo 4

Photo 5

Photo 6

Photo 7

Photo 8

Page 9August 2002

terns. During the next steps,we will discuss how to createthe actual wing airbrushpattern from this choice. (Seephoto 7.)

Now, it is time to create ourairbrush design. Somereaders may feel like this iswhere they do not have theartist creativity to made adesign, but this is not so.What we are going to do islocate design elements in thepattern.

One of the first elements thatI noticed was the generaltrend of the black lines asthey gently curved downtowards the trailing edge ofthe wing root. On the actualmoth pattern, the linesactually stop at the moth’sbody, but since we are notgoing to model the moth’sbody in the final design, wecan ignore this for the mo-ment. On the transparencysheet, trace over these linesand instead of stoppingbefore the wing root,

difficult part of this process is nowcomplete! What we have just created isguide for our finished design. At thispoint, the readers can go back to thetransparency and add some additionaldesign lines if the sketch seems to betoo plain or erase some lines if thedesign seems to be too cluttered. Thereis no right or wrong design, so thereaders should not be concerned aboutattempting to create an exact replica ofthe moth pattern. Instead, attempt tocapture the essence of the moth designby tracing over the major designelements onto the transparency sheet.

We will now use our transparencysketch and transfer this design to somepaper towels. At this point, if you havenot already cut your hand launch wingmylars, go ahead and do so. Dispenseenough paper towels to span thelength of the top wing mylar from tipto tip. Do not separate the papertowels along the perforations, butrather leave them together. Now, usingthe top wing mylar, trace the wingplan form onto the towel using a darkmagic marker. (See photo 12.) Tracethe entire outline of the top mylarsurface, both left and right sides. Once

Photo 9

Photo 10

Photo 11

on your transparency sheet as closelyas shown in the examples.

In Figure 1, the general colors weresplit about half way along the wingbetween the reds and the yellows.Although I wanted this concept, I feltthat the yellows were taking too muchof the wing space. I could have stillchosen this design, but it just did notappeal to me. (See photo 5.)

In Figure 2, I was able to position moreof the yellow colors near the extremeends of the wing tip, but I felt that inthis position, there would not beenough yellow in the tips to makethem very visible in the air. (See photo6.)

In Figure 3, I felt that I had found anice balance between the reds and theyellows. I also liked how the blackcolor gently sloped towards thetrailing edge at an angle. Notice thatnear the wing root, the moth’s headand antenna are shown. This wouldnot be modeled in the final design, so Iwas not concerned about it. At thisstage, the readers should look only forvery general and vague design pat-

make the lines go all the wayto the wing root. (See photo8.)

Another element that Inoticed was the distinctiveblack edge near the tips andhow it curved gently fromthe leading edge to thetrailing edge. On yourtransparency sheet, trace overthis line. (See photo 9.)

And the last element is theyellow spots on the wing tips.Theses were easy to identify.Again, on the transparencysheet, trace over the yellowspots.(See photo 10.)

Once you are finished, yourtransparency sheet willappear similar to the pro-vided example. (See photo11.) Do not worry if yourdesign is not exactly like mymine. Every airbrushed wingdesign will be unique andwill not need to matchperfectly.

So, believe it or not, the most Photo 12

R/C Soaring DigestPage 10

finished, set aside the wing mylars fornow. They will not be needed againuntil we are ready to beginairbrushing.

Now, still using a dark magic markerand the transparency sketch that wecreated, transfer the design lines ontothe paper towels. The transparencysheet will be much too small, but itwill only be used as a guide fordrawing onto the paper towels.Attempt to sketch the design lines asbest as you can and do not worryabout making it identical to the designon the transparency. (See photo 13.)

The opposite side of the wing shouldbe a mirror image of the transparencysketch. To assist you in doing this,simply turn the transparency over andit will now reflect its mirror image andthe opposite wing mylar side. Don’t betoo concerned about making thedesign lines perfect on the papertowels, but try to draw the lines asclosely as possible. One trick that Ifound that helped me to make exactmirror images on both sides of thewing plan form on the paper towelswas to draw the design lines on onlythe right side of the wing and then foldthe paper towels in half along the wingroot intersection. (See photo 14.) Afterfolding the paper towels in half if youused a heavy dark marker to draw thelines for the right wing side, they willbe faintly viewable through the papertowels. Although you will be markingon the backside of the left wing half ofthe paper towels, go ahead and markover the initial lines that you justsketched. When you open the papertowels again, if the design sketch linesthat are on the back side of the papertowels can’t been seen well on thefront left side of the paper towels,simply trace over these lines as well.At this point, you will now have acomplete outline of the wing plan formon the paper towels as well as sym-metrical design lines on both halves ofthe wing plan form. If you now placethe top surface wing mylar over the

(top) Photo 13

(left) Photo 14

(right) Photo 15

paper towels and line it upthe wing plan form outlinethat you traced with a darkmarker, you will be able tosee the design lines that youdrew on the paper towelsthough the mylar. This willgreatly assist us when wecommence the next step ofairbrushing.(See photo 15.)

Painting

Before beginning, thereader should have

waxed and buffed the wingmylars as they wouldnormally do before baggingtheir composite hand launchwings.

The reader at this pointshould have obtained theirairbrushing system andunderstand the specifics onhow to operate it. With themany types and makes ofairbrushing systems avail-able, it is impossible to writeabout the specific operatingmethods of each one.Instead, I will mention thegeneral concepts associatedwith airbrushing. It will beassumed that the reader haspracticed and has obtainedsufficient skills to be able toaccurately produce thin andthick lines as well as be ableto accurately control theairbrush spray pattern. Thiswill take some practice and Irecommend using water inyour airbrush and practicethese skills on brownshipping paper. The ship-ping paper while it has beenairbrushed using water willmimic an airbrush paintpattern. When the wetshipping paper dries, thedark colored water spotswill return the paper back toa lighter color. The reader

Page 11August 2002

can then airbrush back over theshipping paper without needing to usemultiple pieces of practice paper. Thereader should become adept enough toconfidently produce thin and thickwavy lines, dashed lines, and consis-tent parallel lines without over spray-ing. Once this level of proficiency isobtained, the reader will be preparedto airbrush the design onto the mylars.

Earlier, we picked a moth pattern andcreated a hand launch wing designfrom it. We then marked the wing planform outline on paper towels by usingthe cut mylars as a guide and then weused our transparency sheet as thebasis for drawing the design on thepaper towels. Once the design lineshad been placed, we learned that wecould see these lines through themylars by placing the mylars over topof the paper towels and lining up theedges of the mylars with the outline ofthe mylars that had been traced on thepaper towels. This concept will greatlyassist us while airbrushing since all wewill need to do is follow the designlines that are visible though themylars. This is very much like thepaint-by-numbers concept and willgreatly assist us during the airbrushingprocess.

At this point, the reader should obtainthe necessary paint. The three basiccolors of this design will be red, yellowand black. I recommend that thereader purchase about two ounces ofeach color. You will have some leftover paint, but it is better to have somespare than to run out of paint duringan airbrushing session. Pick whicheverhue (variation of color) you can find orwhichever specific colors that youprefer. Make sure that you purchasewater based acrylic paints. These areeasy to clean and will easily releasefrom the mylars after bagging. Testorsoffers a wide assortment of colors ifyou have access to a nearby supplier.Another item you will need to pur-chase is airbrush thinner. This is notthe same thing as paint thinner, but itis the same concept. Airbrush thinneris used to thin water base acrylicpaints. Some paints can be thinnedwith water, but you will need to checkthe label to see which ones can bethinned this way. Before airbrushing,you will need to thin the paint to aboutthe consistency of milk. It should havea creamy appearance, but should notbe overly watery. Unfortunately, trial

and error will be the best teacherregarding this. One way to note if yourpaint mixes are too thin is that whileyou are airbrushing onto the mylarsurfaces, instead of the paint readilyadhering to the mylars, it will seem torun across the mylar surface. A paintmixture thinned too much will causethe paint to collect as small droplets onthe surface of the mylars. This willcause the dreaded fisheyes. Fisheyeson the mylars will appear to be smallcircular areas where the paint does notseem to want to stick to. If the builderelects to bag the wing without repair-ing the fisheyes, the foam will bevisible through the fiberglass skins. Ifthe paint mixture is too thick, it willnot seem to want to come out of thenozzle unless you use too much airpressure. Too much air pressure willcause over spraying of the paintmixture and can cause the consistencyof the paint mixture to vary. If youelect to use the portable compressedair cans, a thick paint mixture may noteven exit the nozzle. Practice willgreatly assist in learning how thick orthin to make your mixtures. Be sure toalso mix up more paint than youexpect that you will need. If you runout of the mixed paint whileairbrushing, it is almost impossible tomake an identical batch. This is eventruer when mixing paints to makecombination colors. As a general rule,a light coating of paint on the surfacesof a sixty-inch wide hand launch wingwill need about one half to one ounceto cover the entire surface. Lightercolors will need slightly thicker coatsto become opaque and darker colorswill need less coat layers to become so.Keep this in mind when mixing upyour paint batch.

Since we can easily view the outlinesof our Fiery Campylotes designthrough the mylar surfaces, it is nowjust a matter of airbrushing over thelines. First, cover up the bottom mylarsurface with either paper towels orwith shipping paper and place some-thing on top of it to keep the com-pressed air from the airbrush fromblowing it away and allowing paint toland on the bottom mylar. We will bepainting the bottom surface of thewing last and this will prevent anyover sprayed paint from landing onthe bottom wing mylar. I like toposition the mylar surface that I amcurrently working on closest to mesince then I do not have to reach over

the opposite mylar while airbrushing.Next, mix up and properly thin a batchof black paint and begin airbrushingover the major design lines. You’llwant to build up the paint thicknessgradually in multiple layers. Whenairbrushing, remember the followingguidelines: maintain the airbrushnozzle at a consistent distance from themylars, attempt to maintain a setwidth of the spray pattern, use yourarm to control the nozzle and not yourwrist, and most importantly, only uselight misting coats. You will discoverthat these light coats will dry ratherquickly. One neat airbrushing trick isto use the airbrush to send out airwithout any paint to help theairbrushed paint dry quickly, but Iwould not recommend this if you areusing compressed air cans since youwill quickly empty your supply. If youonly spray on light misting coats, itwill take about a minute or less to dry.As you are airbrushing the black paintlines onto the mylars, you will want tobuild up the paint thickness onlyenough to cover the design lines on thepaper towels that are showing throughthe mylars. You will probably find,that depending on how thick or thinthat you have mixed your black paint,you will not need many coats to buildup the paint layer. One importantconcept to remind yourself of is thatthick paint layers will make your handlaunch wing significantly heavier, soalways attempt to place the leastamount of paint that you can.

Once you have airbrushed and cov-ered all of the black design lines on themylars, you are now ready to fill in thelarger areas of black coloring. You willnotice on the tips of the wing, there areareas around the yellow spots that willneed to be airbrushed black. First,outline all of the yellow areas with athin black line. This will assist you asyou start to fill in the black coloredareas since it will visibly indicatewhere the yellow areas will begin inthe pattern. Airbrush all of the blackareas in the tips. Attempt to get aconsistent fill with even paint cover-age. Remember that you only needenough paint to make the mylarsopaque. With the white paper towelsunder the mylars, this is easy to judgethis since any spot on the mylarsurface that does not have enoughblack paint will continue to reveal thewhite paper towels through the mylarsurfaces. The contrasting color of black

R/C Soaring DigestPage 12

paint and the underlining white papertowels will be easily discerned. Takeyour time and attempt to do a good jobsince any mistakes will be clearlyshown on the finished wing. Anothertrick that I have learned since I beginairbrushing is that you can carefullylift up the mylar surface and look atthe outside surface of the mylar. If youhave a strong light source in the room,you can easily see the variations ofpaint coverage and spot any placeswhere the paint needs to be placed alittle thicker. This makes it easier to seevariations in paint thickness, especiallywhen using the lighter colors.

Once you are finished with the blackairbrushing, clean out your airbrushand mix up some red paint. Now it istime to fill in the red colored areas onthe mylars. Do this the same way thatyou filled in the black colored areas inthe wing tips. Do not airbrush over thedried black paint already on themylars. You’ll want to spray closely upto the existing lines. With the airbrush,you will be able to accurately controlthe paint at it lands on the mylarsurface by adjusting the paint flow rateas well as the diameter of the pattern.After airbrushing all of the red coloredareas, clean the airbrush again andthen fill in the yellow spots in the wingtips with a new batch of yellow paint.

The last stage is to paint the bottomsurface once the top has dried. Themylars can be carefully handled oncethe paint is dry, but be sure not toscratch the newly paint surfaces or itwill show on the bagged wing. Ielected to paint my entire bottomsurface red, but the reader can chose topaint a similar moth pattern on thebottom if they desire. My rationale forthe solid color for the bottom skin wasto ease visual orientation while flying.

Be sure to clean out your airbrushthoroughly once you are doneairbrushing. Clean equipment willmake your next airbrushing sessionmuch easier and less frustrating. It ismuch more difficult to remove paintwhen it has dried than while it is stillwet.

Allow the mylars to dry to the touch.You will be able to lay up your fiber-glass and epoxy once the airbrushedpaint has dried. You’ll also want to use

care when spreading theepoxy. The paint will notreadily chip off, but it willscratch off against sharpobjects. Continue your normalbagging process and prepareto be amazed when the lay uphas cured and the mylars areready to be removed. Use carewhen removing the mylarskins since the epoxy will stillbe curing, and although thepaint will not flake off fromtouching the newly bagged

Troubleshootingand Conclusion

We conclude the tutorial onairbrushing butterfly and moth

patterns onto composite bagged wings.Earlier, we airbrushed a moth patternonto the mylars for a compositebagged hand launch wing and baggeda wing with the pattern airbrushed onthe wing mylars. Hopefully when youremoved your hand launch wing fromthe vacuum bag you were delightedover your creation, but more thanlikely, you might have had a fewplaces on the airbrushed pattern thatdid not come out as well as you hadexpected.

Let’s review some of the commonmistakes of airbrushing and what youcan do to eliminate or minimize themfrom occurring.

Over spray (Photo 17.)

This occurs when a small amount ofwet paint is left on the nozzle whenstarting the airbrush stroke. This paintwill be propelled off of the nozzle andwill splatter on the mylar surface.Paint splatters are easily fixed by usinga soft tissue or a q-tip and carefullywiping the spattered paint off of themylar. Don’t be too concerned withany paint streaks that occur as a resultof doing this since you can easilyairbrush over the streaks and coverthem up. If it is possible, always beginyour airbrushing off the edge of themylars so that if the initial airbrushspray contains any paint splatter, itwill not land on the mylars. Sometimesyou will not be able to start yourairbrushing off of the mylars such aswhen you painted the yellow spots on

Photo 16surfaces, the still curing epoxymight capture your fingerprintsforever.

Depending on your attention todetail and your proficiency whileairbrushing, I would estimate thatthis whole process should takeabout an hour to create the designpattern and about an hour to dothe airbrushing. I have sincediscovered that by pre-mixing mycolors before hand, I can reducemy airbrushing time significantly.Another item that I have sincepurchased is an airbrushingcleaning station. (See photo 16.)This is a device that allows you toplace your dual action airbrushnozzle into a receptacle on a glassjar lid that is equipped with an airfilter. To clean my airbrush nozzlebetween colors and before the finalclean up and storage, I simplydisconnect the paint jar from theairbrush handle and connectanother paint jar that has airbrushthinner in it. I run the thinnerthrough the nozzle into the clean-ing jar until the spray pattern nolonger shows any paint. This canalso be done with water if youwant to conserve your airbrushthinner supply. It is easy to seewhen the nozzle is clean since youcan see through the jar and watchas the airbrush spray progressivelybecomes clearer as the paint isremoved from the nozzle. Clean-ing up the jar is simply a matter ofunscrewing the lid, discarding theresidue and rinsing out the jarwith water. The air filters arereplaceable. This station cost abouttwenty-five dollars and replace-ment filters are about five dollars.The one that I purchased is alsomade by Testors.

Page 13August 2002

the wingtips. When faced with thissituation, check and see if there is anypaint residue on the nozzle and if so,gently wipe it off. Also, when startingyour airbrushing pattern in an area onthe mylar that is not adjacent to theedge of the mylar, begin the spraypattern slowly by adding air withoutpaint and then gently increase thepaint levels until the desired airbrushpattern is obtained.

Over spray can also occur if the userdoes not maintain the airbrush at a setdistance from the mylars and if theuser suddenly increases the amount ofpaint in the airbrush pattern. Thesemistakes can also be repaired by gentlyblotting the excess paint off the mylarswhile it is still wet and re-airbrushingthe paint back on.

Scratches (Photo 18.)

One thing that I still must be careful ofis ensuring that any portion of theairbrush does not come into contactwith the painted mylar surfaces.During my first efforts at airbrushing, Ifound that I would often carelesslyallow the paint container to rub acrossthe already painted areas on the mylarand remove small amounts of paint.Airbrushing back over the scratcheseasily repaired the paint void, but ifoften meant that I needed to set up myairbrush for that particular color againif I had changed colors withoutnoticing my mistake. I still sometimesfind that I scratch the dried mylarswith the airbrush equipment, but bypaying careful attention whileairbrushing I do not make it as often.

Mixing (Photo 19.)

It has been my experience that overlap-ping paints in the attempt to make acombination color such as coveringdried red paint with yellow paint tomake the resulting color orange doesnot work well at all. If you desire aparticular color, mix it beforehand andthen airbrush it onto the mylars. Youmight get a faint mix color fromoverlapping airbrush paints, but itwon’t be in the intensity and clearnessthat you will expect. Actually, I foundthat it doing this actually did not lookpleasing at all.

Clean patterns (Photo 20.)

I find that as I continue to becomemore adept in using the airbrush that Ido not make many mistakes inairbrushing over existing paintedareas. In the beginning, I had troublecontrolling the spray pattern/widthand would often accidentally overlapairbrush patterns. Practice will allowyou to perfect the necessary airbrushdexterity skills. One idea to rememberwhen painting butterfly and mothpatterns is that just like real butterfliesand moths, their own wing patterns donot have cleanly separated patternlines, but instead have somewhat of afeathering pattern as the colors gradu-ally transition from one to another.Often, though, you will need to lookvery closely in order to notice it. Whenairbrushing your own butterfly andmoth designs, remember this concept.Most of the time, your hand launchwill be flying at a distance, and youwill not be able to see the small minordetails of the design pattern. I havefound that when airbrushing adjacentcolors, allowing the spray pattern togently feather into the adjoining colorproduced pleasing results.

I certainly hope that this tutorial hasgiven you some ideas and inspirationsto attempt your own butterfly/mothpatterns on hand launch wings,however all of the concepts andinstructions covered in this tutorial canbe easily applied to larger compositebagged wings. With an airbrushingsystem, you can elect to do as simple

Photo 17

Photo 18

Photo 20

Photo 19

R/C Soaring DigestPage 14

or as complex of a pattern that youcare to create.

In conclusion, I would like to presentthe reader with some other butterflyand moth patterns that I have de-

signed, but have not yet airbrushedthem onto a hand launch wing. Feelfree to use them as a guide to createyour next masterpiece, but permissionis not granted to reproduce them forcommercial purposes.

Good luck to you as you continue inyour airbrushing experiences. If youcreate a butterfly or moth hand launchwing design, be sure to send me aphoto of it. I would be very interestedin seeing your creation!

Page 15August 2002

Joedy DruliaShenandoah Valley, Virginia

joedydrulia@hotmail.comn

R/C Soaring DigestPage 16

GORDY’S TRAVELS

Gordy StahlLouisville, KentuckyGordySoar@aol.com

Servo Jitters and Repairs

Igot a call from a guy who got amolded plane second hand, it had

top brand servos in it. He had it for ayear or two and didn’t like flying it,but some new wings became availablefor it and he started flying it again.During a contest, the sailplane waspassing over some trees and suddenlynosed down hard, leaving the planespieces spread between two trees.

Upon inspection all he could find wasthat one of the V tail servos was actingerratically, so he assumed that waswhat caused the crash. He wasbummed of course and his reactionwas a desire to let the servo manufac-turer know how unhappy he was. Hemade the comment that he will,“Never use that brand servo again!” Inspite of the fact that the servo hadperformed reliably for a couple ofyears.

So what IS the manufacturers responsi-bility in a situation like that? The servoserved its original purchaser and thesecond owner well, and in fact it’sunlikely that the servo was the culpritthat caused the dive/crash.

Our suppliers all try to make a greatproduct, they all have disclaimersabout responsibility and liability, butnone can protect themselves from anangry modeler’s frustration. All theWorld Class Championships, extremeevents successfully completed, WorldRecords or use by world class pilots,can’t balance that one sad story.

• So what happens to servos thatwhen they act up?

• When should you have them‘serviced’?

• What is the ‘break even’ price thatmakes refurbishing servos a value?

Servos consist of parts, some plastic,some electronic and some mechanical.Counting the case, gear deck, and wire,you have four main components:

The GearsThe Pot

The Amplifier, andThe MOTOR

The ham bone is connected to the ....

Your battery is the source of yourservo’s power. What comes out of thebattery, ends at the servo motor’sbrushes and commutator.

‘Brushes’ consist of tiny and very thin‘whiskers’ of Palladium that lay on foilthin copper acting as the commutator.(Except for the Volz XP and HP series,they have motors with carbon brushesfor extreme use like DS’ing.)

What happens when you short thewires of your battery - at the battery?Excitement right? Well that’s whathappens at the servo motor brusheswhen you hang the flap in the grass orthe elevator against a branch while in atree. They get HOT, but who cares —you can’t see em so its probably notimportant.... 5 cells really makes themglow, but what the heck it makes theservo stronger and it must be okay cuzthe box shows a spec rating at 6volts..... Not bad.

Servo jitters are usually a result ofcooked servo motor brushes. Themotor tries to move but the powerconnection is charred, sort of like adirty battery connection in your car.We want the servo to micro center; todo that the motors need to power!

Pots used to be ‘cleanable’ and theyneeded it, when used in Glow Fuelpowered planes that got dirty andvibrated at high frequencies, but Potsmaterials have changed, so it’s un-likely a servo centering problem willbe a Pot problem.

Amplifiers either work or don’t. They‘fail’ when they receive a reversepolarity surge (oops! Red to black,black to red). And they ‘fail’ when theyget hot and they get hot when over-currented during a stalled servosituation... Another reason to stayaway from 5 cell packs.

It is usually the motors, which growold. Over heating a servo motor causetheir magnets to loose their magnetismwhich means weaker motors.

Long servo arms put greater loads onthe servos which are trying to do theirjob on a launch. Never use more than atwo-hole arm connection!

Sending your servos in for ‘refurbish-ing’ seldom makes sense money-wize.One big consideration is the compe-tency of the repairman. If he is a RCsailplane pilot himself, chances arehe’ll take more care and considerationwhen checking your servo. Unfortu-nately you can’t interview the repair-men when you ‘send’ you servos in toa manufacturer. Some manufacturersrecognize the lack of skill and interestof servo repairmen and simply chargea flat rate, for an ‘exchange’.

Most guys think that it’s gears thatneed replacing and, depending on thematerial of the gears they could beright, but mostly it’s the motor thatshould be replaced.

If you have been using 5 cell packs,then definitely replace the motors.

Gear pins are another part that is oftenoverlooked, they bow as the gears areloaded and try to move away fromeach other. A small bend in a gear pinis hard to see but shows up in center-ing as either slop or binding.

‘Metal’ gears vary in their material.Often they are made of powderedaluminum or soft brass, but it still isseldom that those parts wear, insteadyou’ll find that the culprit is gear slop,the single plastic gear in the train.

So how about that poor guy’s prob-lem? Well, he’ll never be happybecause he lost an expensive plane,

Page 17August 2002

and he’ll never be convinced thateverything man made wears out,burns out or just breaks. He’s surethat the servo never was underdamaging stress, and he’ll neverknow that the servo’s problemwas a result of the crash, not thecause.

He’ll never believe that by badmouthing a supplier that it won’tmake his plane come back or helpimprove products in the future...

How do you decide which brandto use in your sailplane? Do yourhomework... Does the brand youare considering offer servomounts for mounting in sailplanewings? What are the gears madeof? Size, weight, torque andspeed, all should be matched tothe application.

Servo ‘tester’ devices are mostlygimmicks, since they are less than‘precise’ and, just seeing currentdraw, don’t tell you if your servoswill last through a hard conditionsituation.

Servos do work, meaning theywear out. Their parts can bereplaced, but in the end, it’s newservos that make the best $ensefor your favorite plane.

Our servos and our suppliers getreputations, you should be able totell which are earned and whichare gossip. We are lucky becauseall of our equipment is far morereliable than ever in the past. Ihope that trend continues.

Think about those motors! n

R/C Soaring DigestPage 18

Now available: complete line of glider accessories: Canopies, Markings, Retract L/G, Airbrakes, etc.

Nimbus 4-D130" Wingspan$599.95

Duo Discus98" Wingspan$499.95

P.O. BOX 6004, SAN CLEMENTE, CA 92674 - Phone (949) 425-1362/FAX 349-0829WWW.HOBBYCLUB.COMCALL FOR FREE CATALOG

Ga

lle

ry o

f G

lid

ers

Specs. ASW-24 PILATUS B-4 LUNAK LF-107 DISCUS (1:3.5) DG 800 (1:4.5) NIMBUS 4-DWing Span: 64 in. 57 in. 66 in. 168 in. 137/165 in. 130 in.Length: 28.3 in. 29.5 in. 28 in. 74 in. 62.5 in. 46 in.Wt: 11 oz. $159.95 10.5 oz. $149.95 15 oz. $159.95 200 oz. $1395.95 123 oz. $999.95 54 oz. $599.95

ZIKA

Page 19August 2002

T.W.I.T.T.(The Wing Is The Thing)T.W.I.T.T. is a non-profit organization whosemembership seeks to promote the researchand development of flying wings and othertailless aircraft by providing a forum for theexchange of ideas and experiences on aninternational basis. T.W.I.T.T. is affiliatedwith The Hunsaker Foundation which isdedicated to furthering education andresearch in a variety of disciplines. Fullinformation package including one back issueof newsletter is $2.50 US ($3.00 foreign).Subscription rates are $20.00 (US) or $30.00(Foreign) per year for 12 issues.

T.W.I.T.T., P.O. Box 20430El Cajon, CA 92021

The Eastern Soaring League (ESL) is a confederation of Soaring Clubs, spread across the Mid-Atlantic and New England areas, committed to high-quality R/C Soaring competition.AMA Sanctioned soaring competitions provide the basis for ESL contests. Further guidelines arecontinuously developed and applied in a drive to achieve the highest quality competitionspossible.Typical ESL competition weekends feature 7, or more, rounds per day with separate contests onSaturday and Sunday. Year-end champions are crowned in a two-class pilot skill structureproviding competition opportunities for a large spectrum of pilots. Additionally, the ESL offers aRookie Of The Year program for introduction of new flyers to the joys of R/C Soaring competition.Continuing with the 20+ year tradition of extremely enjoyable flying, the 1999 season will include14 weekend competitions in HLG, 2-M, F3J, F3B, and Unlimited soaring events. Come on out andtry the ESL, make some new friends and enjoy camaraderie that can only be found amongst R/CSoaring enthusiasts!

ESL Web Site: http://www.e-s-l.orgESL President (99-00): Tom Kiesling (814) 255-7418 or kiesling@ctc.com

The League of Silent Flight (LSF) is an internationalfraternity of RC Soaring pilots who have earned theright to become members by achieving specificgoals in soaring flight. There are no dues. Once youqualify for membership you are in for life.The LSF program consists of five “AchievementLevels”. These levels contain specific soaring tasksto be completed prior to advancement to the nextlevel.Send for your aspirant form, today:

League of Silent Flightc/o AMA

P.O. Box 3028Muncie, IN 47302-1028 U.S.A.

http://www.silentflight.org

SailplaneHomebuilders

Association (SHA)

A Division of the SoaringSociety of America

The purpose of theSailplane HomebuildersAssociation is to stimulate interest in full-sizesailplane design and construction byhomebuilders. To establish classes,standards, categories, where applicable. Todesiminate information relating to constructiontechniques, materials, theory and relatedtopics. To give recognition for noteworthydesigns and accomplishments.SHA publishes the bi-monthly SailplaneBuilder newsletter. Membership cost: $15U.S. Student (3rd Class Mail), $21 U.S. RegularMembership (3rd Class Mail), $30 U.S. RegularMembership (1st Class Mail), $29 for All OtherCountries (Surface Mail).Sailplane Homebuilders Association

Dan Armstrong, Sec./Treas.21100 Angel Street

Tehachapi, CA 93561 U.S.A.

Classified Advertising PolicyClassified ads are free of charge to subscribersprovided the ad is personal in nature and does notrefer to a business enterprise. Classified ads thatrefer to a business enterprise are charged $5.00/month and are limited to a maximum of 40 words.RCSD has neither the facilities or the staff to inves-tigate advertising claims. However, please notifyRCSD if any misrepresentation occurs. Personalads are run for one month and are then deletedautomatically. If you have items that might be hardto sell, you may run the ad for 2-3 months.

For Sale - Business

PARACHUTES: $12.50 (includes S&H U.S.A.)Send check or money order to Dale King, 1111Highridge Drive, Wylie, TX 75098; (972) 475-8093.

Summary of Low-Speed Airfoil Data - Volume 3 is reallytwo volumes in one book. Michael Selig and his studentscouldn’t complete the book on series 3 before series 4was well along, so decided to combine the two series ina single volume of 444 pages. This issue contains muchthat is new and interesting. The wind tunnel has beenimproved significantly and pitching moment measure-ment was added to its capability. 37 airfoils were tested.Many had multiple tests with flaps or turbulation ofvarious configurations. All now have the tested pitchingmoment data included. Vol 3 is available for $35. Ship-ping in the USA add $6 for the postage and packagingcosts. The international postal surcharge is $8 for surfacemail to anywhere, air mail to Europe $20, Asia/Africa$25, and the Pacific Rim $27. Volumes 1 (1995) and 2(1996) are also available, as are computer disks contain-ing the tabulated data from each test series. For moreinformation contact: SoarTech, Herk Stokely, 1504N. Horseshoe Circle, Virginia Beach, VA 23451 U.S.A.,phone (757) 428-8064, e-mail <herkstok@aol.com>.

Reference Material

BBS/Internet

Internet soaring mailing listserve linking hundreds ofsoaring pilots worldwide. Send msg. containing theword "subscribe" to soaring-request@airage.com. The"digestified" version that combines all msgs. each dayinto one msg. is recommended for dial-up users on theInternet, AOL, CIS, etc. Subscribe using soaring-digest-request@airage.com. Post msgs. tosoaring@airage.com. For more info., contact MichaelLachowski at mikel@airage.com.

Books by Martin Simons: "World's VintageSailplanes, 1908-45", "Slingsby Sailplanes","German Air Attaché", "Sailplanes bySchweizer". Send inquiries to: Raul Blacksten,P.O. Box 307, Maywood, CA 90270,<raulb@earthlink.net>. To view summary ofbook info.: http://home.earthlink.net/~raulb

There is a growing interest in scale soaring inthe U.S. We are dedicated to all aspects ofscale soaring. Scale soaring festivals andcompetitions all year. Source for informationon plans, kits, accessories and other peopleinterested in scale. For more information:

web site: www.soaringissa.org

InternationalScale SoaringAssociat ion

R/C Soaring DigestPage 20