The Aerosente Glider Workshop

Hall Cherokee II 1:4

Hall Cherokee II 1:4 Scale

The Hall Cherokee II 1:4 This exclusive laser cut short kit with complete hardware pack is one of our most popular sailplanes. The never-before-modeled Hall Cherokee II was originally featured in a construction article by David Smith in Quiet Flyer magazine and is now kitted exclusively by TMRC with his permission.

This beautiful example of the Hall Cherokee II was scratch built by Earl Mosley in California and shows off the extremely scale structure of this great-flying quarter-scale design engineered and prototyped by Canadian modeler Dave Smith.

Stan Hall brought affordable high performance soaring to the masses with his well thought out all-wood construction Cherokee II. Available in plans beginning in the 50s, this aircraft has been built and flown by enthusiasts around the world. One in need of completion but with compete fuselage and tails recently was sold on eBay for less than a thousand dollars.



This is a classic in every sense of the word, and Dave has modeled it perfectly. His plans show a sport scale wing as well as drawings to finish the wing as per the full scale ship and much of the fuselage and tails construction is almost indistinguishable from the full size since he worked from Stan Halls original Cherokee II prints.

Just as in the full-scale world, many examples exist and in the images here you can see both flat-wrapped plastic canopies as well as blown molded ones. Both are correct and scale.

It is an excellent flyer by all reports and make a great subject for aerotow and can be successfully winched as well.

SPECS

Span: 132" (3.3m)
Length: 64.9" (165cm)
Aspect: 13.6:1
Area: 1280 in.2
All up weight: 6.5 lbs. (2.95kg)
Wing loading: 11.7 oz./ft.2
Airfoil: GOE 649
Scale: 1:4
No. Servos Req'd: 5-7
FUNCTIONS: Rudder, Elevator, Dive Brakes, Ailerons, Tow Release (optional)

PARTIAL KIT CONTENTS

Plywood and balsa wing ribs,
Plywoood fuselage bulkheads,
Cockpit floor/servo tray,
Balsa turtledeck formers,
Plywood nose formers,
Tail ribs, spars and tips,
Dive brake doors and frames,
Wing root fairing plywood sheeting,
Canopy bow templates,
Plastic canopy sheeting,
Vacuum-formed clear plastic canopy
Laser Cut Instrument Panel Kit
Plans, 2 sheets 36" x 84" rolled.

INCLUDED IN HARDWARE PACK

Lightweight wheel/tire 3-1/4" dia,
Steel wire axle, 5/32",
Dura collars 5/32",
3-48 x 3/4" stab mounting bolts,
Hinges, nylon large,12,
Pushrods (tails) 2 48" length,
3/8" 7075 T6 aluminum wing rod,
13/32" OD brass joiner sleeve,
square tube elevator actuator slide,
1/8" x 6" spring steel incidence pin,
5/32" OD brass incidence sleeve,
1/16" dia. wire tow release wire.

NEEDED TO COMPLETE MODEL

Wing and fuselage balsa sheet,
Wing balsa leading edge stock,
Spruce spars caps,
Fusleage framing longerons/stringers,
Cable actuators (dive brakes) 2,
Adhesive epoxy and CA cements,
Covering, fabric or film,
Servos, wires, battery and receiver.

ORDERING 

The Hall Cherokee 1:4 scale kit costs $329.95 and includes hardware package, fiberglass instrument panel kit and vacuum-formed canopy. Click the link below to purchase.

PLANS SHEETS: We offer plans sets for the Hall Cherokee 1:4 scale - 2 - 36" x 84" sheets - Price $44.95. Click the link below to purchase.

 
 

  

FINE ART PRINT: We offer a fine art print of the Hall Cherokee. These fine art aviation prints are meticulously drawn to scale using factory documentation and photographs and show panel lines or framing details and, where applicable, military insignia placement. The name of the aircraft depicted is imprinted along with detailed specifications, performance and historical data. Each is printed in high resolution on museum-quality archival stock in black-and-white or six-color process archival inks and shipped flat in a protective photo-mailer. Frame size is 16" x 20" using an 11 x 14 mat opening.The cost is $24.95. Click the link below to order:

 

HISTORY

The Cherokee II was introduced in 1956 by Stan Hall specifically for amateur construction from plans. The entire airframe is covered in fabric. Upper surface spoilers control the glidepath, and the landing gear is fixed.

Many examples vary in detail. The design was further developed by several builders including the Cherokee RM by Terry Miller and John Ree with a 13.4 m. / 44 ft. span wing with NACA 64(3)-618 airfoil which increased L/D max. to about 28, and the 15 m. Leonard Annebula which has Prue type trailling edge airbrakes and a claimed L/D max. of 31.

A Cherokee RM belongs to the National Soaring Museum.

ACKNOWLEDGMENT
Special thanks to the Soaring Society of America (SSA), for permission to use text and specs from their publications. More information on vintage soaring craft may be found at their pages and in their publications and those of the Vintage Sailplane Association.

ORDERING INFORMATION

All of our kits are hand picked and packed from parts we either fabricate ourselves or purchase from a small trusted group of suppliers and vendors. Each kit is unique and generally ships in 4 weeks or less. We maintain a stock inventory of some of our more popular kits which generally ship within 3-5 business days of the order being placed.

Aerosente guarantees this kit to be free from defects in both material and workmanship. If any parts are missing from the kit or are damaged due to workmanship of the product, please notify Aerosente for a prompt replacement of damaged or missing part. This warranty does not cover parts damaged by shipping, use or modification. Aerosente's liability will not exceed the original cost of the purchased kit. Aerosente does not control the assembly or materials used for final assembly, so no liability shall be assumed nor accepted for completed kits.

We accept a variety of payment methods including paypal and credit cards through paypal invoicing. Please email us at bolt55@aerosente.com or call 816.337.8807 or 415.234.6757 if you have any questions or need assistance with ordering, we appreciate your business!

The Lawrence Tech IV Laister Yankee Doodle

Now that the SGS 1-26E is complete and ready for cutting in quarter scale, I've put the 1938 Lawrence Tech IV, Yankee Doodle Sailplane NX18459 back on my desktop for final development at third and quarter scale.

OVERVIEW

Beginning with the larger of the two at 186" (15 1/2 ft. or 4.7 meters) span it will be drafted in exact scale (as much as possible) using scaled same wing, empenage and fuselage structural member spacing. Airfoil will be the scaled full size NACA 4418 transitioning to NACA 4416 at mid-section and to NACA 4409 at the tip with 4 degrees of washout. This should provide great slow speed turning to center in smaller thermals while still providing the ability to range well between thermals at this large scale. I will draft it with the earlier four-light flat-wrapped glazing on the canopy and will likely offer a vacuum formed part to replace this at some time in the future.

This is another fine example of the short-span theory of design of that era which resulted also in the 1937 Harland Ross - Harvey Stephens RS-1 later known as Zanonia which used the similar NACA 24 series airfoils and went on to set and hold more records than any other sailplane of its time. I've decided to complete plans and kit of the Laister first over the Ross-Stephens due to the relative lower complexity of designing and building a fuselage that is stringer on frame with fabric covering vs. the plywood-on-bulkhead monocoque construction of the latter. We will however release similar scale RS-1s in the very near future.

Here are the full size aircraft specifications for the LT IV as we will be designating it for those of you who love to do area vs. cubic vs. span loading calculations:

Structure Weight: 124.7 kg
Flying Weight: 214.3 kg
Wing Span: 14.173 m
Wing Area: 12.5 sq m
Wing Loading: 17.14 kg/sq m
Root Chord: 137.2 cm
Tip Chord: 50.8 cm
Aspect Ratio: 15
Fuselage Length: 5.867 m
Stabilizer Span: 269.2 cm

All for now.

CONSIDERATIONS FOR KITTING THE LAWRENCE TECH YANKEE DOODLE

I've done quite a bit of research into possible solutions to the method I would like to employ in the design of the Lawrence Tech IV sailplane kit. Some of the considerations are a given based upon the methods of construction I've used in the past for previous kits such as bulkhead and stringer fuselage. Others needed considerable more thought and analysis of the advantages and disadvantages from both a design and buildability standpoint while still offering the most scale interpretation of the original design.

Those areas of wing construction assessed include a faithful reproduction of the arc of the wing at mid-span, a viable and simple method of wing joint to the fuselage, ease of building the faired wing root area, and a simple and effective way to build washout into the outer panels. The methods chosen for these are to build the spars as complete double-tapered (both in frontal and plan view) assemblies first which allows the wing to be built without jigs or fixtures as single-piece left and right panels. By extending the spar into the fuselage by protrusion from the root rib, wing joining can be accomplished without the use of separate joiner rods, plates, or coupling devises.

By using slots fore and aft of the boxed wing spar assemblies, fore and aft rib sections are easily cemented to the faces of the spar by simply clamping each to the workbench while this operation proceeds, using only a square and the notched leading edge to fix the ribs square and parallel.

Many designs simply join to flat panels to make the gull-wing anhedral bend of the wing at mid-span but I didn't find that to be a satisfactory trade-off to scale realism and quality, so a different approach was needed without adding complexity to the parts or build.

Similarly, washout can be easily achieved in this method by simply varying the half-rib shapes and therefore their angle relative where each tabs into the face of the spars. As stated above too, a spar constructed in this fashion lends itself to being tapered in plan view, reducing mass at the wing tips and in a much simpler method than would be needed using the method employed using cap-and-web constructed spar systems. In addition, this method vastly reduces parts count and construction time by eliminating multiple shear webs being placed between each rib pair in tedious progression or the need to custom cut or fit each of these as the wing build progresses. The shear load bearing is accomplished instead by the completely boxed spar assemblies with the added benefit of highly accurate anhedral  and wing mounting angles more easily accomplished than using other methods.

For movable surfaces, the use of enclosed hinge lines with gap seals for all such joints was studied and simple methods of building these features into the sheeting and hinge spars was chosen for these.

Finally, fuselage construction is designed to proceed likewise without the aid or need of any jigging fixtures or special tooling. By building the square and parallel wing root area flat on the work table first and using a removable center spline to align and cement in the forward and aft formers this may easily be accomplished. Lower formers in the forward fuselage along with the attendant formers for the lower stringers will be added after the majority of the fuselage construction is complete.

As has been the case with previous designs, features will be designed in to allow removal and replacement of major assemblies such as hinged surfaces and empenage for servicing and transport and instrument panels and decal kits will be standard equipment as planned with all of our "Giant Scale" kits and provision for pilot seat and fully hinged canopy is also being considered.

KIT SPECIFICATIONS

Fuselage Length: 92.4" (235 cm)
Overall Height: 25.2" (63.8 cm)
Rudder Span: 18" (45.7 cm)
Stabilizer Span: 35.3" (84.7 cm)
Wing Span: 186" (4.7 m)
Aspect: 15:1
Airfoil: NACA 4418-4416-4409
Wing Area: 2312.5 in.²
All up Weight: 24 lbs. (11 kg) (estimated)
Wing Loading: 24 oz./ft.²

"My Heart Soars" - Howard E. Burr

Howard (Chip) Burr Jr. sent me a copy of his dad's memoir My Heart Soars which arrived in today's mail. Its absolutely wonderful and I can barely put it down without reading it through all of its short 72 pages.

Although self-published without the aid of an editor, its stories of early gliding from 1929 forward through the 50's, fondly told memories of associations and friendships with the early pioneers including Paul and Ernie Schweizer is priceless. I would say that this book brings out what it was like to live and fly and work in aviation in the early days, providing insights into the personalities, daily lives and soaring adventures of all of the greats like none other that I have read.

It is accompanied with many black and white photos of the many sailplanes described throughout the book, including three-view of the SGS 1-24 Brigadoon (on the cover) developed by Ernie and several images of the single copy built from Schweizer parts by Howard himself and successfully flown to several personal records.

A must read for any vintage soaring enthusiast and historian. Thanks Howard and for inscribing my copy.

You can get a copy by writing:
Howard Burr
785 Tucker Road G310
Tehachapi, CA 93561

Making Scarf Joints in Structural Members of Scale Balsa Sailplane Models

I just had a conversation with Mike about scarfing the joints in the spar caps for his current build, the SGS 1-23H at quarter scale. Because spruce stock from hobby suppliers generally comes in 36" and 48" lengths, two or more pieces must be joined to make a spar cap continuous for a wing panel greater than those lengths. That includes just about any sailplane with greater than 96" (2.4m) span.

Here are a few key points to keep in mind and the procedure for making a scarf:

First of all, a scarf is a diagonal or sloped joint used to marry two pieces of stock together to make a larger or longer part. In boat building we use them for gunwales and side and bottom planking and in aircraft for stringers and leading or trailing edge stock and spars and spar caps.

Second, its best if possible to make the scarf joint fall on or cross over a structural framing member such as a rib or bulkhead.

Third, if possible and without making the scarf too long, have the ends of the joint pass over at least two structural members.

Fourth, its best not to have the upper and lower spar caps scarf-jointed at the same location so the lower cap can be scarfed on the inner panel. I would chose this method, greater distance to the first scarf on the upper, shorter distance to the first scarf on the bottom with good reason - most failures occur in compression and in the case of the wing, this would be the upper surface. Also, the greatest shear loads on a wing panel occur in the first 10% of the span and diminish geometrically further away from the junction of the wing with the fuselage.

In the case of Mike's 1-23, the rib spacing is less than three inches and the stock he is working with is 3/16" x 1/2" Douglas fir. With the 36" long parts, Mike can make the first scarf between ribs 5 and 6 which are the second and third ribs of the outer tapered wing panel. Using a slope of about 5 degrees for the joint will enable him to pass by both of these ribs by about 3/4" to 1" which will yield the highest strength.

Arranging the scarf joints as pointed out above, will yield the highest margin of safety. In addition, make the joints on upper and lower surfaces fall at least three of four rib bays away from each other so loads can be distributed well away from any inherent weakness in the spar caps caused by scarfing.

Now all of this said, it should be remembered that if one uses a high quality epoxy or Titebond II^TM to cement the scarf joints following the procedures above and making the jointed surfaces as accurate as possible, no problems with these joints will ever be experienced. The joints will be strengthened further by the use of shear webs against and across the edges of the joints and the balsa sheeting applied on the wide or flat surfaces of the joints. In all cases, make sure you have good wetting of the joints with the adhesive chosen, and a good system for clamping the joints till cured to achieve the best quality bonds.

For cutting the joints, mark one piece with the slope or angle of the scarf and then stack the two parts to be joined one over the other, end-to-end and cut both parts through at the same time, making sure to keep your razor saw in perfect 90 degree or vertical alignment perpendicular to the working surfaces. Test fit the joints once cut and if necessary, align the two scarfs together mated against their flat sides and run a small hand plane over the joints to square and true them.

After testing the fit to your satisfaction, be sure to wet both surfaces with just enough cement to make sure there is at least a little squeeze out under clamping pressure but not so much that the parts will slide against one another. To prevent this, before cementing place waxed paper on the edge of the workbench and clamp two stop blocks on the bench positioned at each end of the parts to keep the clamping pressure from moving them away from each other longitudinally. Have at least two small clamps prepared to clamp the joint once aligned in your shop-made "jig". To make sure that the fine tapered ends of the joint receive as much clamping pressure as the center section, use two small cauls or blocks of wood between the clamps and each part to spread the force throughout the jointed surfaces. If necessary, place another piece of waxed paper on top of the joint and another clamp to hold down-pressure keeping the joint tight to the workbench and the two parts in face alignment while the glue cures.

Finally, after the cement has cured to initial hardness, remove the three clamps at the joint and using a scraper or razor blade, remove as much of the excess cement from both sides before it reaches full cure and final hardness. Then set the part aside to cure for another few hours before cutting to final length or making the next scarf joint, if required.

Mike will illustrate these proceedures in his build log.

The Plans Page

PLAN DESCRIPTION
Note plans may be previewed at the URL http://www.tmrcsailplanes.com/images and then finding the appropriate JPEG file as listed in the descriptions below sorted in alphabetical order. If you don't find what you are looking for, please ask us!

asw15_98.jpg
Schleicher ASW 15 1:6 scale
VERY SCALE 1 SHEET PLAN FOR ALL WOOD SAILPLANE!
1 sheet 36" x 52"
Specs: 98" span, 2 channel or add ailerons and spoilers for full house control.
$7.95 US

afiasw-17_132.jpg
Schleicher ASW 17 1:5 scale
VERY SCALE 1 SHEET PLAN FOR WOOD SAILPLANE WITH GLASS FUSELAGE!
1 sheet 36" x 70"
Specs: 132" span, 2 channel or add ailerons and spoilers for full house control.
$9.95 US

atj3cub70.jpg
Piper J-3 Cub 1:6 scale Tail Dragger
VERY SCALE 1955 VINTAGE 1 sheet PLAN!
1 sheet 35" x 45"
Specs: 70" span, .19 to .40 engines (plans show Fox .19) or large electric conversion.
$7.95 US

berkamericanace36.jpg
Berkeley American Ace Old Timer
1950's VINTAGE 1 sheet PLAN!
1 sheet 12" x 24"
Specs: 36" span, .010 or electric conversion.
$2.95 US

berkcessna180_36.jpg
Cessna 180 1:12 scale Classic 50s taildragger - SWEET SQUARE TAIL!
1 sheet 35" x 45" with instructions and full patterns.
Specs: 36" span, .035 to .049 freeflight or .049 to .099 control line engines or rubber or electric conversion.
$7.95 US

berksa130_40.jpg
Schweizer SA 1-30 1:12 scale Standoff Scale American Motor Glider - VERY COOL!
1 sheet 24" x 36" with instructions
Specs: 40" span, .020 to .099 size engines or easy electric conversion.
$5.95 US

berkstinsonvoy150_34.jpg
Stinson Voyager 150 1:12 scale Classic 40s taildragger - SWEET!
1 sheet 35" x 45" with instructions
Specs: 33" span, .049 to .099 engines or rubber or electric conversion.
$7.95 US

captaylorcraft30.jpg
Taylorcraft 1:12 scale GREAT FIRST SCALE TRAINER!
1 sheet 24" x 36" with instructions
Specs: 30" span, rubber power, .049 engine or electric conversion.
$5.95 US

comaeroncachief54.jpg
Aeronca Chief Tail Dragger - 1:8 SCALE AND A NICE SCALE RENDITION OF THE 40s CLASSIC IN PERFECT SIZE!
1 sheet 25" x 35"
Specs: 54" span, .rubber power would be good with .049 or electric conversion.
$6.95 US
LASER CUT KITS AVAILABLE!

comaeroncak54.jpg
Aeronca K at 1:8! A CLASSIC 30'S TAIL DRAGGER THAT YOU JUST DONT FIND OLD KITS OF.
1 sheet 23" x 34" with instructions, unbelievable details for scale engine, instrument, seats... wow!.
Specs: 54" span, rubber power would be good with .049 or electric conversion.
$6.95 US
LASER CUT KITS AVAILABLE!

comaeroncak25.jpg
Aeronca K with Floats A CLASSIC 30'S TAIL DRAGGER WITH VENTRAL FIN AND FLOATS.
1 sheet 23" x 24" with instructions, decal patterns and engine detail drawings.
Specs: 25" span, rubber power would be good for small electric conversion.
$4.95 US

comc-37_20.jpg
Cessna C-37 THE VERY VINTAGE ROUND ENGINE CESSNA WITH ROUND TAIL AND WINGS.
1 sheet 23" x 24" with instructions.
Specs: 20" span, rubber power would be good for small electric conversion.
$4.95 US

comjennyJN4_24.jpg
Curtiss JN-4 Jenny scale WWI biplane trainer with at a very sweet size for indoor RC!
1 sheet 17" x 22"
Specs: 24" span, rubber power or small electric and micro RC conversion.
$4.95 US

comsupercruiser40.jpg
Piper Super Cruiser UNUSUSAL 40" SPAN NOT OFFERED AFTER THE 1950s BUILDS JUST LIKE THE FAMILIAR 54 INCHERS!
1 sheet 23" x 34"
Specs: 40" span, rubber power or small electric and micro RC conversion.
$6.95 US
LASER CUT KITS AVAILABLE!

comj5cub26.jpg
Piper J5 Cub Cruiser The next generation Cub with, all the familiar features!
1 sheet 22" x 34"
Specs: 26 1/2" span, rubber power or small electric and micro RC conversion.
$5.95 US

comtaylorcraft21.jpg
Taylorcraft Tail Dragger at indoor scale and a very clean and simple build!
1 sheet 17" x 22"
Specs: 21" span, rubber power or small electric and micro RC conversion.
$4.95 US

comtaylorcraft54.jpg
Taylorcraft Tail Dragger - 1:8 SCALE AND A NICE SCALE RENDITION OF THE 40s CLASSIC IN PERFECT SIZE!
1 sheet 35" x 35"
Specs: 54" span, .rubber power would be good with .049 or electric conversion.
$6.95 US
LASER CUT KITS AVAILABLE!

comtaylorcub18.jpg
Taylor Cub ANOTHER CLASSIC LATE 30s TAIL DRAGGER FOR THOSE WHO WANT SOMETHING DIFFERENT.
1 sheet 23" x 24"
Specs: 18" span, .rubber power would be good for small electric conversion.
$4.95 US

cubblueprint.jpg
Factory Blue print consisting of complete 3 views and structural details for the Classic Piper Cub suitable for enlargement for scratch building or display.
$10.95 US

jetcessna170_36.jpg
Cessna 170 Accurate scale 1:12 VERY HIGH QUALITY PLANS. This is the Cessna with the cute round tail!
1 sheet 36" x 46" with detailed instructions.
Specs: 36" span, .020 to .049 size engines.
$7.95 US

eteaglet.jpg
Eaglet The little Rubber Duration model from Jetco with Vee Tail Option, FEELING COMPETITIVE?
1 sheet 17" x 22" with instructions
Specs: 18" span, 49 sq. in. 1 oz. flying weight. 2 minute flights possible.
$3.95 US

jetrearwinspeed38_1.jpg
jetrearwinspeed38_2.jpg
jetrearwinspeed38_3.jpg
Rearwin Speedster The classic three in one plan for freeflight, controline or RC in very accurate 1:12 scale. Another classic mid-thirties design taildragger with very unique styling!
3 sheets 36" x 46" with instructions and all patterns.
Specs: 38" span, 26-3/4" length, 16 oz. (RC) suitable for .049 to .19 size engines.
$15.95 US

jetrog.jpg
ROG Classic 50s Rubber-powered "Rise Off Ground" tissue covered model with free-wheeling landing gear.
1 sheet 17" x 22" with instructions
Specs: 18" span.
$3.95 US

krekmissdara1.jpg
krekmissdara2.jpg
Miss Dara Quarter Midget Racer An extremely high quality hand drawn and unpublished plan!
2 sheets 24" x 36"
Specs: 38" span, .15 size engine.
$9.95 US

piperl4grasshop72_1.jpg
piperl4grasshop72_2.jpg
Piper L-4 Grasshopper 1:6 scale GREAT FIRST SCALE TRAINER!
2 sheets 30" x 48" with instructions
Specs: 72" span, .19 to .40 engines or electric conversion.
$13.95 US

pipertg8.jpg
Piper TG-8 Training Glider Factory 3-view print from Piper circa 1940s.
1 sheet 12" x 24".
$1.95 US

staeroncac3_36_1.jpg
staeroncac3_36_2.jpg
Aeronca C3 GREAT FLYING AND VERY VINTAGE FIRST BUILT-UP MODEL!
2 sheets 26" x 22" with complete instructions
Specs: 36" span for rubber or .020 engine control line or vintage RC.
$8.95 US

staeroncachamp21.jpg
Aeronca Champion Another classic post war taildragger for rubber power, built-up sheet balsa design!
1 sheet 23" x 25" with instructions
Specs: 21" span, rubber or small electric conversion for micro RC.
$4.95 US

stcessna170_21.jpg
Cessna 170 This classic taildragger for rubber power, built-up sheet balsa design.
1 sheet 23" x 25" with instructions
Specs: 21" span, rubber or small electric conversion for micro RC.
$4.95 US

stcessna180_45_1.jpg
stcessna180_45_2.jpg
Cessna 180 1:8.7 scale The classic 60's taildragger from Cessna with the square tail!
2 sheets 36" x 46" with instructions.
Specs: 45" span, 30" length for .09 to .15 power, freeflight, vintage or micro RC. (tube radio shown)
$13.95 US

stcirrus87_1.jpg
stcirrus87_2.jpg
Schemp Hirth Cirrus 1:8 scale The classic 60's all fiberglass sailplanes from Germany in true scale!
2 sheets 30" x 43" with instructions and patterns
Specs: 87-5/16" span, freeflight, display or micro RC.
$9.95 US
LASER CUT KITS AVAILABLE!

stcorsair36_1.jpg
stcorsair36_2.jpg
Chance-Vought F4U-1A Corsair Classic World War II inverted gull wing fighter!
2 sheets 25" x 38" with instructions
Specs: 36" span, .049 to .051 size engines or electric conversion.
GREAT 3 VIEWS INCLUDED WITH SCALE DETAILS FOR MARKINGS AND ARMAMENT!
$9.95 US

stcurtissjenny32_1.jpg
stcurtissjenny32_2.jpg
Curtiss JN-4 Jenny 1:16 true scale WWI trainer with complete 3-veiws and incredible detail!
2 sheets 24" x 36" with instructions and patterns
Specs: 32-3/4" span, freeflight, display or micro RC.
$9.95 US

stdiamant74_1.jpg
stdiamant74_2.jpg
Diamant 1:8.73 scale Another of the European early fiberglass designs in true scale!
2 sheets 24" x 36" with instructions and patterns
Specs: 74" span, 260" area, freeflight, display or micro RC.
$9.95 US

stf51mustang66_1.jpg
stf51mustang66_2.jpg
North American P-51D Mustang Great flying scale model of WWII long range support and attack fighter.
2 sheets 35" x 45" with full instructions
Specs: 66" span for .35 to .60 size engines and full house RC.
$13.95 US

stfledgling56_1.jpg
stfledgling56_2.jpg
Fledgling Tricycle Gear - EXCELLENT FLYING TRAINER!
2 sheets 28" x 46" with instructions
Specs: 56" span, 545 sq.in., .23 to .40 or electric 4-6 channel park flier.
$11.95 US
LASER CUT KITS AVAILABLE!

stj3cub30_1.jpg
stj3cub30_2.jpg
Piper J-3 Cub 1:14 scale The original Cub in a great beginner's tissue covered fuse design with 3 views!
2 sheets 23" x 32" with instructions
Specs 30" span for rubber or .020 engine control line or vintage RC.
$9.95 US

stluscombesedan21.jpg
Luscombe Sedan Another classic post war taildragger for rubber power, built-up sheet balsa design.
1 sheet 23" x 25" with instructions
Specs: 21" span, rubber or small electric conversion for micro RC.
$4.95 US

stminifledgling40_1.jpg
stminifledgling40_2.jpg
Mini Fledgling Tail Dragger - CONSTANT CHORD, SIMPLE-TO-BUILD TRAINER!
2 sheets 23" x 35" with instructions
Specs: 40" span, .049 to .051 or electric 4-6 channel park flier.
$9.95 US
LASER CUT KITS AVAILABLE!

stmonocoupe64_1.jpg
stmonocoupe64_2.jpg
Monocoupe THE 30's CLASSIC WITH THE ROUND COWL AND RADIAL ENGINE!
2 sheets 35" x 45"
Specs: 64" span, class A, B, or C engines
Designed specifically for radio control, a great vintage RC project!
$13.95 US

stpa12cub36_1.jpg
stpa12cub36_2.jpg
Piper PA-12 Cub Cruiser This is the classic upgraded Cub in a perfect 1:12 scale for parkflyer and backyard size with scale-sized vertical and horizontal tails, with full factory three views included on the plan sheets.
2 sheets 23" x 35" with instructions.
Specs: 36" span, .020 or small electric conversion.
$9.95 US

stpa18cub72_1.jpg
stpa18cub72_2.jpg
Piper PA-12 Cub Cruiser Another great Cub in a perfect 1:6 scale for towing your favorite 1-3 meter sailplane when sufficiently powered or just decking out with all the scale details and sure to turn heads.
2 sheets 35" x 45" with instructions.
Specs: 72" span, K & B .45 shown or great for larger electric conversion.
$13.95 US

stpa22tripacer58_1.jpg
stpa22tripacer58_2.jpg
Piper PA-22 Tri-Pacer 1:6.9 scale GREAT FIRST SCALE TRAINER!
2 sheets 35" x 45" with instructions
Specs: 58 3/4" span, .19 to .40 engines or electric conversion.
$13.99 US

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Stearman PT-17 Kaydet Trainer The vintage between the wars trainer, crop duster and airshow biplane!
4 sheets 35" x 45" with instructions and factory 3 views
Specs: 64 1/2" span, .56 to .65 size engines.
$19.99 US

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Fairchild PT-19 Cornell Trainer The classic low wing primary trainer between the wars!
2 sheets 35" x 45" with instructions
Specs: 48" span, .15 to .35 size engines or electric conversion.
$13.99 US

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Royal Coachman Tricycle Gear - CONSTANT CHORD SIMPLE-TO-BUILD TRAINER!
1 sheet 36" x 45" with instructions
Specs: 41 1/2" span, .09 to .15 engines or electric 4-6 channel.
$7.95 US

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MACHINE CUT HULL AND MAST KITS AVAILABLE!
$7.95 US

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Schweizer SGS 1-26D 1:6.7 scale THE CLASSIC ONE DESIGN!
2 sheets 36" x 45"
Specs: 70" span, 500 sq. in. wing area, 10:1 aspect, 3 channel to full house RC.
A GREAT SUBJECT TO ENLARGE TO 1/4 SCALE - UNIQUE!
$13.95 US
LASER CUT KITS AVAILABLE!

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Schweizer SGS 1-34 1:6 scale
2 sheets 29" x 51"
Specs: 98 1/2" span, 615 sq. in. wing area, 16:1 aspect, 3 channel to full house RC.
A GREAT SUBJECT TO ENLARGE TO 1/4 SCALE - UNIQUE!
$13.95 US

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Schweizer SGS 2-32 1:16 scale The 60's multi-seat record setter with the jet-like tails and canopy!
2 sheets 18" x 24"
Specs: 42 3/4" span, 135 sq. in. wing area, 18:1 aspect, freeflight, display or micro RC.
WE OFFER THIS ONE IN 1/6 SCALE LASER CUT PARTS AND ORIGINAL PLANS FOR 114" SPAN
$8.95 US

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MACHINE CUT HULL AND MAST KITS AVAILABLE!
$3.95 US

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MACHINE CUT HULL AND MAST KITS AVAILABLE!
$5.95 US

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Stinson SR-8 Reliant 1:16 scale Classic Golden Age Gullwing - SWEET!
2 sheets 35" x 45" with instructions
Specs: 31 3/8" span, .09 to .15 size engines or electric conversion.
$8.95 US

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Taylorcraft Another classic post war taildragger for rubber power, built-up sheet balsa design.
1 sheet 23" x 25" with instructions
Specs: 21" span, rubber or small electric conversion for micro RC.
$4.95 US

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Piper PA-17 Vagabond 1:12 scale Tail Dragger - CLASSIC 40s AIRCRAFT!
2 sheets 23" x 35" with instructions
Specs 33" span, rubber power, .049 size engine or great size for small electric.
$9.95 US

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Thermic 100 Classic 40s Towline Glider, Maybe the original pod-and-boom glider!
2 sheets 36" x 46" with instructions.
Specs: 100" span, towline/handlaunch simple rc and or electric conversion.
$13.95 US

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Thermic 100 Postwar The later redesign with with fully box framed fuselage and new tail.
1 sheet 36" x 46" with instructions
Specs: 100" span, towline/handlaunch simple rc and or electric conversion.
$7.95 US

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Thermic 50, THE ORIGINAL 1940's JASCO THERMIC 50 WITH DUAL SPAR WING AND CABIN FUSELAGE, A BEAUTY!
1 sheet 27" x 34" with instructions
Specs: 50" span, simple rc or electric conversion.
$5.95 US
LASER CUT KITS AVAILABLE!

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Thermic 50-X VERY EARLY JASCO POD AND BOOM FREEFLIGHT DESIGN WITH LIFTING STAB, SAM QUALIFIED!
1 sheet 27" x 34" with VERY complete instructions
Specs: 50" span, 22" length, 198 in.2, all up weight 4-5 oz. (freeflight).
Very beautifully drawn plans. Unlike the other two Thermic 50 designs, this one uses half ribs at the wing leading edge spaced between the full ribs and a much stronger wing with double spars and the more classic swept elliptical tail.
$5.95 US
LASER CUT KITS AVAILABLE!

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Thermic 70 LIKE AN ENLARGED VERSION OF THE JASCO THERMIC 50 WITH CABIN FUSELAGE, VERY LIKELY THE INSPIRATION FOR THE BIRD OF TIME FROM DAVE THORNBURG. SAM QUALIFIED CLASS E!
1 sheet 36" x 48" with VERY complete instructions
Specs: 70" span, 34-3/4" length, all up weight 12 oz. (freeflight).
Typical high quality Jasco plans drawings show all parts required for the scratch builder. This design uses the same wing and stab planforms as the 50-X and 72, dual spars but lacking the half ribs at LE.
$7.95 US
LASER CUT KITS AVAILABLE!

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Jasco Floater THE EARLY JASCO FULL CABIN FUSELAGE AND STRAIGHT/TAPERED WING PLANFORM AND CONSTANT CHORD STAB. SAM QUALIFIED!
1 sheet 36" x 44" with VERY complete instructions
Specs: 72" span, 37-5/8" length, 476 in.2, all up weight 14.25 oz. (freeflight).
Very beautifully drawn plans by Frank Zaic. Very much like the Thermic 70 - an enlarged 50 - in the fuselage and tail but more modern sailplane wing uses constant center/tapered outboard panels with polyhedral, high aspect constant chord stabilizer. All parts are shown on plans for the scratch-builder.
$7.95 US

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Jasco Floater THE LATER FLOATER WITH THINNED FUSELAGE AND REDESIGNED TAILS AND DETHERMALIZER DETAILS. SAM QUALIFIED!
1 sheet 36" x 44" with VERY complete instructions
Specs: 70" span, 36-5/8 " length, 476 in.2, all up weight approximately 15 oz. (freeflight).
Using the same wing as the1946 Floater, this one dispenses with the half ribs, has a thinned fuselage and tails more like those of the later Jetco designs.
$7.95 US

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Thermic 72 WITH THE THERMIC 50-X, THE EARLY 40's POD AND BOOM SO OFTEN COPIED. SAM QUALIFIED!
1 sheet 36" x 48" with VERY complete instructions
Specs: 72" span, 32-3/4" length, 410 in.2, all up weight 12-14 oz. (freeflight).
Very beautifully drawn plans. Unlike the latter Jetco Thermic 72 design, this one is more similar to the Thermic 50-X with much stronger wing with double spars and a more elegant pod design and the more classic swept elliptical tail.
$7.95 US
LASER CUT KITS AVAILABLE!

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Thermic 30 A VERY OBSCURE PLAN FROM EARLY JASCO YEARS DRAWING BY FRANK ZAIC!
1 sheet 20" x 20" with complete instructions and patterns; Specs: 30" span for polyhedral set-up.
$2.95 USD

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Thermic 20 version 1. VERY EARLY AND OBSCURE FRANK ZAIC PLAN FROM THE EARLY JASCO YEARS BY FRANK ZAIC!
1 sheet 12" x 10" with complete instructions and patterns; Specs: 20" span for dihedral set-up.
$2.95 USD

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Thermic 20 version 2. VERY EARLY AND OBSCURE FRANK ZAIC PLAN FROM THE EARLY JASCO YEARS BY FRANK ZAIC!
1 sheet 12" x 10" with complete instructions and patterns; Specs: 20" span for dihedral set-up.
$2.95 USD

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Jasco Thermic C Classic 40s Towline Glider, GREAT VINTAGE STYLING!
1 sheet 23" x 26" with instructions; Specs: 36" span, towline/handlaunch simple rc and or electric conversion.
$4.95 US
LASER CUT KITS AVAILABLE!

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Jasco Sailwing 50 a very unique 40s Towline Glider, Ready for a challenge
1 sheet 28" x 34" with instructions; Specs: 50" span, towline/handlaunch more complex rc conversion.
$5.95 US
LASER CUT KITS AVAILABLE!

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Jasco Trooper Classic 40s Towline Glider, SQUARE WINGS AS THE LATER JETCO BUT SET UP FOR DIHEDRAL ONLY!
1 sheet 22" x 26" with instructions
Specs: 36" span, towline/handlaunch simple rc.
$4.95 US
LASER CUT KITS AVAILABLE!

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Thermic 18 ONE OF THE HANDLAUNCH GLIDERS THAT STARTED SO MANY KIDS CUTTING BALSA!
1 sheet 8" x 10" with complete instructions and patterns; Specs: 18" span for dihedral or polyhedral set-up.
$2.95 USD
LASER CUT KITS AVAILABLE!

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Thermic B ONE OF THE HANDLAUNCH GLIDERS THAT STARTED SO MANY KIDS CUTTING BALSA!
1 sheet 12" x 18" with complete instructions and patterns; Specs: 20" span for dihedral or polyhedral set-up.
$3.95 US
LASER CUT KITS AVAILABLE!

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Thermic 20 ONE OF THE HANDLAUNCH GLIDERS THAT STARTED SO MANY KIDS CUTTING BALSA!
1 sheet 12" x 18" with complete instructions and patterns; Specs: 17" span dihedral wing glider.
$3.95 US
LASER CUT KITS AVAILABLE!

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Jetco Thermic C Classic 50s Towline Glider, PERFECT FIRST BUILT UP MODEL!
1 sheet 23" x 26" with instructions; Specs: 36" span, towline/handlaunch simple rc and or electric conversion.
$4.95 US

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Jetco Trooper Classic 50s Towline Glider, SQUARE WING, GREAT FIRST MODEL USES POLYHEDRAL UNLIKE THE EARLIER JASCO!
1 sheet 22" x 26" with instructions
Specs: 30" span, towline/handlaunch simple rc and or electric conversion.
$4.95 US

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Thermic 36 Full cabin fuselage towline glider in the classic Jetco Thermic 50 tradition!
1 sheets 22" x 28" with instructions.
Specs: 36" span, towline/handlaunch simple rc and or electric conversion.
$4.95 US

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Thermic 36 Solid balsa construction pod and boom hand launch glider in the tradition of the Thermic B, 18, and 20 on a large scale!
1 sheets 9" x 15" with instructions.
Specs: 36" span, handlaunch.
$2.95 US

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Thermic 50 RC, THERMIC 50 WITH BOX FUSELAGE AND ENGINE POD FOR .010 OR TOWLINE RC!
1 sheet 27" x 34" with instructions
Specs: 47" span, .010 size motor on pod, simple electric conversion.
$5.95 US

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Thermic 50, THE LATER 1950's JETCO THERMIC 50 WITH CABIN FUSELAGE AND NO SPARS, A BEAUTY!
1 sheet 27" x 34" with instructions
Specs: 47" span, simple rc or electric conversion.
$5.95 US

A shipping charge of $5 US will be added to orders . Please add $5 US for shipping rolled in a hard tube and for overseas deliveries folded flat.

PayPal us direct to bolt55@vsente.com the indicated price plus $5.00 USD shipping for continental US delivery add $1 for each additional plan set ordered for the same package and email us for overseas delivery price quote. Please be sure to list the plans using the same names used in the jpeg preview files next to each plan description.

Scale Details From the Desktop

Flying Models will be publishing my article on how to create scale details for your glider or sailplane model using readily available drawing tools such as Corel^TM and Illustrator^TM in their August issue. A couple of paragraphs from the article here and we will do a full reprint after it has been published.

One of the most satisfying parts of building scale flying models is the addition of details that make your completed model more realistic, and of course more noticed by fellow modelers for the extra effort and originality that these details represent. One of the easiest and most satisfying of these to produce, believe it or not, is a scale instrument panel, a detail that is sure to be noticed by everyone at the flying field.

Since I began building scale models, I always remembered the instrument panels that were printed on the plans and I always cut them out and applied them to the instrument panel bulkhead before I started doping on the tissue or ironing on the covering. When I began designing scale U.S. sailplane models for the TMRC kit line (www.tmrcsailplanes.com), I immediately searched for photos of the correct panels so I could draft them and include them at proper scale on the plan sheet. It wasn’t long before I looked at ways of using the resources already at hand to produce even better looking graphics and soon, to produce the panels themselves.

The full scale SGS 1-23 instrument panel photo courtesy of Gerry Daugherty

First, all panels no matter how complex, are based upon some simple building blocks and many of these are standardized. Second, in civil and commercial aviation and in many military applications, navigational instruments are standardized in just a few diameters and sizes. Once you’ve drawn one altimeter or compass for example from a classic 50s or 60s single engine prop plane, you’ll find that the same instrument will fit in the circular panel cutout in just about every other aircraft of that type and era. There have been only so many major instrument manufacturers over the years and standard instrument faces were 3 1/8 inches and 2 ¼ inches in diameter. Radios too were manufactured to fit standard openings and toggle switches were about the same throughout the industry. All of this helps keep it simple for the model panel designer and builder.

Panel shapes can often be found by doing a simple search of the internet, calling the manufacturer of the full size craft, or visiting the website of one of the panel design companies throughout the U.S. and in our resources list. Simply scale it to the new size needed and cut and paste it into your next project drawing. Some laser cutters may even be willing to send you a list or PDF file of available instrument faces that they have drawn and you can have them send you files for the instruments you need or you may simply need to provide a photo of the panel you want to build and a vertical and horizontal overall dimension for the cutter to scale the outline and drop in the instruments to match in a digital format for cutting and provide a quote for the parts.

The digital elements needed to produce a scale instrument panel kit are shown above taken from the Adobe Illustrator^TM file. If you click on the image you may be able to see the drawn panel, frames, bezels and screw detais.

Below is the assembled, painted and completed panel by Jim Hoffer of New Mexico and placed in his one fight scale SGS 1-23D model.

Sources:
www.panelplanner.com
www.epaneldesigner.com
www.airliners.net

I Found My Sailplane Pilot's Log Book

I was getting a book down from the shelf in our living room last week when I spotted a log book tucked in next to some other books and the Soaring Final Exam from the SSA. Wow, I didn't remember even getting these books and quickly opened it up to discover that I had filled out the first page with my name and address in 1990 in Lancaster CA.

I flipped the page and there were two flights logged and signed off:

1-27-1990    Flight 1    SGS 2-33    N2905H    Aerotow    3000ft release    Skylark North    16 minutes
Preflight nose attitude for minimum sink and best glide. 90 & 360 deg turns

1-27-1990    Flight 2    SGS 2-33    N2905H    Aerotow    3000ft release    Skylark North    16 minutes
Airspeed control exercises, 360 deg turns, pattern & landing (to touchdown)

Now its odd I don't even remember flying the 2-33 but I do remember that our trip to Skylark North was the first day trip I took with my girlfriend Julie, now my wife with two kids. Maybe that explains the loss of memory! I do recall going up in the Blanik but have no recollection of the 2-33 flights. Maybe the instructor miswrote that detail..... but now I'm 32 minutes closer to soloing than I expected!

Sailplane Modeling in the 21st Century

The following article is reprinted in part from SOARING, the monthly publication of The Soaring Society of America (SSA) from their April 2009 Issue.

A Passion for Scale Soaring

When I was approached by the editor of SOARING to write an article about radio control sailplane modeling, I was honored to have been given what I considered to be a wonderful opportunity. I jumped at the chance and later in an email conversation with Dr. Gary Fogel, an avid soaring enthusiast and radio control sailplane pilot, I learned the last time SOARING magazine devoted pages to modeling was in 1968 when the subject was explored by Dale Willoughby.

Modeling has changed a lot since then and, as in full scale, composite structures have become the norm in both thermal duration as well as competition F3B, F3J and handlaunch as well as scale models. In fact there has been a proliferation of all-molded glass reinforced plastic (GRP) radio control models. Many of these have been produced in Europe for three decades with Germany and the Czech Republic leading the way in quality molded glass and carbon fiber sailplanes.

In the last several years, EPP (Expanded PolyPropylene) and ElaporTM foam are now being employed to produce nearly indestructible molded models as well. Originating with modelers experimenting with varieties of materials, these “foamies” offer extreme durability while being able to hold scale lines and proportions offering flyers the benefit of less than perfect landings in harsh environments without major damage. This also makes them perfect for training. Manufacturers are able to create expensive tooling to mold these materials producing precision parts that assemble with ease and a fair degree of technical advancement while offsetting high costs of development with large sales volumes. Home builders and garage shop manufacturers may easily band saw and shape one-off models with these materials as well which are now available from many suppliers.

I would contend that beyond molding, the most important change in recent time has been the advent of computer-controlled laser systems in production of wooden parts (laser cutting machines commonly cut balsa wood, plywood, carbon fiber plate, and even some non-ferrous metals and plastic sheeting). The laser has been adopted wholesale by model manufactures, driven by consumers who have come to demand the high quality parts kits they may produce. Providing precisely interlocking notches and tabs as well as shapes not possible or feasible with knife dies, lasers have dramatically improved the quality and number of parts that may effectively kitted, including notched and interlocking trailing edges, leading edges and spars.

What this has meant for modelers is that one may be jigging parts together over plans within minutes of opening the box. Parts release easily from their carrier sheets, and with their self-jigging and interlocking tabs, slots and notches, assemble more quickly and require less clamping. Utilizing the laser to advantage can produce parts with more contact surfaces between parts providing stronger glue bonds, more square, parallel and fair assemblies and surfaces requiring less final preparation for covering - in the end improved structural integrity and quality of models with no increase in difficulty for the builder.

In this sense, the laser and computer-controlled cutting technologies have revolutionized model building to the point that it has created a resurgence of the hobby by those who know how and love to craft their own models from parts. One might say the laser has put the joy back into building. Even scratch-builders are drafting parts for projects with readily available software such as Corel, Illustrator, AutoCad and or TurboCAD and sending them out to commercial cutters to save time in development of finished models or prototypes.

Another result of these technologies and the experimentation of modelers is that sheet foam originally used to make trays for displaying and storing food in grocery stores in now available in different thicknesses and compositions which can be cut and kitted similarly to wood products. There are many small-to-large firms doing just this with elegantly designed parkflyers (a new word coined in the market to describe mostly small and electric powered aircraft) which are robust and easy to build, and may be flown indoors or out, without much fear of damage to property or spectators. These sheet-foam structures may look like wooden models of the past in the construction method they employ with slab and boxed fuselages and flat wings and supported by flying wires or struts to gain rigidity.

Changes in world markets have brought a proliferation of almost-ready-to-fly model aircraft (ARFs), driven by the importing of mass-produced models from China and this has changed the hobby even more. The new low-cost ARFS have allowed model aviation to be enjoyed by anyone with a modest amount of money and no investment to learn the skills of building or time required to construct a model. The mostly balsa and plywood models from China are increasing in quality every year as manufacturers strive to improve the techniques and technologies of their overseas facilities to provide the quality demanded by fliers.

But for those who have not adopted ARFs as a way to enjoy the hobby, the reduction in cost of CNC technologies has brought hundreds of small business operators into the kit manufacturing arena as well. Where kit manufacturing was once dominated by ten or more large corporate or family owned and operated businesses, we now see literally scores of small, highly creative and specialized manufacturers producing a broad range of model aircraft subjects. The author is one of those with a business model based upon the need for high quality and historically accurate scale representations of U.S. sailplanes. This is a niche that was untouched until five years ago when the decision was made to take up modeling once again as a business after a long hiatus from flying.

All of these advances have opened the market to many more consumers, allowing investment in improvements in electronics across a broad spectrum. Now radio manufacturers such as Spektrum, JR Radio and Futaba are offering spread spectrum radios using Digital Spectrum Modulation (DSM) which allows multiple users to fly at the same time and location without regard to frequency. Prior to this technology, the last major change in radios was in the 1980s with the introduction of Pulse Code Modulation (PCM). PCM replaced the old analog signals with digital signals, offering a cleaner, more robust signal to the receiver. The introduction of PCM greatly reduced signal interference, which could lead to servo chatter or unwanted control movements.

With the introduction of products applying spread spectrum to the modeling industry little over a year ago, radio control is now closed to any type of interference. A Globally Unique Identification Code is assigned to each transmitter in manufacture with the receiver being programmed to identify that unique code and bind together, essentially locking out all others in the process within a few seconds of energizing the system.

As this occurs, the signal is spread out over a wide band before being processed by the receiver where it is essentially “reassembled”, further increasing security. This process is so fast that servo movement and model response are instantaneous and direct. What this means is model fliers may fly with a unique frequency along side hundreds of others without interference from those operators. There are no crystals so frequency management at the site is unnecessary. The system utilizes shorter transmitter antennas and receiver antennas are designed so they are completely contained and protected inside the aircraft.

The technology has been available for a long time in communications. only now has making its way to the modeling public. More information on the history, development, commercial licensing and permitting of spread spectrum technologies may be found at http://en.wiki.org/wiki/Spread_spectrum. The concept and original patents for these developments date back to the 1890s when Nickola Tesla recognized the need for secure signal transmission and processing to prevent interference in any way.

Batteries and servos have improved dramatically as well, becoming less expensive and primarily more reliable and powerful. Technology is evolving rapidly as new materials and manufacturing processes continually increase battery output while decreasing weight of storage devices. All systems now incorporate rechargeable batteries and offer choices of primarily LiPoly (lithium polymer) or NiMH (Nickel Hydride) which offer battery performance unparalleled only five years ago.

In turn, a new market has emerged in the manufacturing of smart chargers and, powerful and lightweight electric motors for model aircraft of any size. Smart chargers are able to peak storage and power output while offering prolonged battery life. Electronic speed controllers (ESC) used in the battery-receiver circuits onboard models throttle these compact, lightweight motors and have similarly advanced, offering consumers more reliability and features not available only five years ago being led by U.S. manufacturer Castle Creations in Olathe, Kansas http://www.castlecreations.com.

And there’s more! Specialty devices using GPS (Global Positioning System) now capture and store flight data with the ability to transmit back and display on the ground. Not much larger than a pack of gum, these devices are easily incorporated into airframes as small as two meters in span. These products have the ability to monitor onboard battery condition as well, offering reliability and fail-safe mechanisms for expensive aircraft. Although varios have been available to modelers, technology  has advanced as well and now several products are available that will instantly communicate to the pilot whether they are in lift or sink offering bundled features utilizing GPS.

The global application of many federally funded technologies originally employed by communications and military users, has enabled transfer to the marketplace quickly at relatively low investment by entrepreneurs. Many have changed the way we live allowing us to employ technology in new ways in our everyday lives. We have become so astute astute to technology in our homes that it’s natural we have applied these to our love of aviation enabling us to enjoy the hobby in new and exciting ways.

In scale modeling and of interest to modelers of aircraft, several companies now produce accessories and specialty products to customize and personalize our models. These include very high quality graphics including decals and trim produced by Callie Graphics in Edgewood, NM and life-like customizable full-body pilot figures created by Premier Pilots in San Diego, CA.

Spurred on by her father Stan at Hobbies ‘N Stuff in Albuquerque, Callie Johnson (http://www.callie-graphics.com) produces a variety of standard and custom decals in vinyl which are easily applied to models of any kind. Digital technologies again have streamlined and simplified the process whereby anyone with access to a digital camera or computer with scanner and illustration software may either produce or provide information allowing the duplication of full-scale markings and insignia which may be replicated cost-effectively in small lots. Utilizing CNC film cutters, this same technique is used by sign shops throughout the world who may even employ adhesive films or frisket products producing masks that are easy to apply, offer crisp sharp edges and work with aerosol paints to offering excellent results for professionals and hobbyists alike.

While flying radio control Schweizer 1-26s at Torrey Pines, Ren DiLeo (http://www.premierpilots.net) recognized the need for highly detailed, lightweight pilots at quarter scale to fill the void inside the cockpit and canopy of his sailplane and those of his friends. The pilot figures he has developed are literally works of art, incorporating design and engineering which allow articulated limbs and adjustable shoulder widths and including a white baseball cap, sunglasses, clothing in a choice of three colors, four-point harness and parachute bag, radio headset, and wristwatch. Pilots may be posed with their flexible limbs, and customized to fit a variety of scales from 1:4.5 through 1:3.5 and Ren also offers an English driving hat, flight suit, leather jacket, helmet and goggles!

In the press, magazines dedicated to the hobby regularly feature articles on soaring and scale subjects including RC Sport Flyer published by Wil Byers in Richland WA (http://www.rc-sf.com) and Aufwind published by Philipp Gardemin in Germany (http://www.aufwind-magazin.de) and Traplet Publications in the UK through Quiet and Electric Flight International offers excellent coverage of scale soaring and a variety of excellent sailplane plans designed by Chris Williams. All of these gentlemen are avid soaring enthusiasts sharing a passion for soaring as does Dr. Gary Fogel who provided an excellent photo essay published in RC Sport Flyer of the recent Schweizer model fly-in. Attended by Ren DiLeo, Mark Foster, Walt Gorecki, Carl Gwartney, Ken Kaye, Paul Krieger, Mike Lance, Angelo Orona, Sal Paluso and Don Scharf, it was sponsored by the Torrey Pines Scale Soaring Society (TPSSS). Another sought after publication is Radio Control Soaring Digest, a digital online magazine produced by Bill and Bunny Kuhlman in Oregon at http://www.rcsoaringdigest.com or through the Yahoo user group of the same name. They are now in their 26th year providing reader-submitted features in a variety of topics with outstanding photography.

Clubs and associations like TPSSS, may offer builders and flyers access to improved flying sites with controlled airspace, insurance against liability, or simply directions to or listings of public areas from which to fly. Larger non profit organizations may even sponsor chapter organizations or clubs, contests and awards and the opportunity for camaraderie among members. Here in the United States, the non-profit Academy of Model Aeronautics (AMA) has been providing such services promoting the hobby and encouraging its members in its monthly publication Model Aviation for nearly 75 years. The organization is a leader in supporting legislation that protects and develops the hobby through lobbying and offers a rich history of modeling excellence on display at their headquarters in Muncie, Indiana. (http://www.modelaircraft.org). The Model Aviation Association of Canada provides the same funtions and services to modelers across our northern border at http://www.maac.ca.

Regional and national clubs or associations operate and maintain excellent websites which include scale plans for download, calendars of flying events held annually or seasonally within their region, and how-to articles or group builds with instruction and assistance from master modelers. Most provide links to local clubs and flying sites in each country, province or geographic area. By doing so, they provide an excellent resource for both their regular members and those who wish to take up the hobby. Among those are http://www.soaringissa.org, www.scalesoaring.co.uk, and http://www.scalesoaringaustralia.com, http://www. More of these associations may easily be found by searching keywords “rc scale soaring” at GoogleTM.

My own family story is of being a son of an aeronautical engineer and NASA Flight Research Center (FRC) employee James A. Martin who happened to work along with Paul Bikle at Edwards AFB. My oldest brother is married to the daughter of Jim Moeller-Moeller crewed with Bikle on his altitude record attempts and towed him on the day in 1961 when two world records were set in the Schweizer 1-23E at 46,267 feet in the Sierra Lee Wave not very far from Edwards. I was only six years old at the time and have no recollection of this, but know that Bikle was a pioneer in aviation research with a passion for soaring and often published here. This same aircraft, the only E model manufactured, was constructed for Paul MacCready to compete in the 1954 World Gliding Championships in Madrid, where he flew to a fourth place finish.

Despite technological advances, I tend more to low tech wooden and welded steel sailplanes and employ the KISS method (keep it simple stupid) and enjoy these vintage subjects with no gadgetry. I like the nostalgia of early and simple aircraft designs, the pleasure of working from my own drawings to exact scale, and the challenge of searching and specking out in lift. I quess I am a 1-26 with three instruments in a world of ASW 27s with fully instrumented cockpits.

My first sailplane was a scale model of the ASW-15 which served me well in the high desert thermals and slopes surrounding the Antelope Valley in northern LA County California. I moved on to building all wood sailplanes, designing and constructing lost foam fiberglass models with sheeted foam wings and ulitmately moved away from the hobby in later years. After having been away for too long, I wanted to get back to scale soaring and had a desire to build a Schweizer 1-26E at about two to two-and-half meters but was unable to find any new kits available. I did find a 1-26B at three meters in a partial kit format (no hardware or sheet, spar or longeron and stringer stock provided) but when I consulted with the owner of the company about this kit,  I was told that I probably lacked the skills to build it. Not to be discouraged, I decided to purchase an old Sterling kit from an eBayTM seller and set about to build it.

Before I had even finished the 1-26 kit, I found one of the other revolutionary changes in the modeling world.... or the world for that matter -- social networking -- the internet. I soon discovered there were likely thousands of vintage sailplane enthusiasts in the modeling world, many of whom would welcome the opportunity to build U.S. vintage sailplanes from laser kits and many of whom soon became customers. Not only that, networking with outher enthusiasts on websites such as http://www.rcgroups.com and http://www.rcuniverse.com and http://www.wattflyer.com has enabled thousands of us to research products including kits and electronics, get first hand information about them and watch others build them in their workshops or do likewise and share our accomplishments with web surfers all around the globe.

And so, another business was born. And over the last five years, I've learned too that the demographic of sailplane enthusiasts is largely upper middle class men; many former military pilots; many own their own business or are business professionals; and all of them are fascinated with the history of soaring in the U.S. and with sailplanes. Its seems that a fair percentage have flown sailplanes and many have shared stories of their first flights and solos in Schwiezer SGS 2-22s. 2-33s and SGS 1-26s. Stories I welcome and love to listen to.

For little other reason than my own fascination with sailplanes and the Schwiezer Aircraft Corporation, I had decided to document and draft highly scale replicas of many their product line, beginning with the SGP 1-1 and finishing with the 1-36. With its venerable history as the oldest family-operated aircraft company in the world up until its sale to Sikorsky two years ago, it seemed almost unbelievable that no one was manufacturing and modeling these historic aircraft. Now many people are -- and just now, five years later I am finally completing my Sterling 1-26D from the original 70s kit. Maybe I’ll find time to fly it soon and one day see if one of our models can set a new altitude record for unpowered unmanned aircraft.

Our Custom Cut Spar Stock

I've just finished cutting wood spar stock for use in our quarter scale Piper PA-25 150 Pawnee kits. Due to the fact that it's readily available from our local Kansas City Missouri lumber yard, I've chosen to use C grade Douglas fir for the spar stock for all of our larger kits specifying dimensional wood structural members larger than those available from model aircraft supply houses such as Balsa USA, Sig, Midwest etc.

Before attempting any of these operations yourself, be sure to thoroughly read, understand and comply with the operation, safety and maintenance manual of your power tools as they are inherently dangerous and can cause serious injury and even death. Make sure your work area is safe and free from obstructions and trip hazards and that you are wearing all of the recommended safety equipment and that clothing cannot accidentally come in contact with the blade. In addition be sure to keep fingers and arms and hands well clear of the blade.

I generally choose a 1x6x12 and hand-select the piece by first checking for warps, twists, and cupping or crowning since I will have to straight-line one edge and rip the final parts on the table saw. Next I inspect both 5-1/4" faces for defects such as knots or pitch pockets and then examine the 1-1/2" edges by looking down the full length of the plank I looking for straight and tight growth ring spacing, 1/8" or less, and zero runoff of grain from one end of the board to the other. Usually the best boards will meet this criteria and I can usually find one or two boards that will work from the stack.But even if one or two growth rings run off in eight to twelve feet or knots are near one edge, a plank can be acceptable and I can work around these defects. A1x6x12 foot C grade fir board costs about $30.00 at my supplier.

Next I will place my board in the shop on a flat surface (better not to put it on the floor) and let it acclimate further to my shop and to make sure that it doesn't twist or warp over the next few weeks before I am ready to cut parts. This way if there are any stresses in the board due to moisture being trapped in the board from transport or storage before I purchase it, I will show up before I rip the board and get parts that are less than straight or suitable for kitting.

The first step in preparing the board for ripping parts on the table saw is to cross-cut the board to the nominal lengths needed and then straight-line one edge of each to remove the chamfered or rounded edges typical of dimensional construction lumber. I do this using an a thin-kerf carbide-tipped blade and an outfeed table to safely support the end of the heavy plank as it exits the table saw and blade and run the straightest edge against the rip fence set to remove only about 1/8" of material. I keep my blade clean and lubricated with dry-silicone spray to make the cleanest cuts without chatter or burning of the wood.

Next I set up my thin-strip ripping jig which I found in Wood Magazine in a construction article http://www.woodmagazine.com/wood/pdf/delta/da-00139rip.pdf. This handy jig may be made in a few hours using bits of plywood and hardwood scrap from the shop and a 1/4-20 x 1-1/2" flat head machine screw, washer and nut. It allows one to rip thin strips or parts on the left of the blade without the inherent danger of the workpiece being trapped between the blade and fence and being shot back at the operator by the rotation of the saw blade.

Once set up for the size of stock thickness needed, I rip cut as many pieces as needed to make up the number of parts called out by the kit or kits I am supplying. Finally, once all of the first cuts are made, I send the parts back through with the blade lowered for safety to just over the thickness of the pieces to rip each to its final width. This time since I am not cutting the full 1-1/2" thickness of the board I cut them in the usual way by setting up the rip fence to blade distance and run each final part against the fence.

Here are a few links of interest for making your own structural parts for scale model sailplanes:

Wood Magazine Thin-Strip Ripping Jig

Sport Air Article on Selecting Wood for Homebuilt Aircraft

Flight Magazine July 1943 Article on Wood for Aircraft Construction

Connections - The SGU 1-7

This is amazing. I just got off the phone with Howard Burr. He was the owner of the 1-7 that now hangs in the National Soaring Museum in Elmira and his dad, (same name) worked for Schweizer in the 40's through 1959 and helped design and build the 1-23, the 1-26 and owned and flew the 1-24.

Howard Junior who grew up in Elmira, told me he reached 32,000 feet over Skylark North Gliderport in Tehachapi where he now lives flying the 1-24 which was a constant-chord laminar-wing variation of the 1-23.

Howard purchased the SGU 1-7 for $250 in the early 60's and with two other high school aged friends, restored its damaged wing and made a canopy for it for flying in the cold Tehachapi air. His dad published a book on soaring and Howard is sending me a copy. They both new Paul Bickle who set the altitude record in the SGS 1-23E towing out of Skylark North.

When the book gets here I'll post more and Howard promised to send me his photo collection of the 1-7 to scan and post. Meantime, he will be building the "Little Flyer" SGU-1-7 real soon.

2-32 1:8 Scale Display Model

I've made some major progress on the eighth scale 2-32 display model. Its carved and shaped from solid pine (fuselage) and planks (wings and tails) using power tools and then drawknife, rasps, sanding blocks and finally the Dremel router to excavate the landing gear cavity.

 

Here is the process:

I've drawn plans for a eighth scale 2-32 for my BSS (Backpack Slope Scale) gliders which are a fully scale line of EPP foam sailplanes designed for beginning scale modelers flying slope or aerotow who need a more robust airframe, simpler and quicker build and the ability to fly and land in difficult landing zones on rocky or brushy western slopes.

After gluing up the lamination of 1x6 whitewood (pine) from the Home Depot for the fuselage, I took the plotted side and top views from the plans and cemented first the side template with Scotch 3M 77 adhesive to the block and band sawed out that shape and then affixed the top view template in the same manner and traced it out and band sawed out that profile.

Next using a 9" drawknife in the front vise of my workbench, I began to remove the square edges of the shaped block to define the curves of the fuselage, then further refined them using a farrier's rasp, cabinetmakers rasp and finally modelers sanding blocks with 100 grit paper. I marked out the limits of the panels that made up the cockpit/canopy opening and fairings and used carving knives to further define the break-line between the glazed and flat-wrapped sheet metal portions of the canopy, alternating with the cabinetmakers rasp until I was happy with the entire fuselage.

Next I sawed out the wings and tails from pine planks using the band saw for the empenage, and a special shop-made tapering jig I use for furniture parts on the table saw to cut the two wing planks. I purposely left the wings longer on both ends, the tails net, and using a combination of drawknife, rasps, belt sander and sanding blocks shaped the airfoil sections on each part, sealing and impregnating them with epoxy resin prior to final sanding and filling.

Then again using the templates from the plans, marked the end cuts on the wing panels and cut the 2.5 degree dihedral bevels and 35 degree tip bevels on my compound miter saw table. I traced the root of the wing on a scrap of 1/8" plywood and cut it out and sanded to my line to make a drilling alignment template. I transferred the shape from the template to the sides of the fuselage, carefully measuring to ensure both wings would be symmetrical to one-another and have the same incidence.

Using the drill press table I then drilled the 1/4" diameter main wing rod locations using a small ramp jig set to 2.5 degrees on the table under the fuselage to provide and ensure correct dihedral angles. (Drill press tilt is at the wrong axis and the main post would have interfered with such a long part). Then using the template I had made for the root profile, I pinned it in placed on each wing with the main rods, aligned it with my previous tracings and drilled the incidence 1/8" diameter wire holes through the drill guide/template using the same angle set ups on the jig used previouslyy, on each side of the fuselage.

Next I put each wing panels in the front vise and using a small framing square and a 6" combination square, aligned the roots parallel to the top of the vise jaw and then used the leveling bubble on my hand drill to repeat the drilling operation on the wings. This way I ensured that they would be parallel to the chord-line of the wings and dead-square to the roots. Using the sameguide/template held on the root by hand, I simply drilled the main holes first, inserted the pin to hold the template, and drilled the second smaller hole precisely spaced. I similarly drilled two indexing/mounting pins at 1/16" diameter into the root of the vertical fin and on the top of the fuselage and test fit all of the flying surfaces.

Next I measured and remarked the canopy opening panel lines with the fuselage held square on the bench using the small combination square and ruler. I then painted a coat of West System laminating epoxy and light filler mix on the entire fuselage and allowed it to fully cure, followed by about four hours of hand sanding with the sanding blocks and electric orbital sander to perfect the shape.

Then, using a narrow kerf dovetail saw sawed out the bulkhead former-to-canopy release cuts with the saw. Next I placed the fuselage back on the drill press and cut a series of 1/8" diameter holes along the hinge-line and latch-line of the canopy/cockpit block, halfway through from each side and then placing it on the floor mat, released the canopy tooling block with a 3/4" cabinetmakers chisel and my large mallet, working slowly from each side, deepening the plunges of the chisel so as not to damage the parts.

I then belt sanded out the drill marks and waste from the bottom of the canopy tool and marked, cut and epoxied a piece of 1/8" birch plywood to the bottom to make up the depth lost with the drill. I similarly flattened the waste off of the cockpit opening with the large rasp, finishing with sanding blocks and then filling with West System epoxy and filler and perfecting the edges and removing any tooling and shaping defects with block sanding.

After marking out the location of the main landing gear using measurements from the plan, I excavated the semi-hemispherical gear cavity (all compound curved) with a 3/8" diameter globe-shaped carbide cutter in the Dremel tool, cut, sanded and drilled two landing gear mount lugs from 1/8" carbon plate and test fit the 1" length axle and wheel and with the axle in place as a jig, cemented in the two lugs with epoxy and filler, gusseting them in with fillets of the same slurry.

Finally I assembled all of the parts and did the photo shoot. The model has to have removable parts for shipping and assembly on site as well as the future prospect of moving it safely. All of the parts can be adhered with small quantities of white acrylic adhesive caulk which can be carefully removed in the event of disassembly at some point in the future.

Next step was to send out the canopy tooling to my supplier for the clear parts and then paint the entire model with oil based white trim enamel, mask and paint the trim and apply decals including instrument panel, followed by packing and shipping to the customer.

 

Pretty sweet huh? Can I keep it? Mike says I need to post pictures of it being held by son or daughter so I suppose I'll oblige before it ships.

Tiny Gliders Postal Contest Underway...

If you bought our Stinger 8" catapult kit you may want to enter your times in the "Tiny Gliders Postal Contest". Here is the web site with complete details for the contest. Rules for the contest are:

Models are divided in four categories being:

6" HLG - Models with less than 6" wingspan, hand launched from the ground, jumping is allowed.

 6" CLG - Models with less than 6" wingspan, catapult launched by a conventional catapult (stick and rubber).

8" HLG - Models with less than 8" wingspan, hand launched from the ground, jumping is allowed. 

8" CLG - Models with less than 8" wingspan, catapult launched by a conventional catapult (stick and rubber). 

Flying:

All categories must fly 5 previously declared offical flights on sequence, adjusting and triming is permited between flights only if it is not declared as an official attemp. The best and worst times will be discarded and the remaining summed so the winner can be determined. Multiple entries are allowed.

 Launches must be made on near flat ground, no sloping flights are allowed.

 Any flight with 10s or less is not considered official, including previously declared official flights.

Maximum flight times for HLG is 60s and 90s for CLGs.  

 

From Jason Wentworth: Suggestions For F/F Kits...

One type of kit that is very rare nowadays is the peanut scale F/F (Free Flight) sailplane model.  Going by the 13" wing span -or- 9" length rule, peanut scale sailplane models would have ~15" - ~30" wing spans in most cases.  Such models would be a practical size for modelers who live in apartments, and in many cases the models could use all-sheet balsa wings, horizontal stabilizers, and vertical stabilizers.  Their fuselages could be tissue-covered "bulkheads-and-stringers" built-up structures or (in the case of some sailplanes that have large, flat fuselage panels) built-up structures with 1/64" sheet balsa skins.

If you produced peanut scale kits of several classic conventional sailplanes (such as the Antonov A-15 www.sailplanedirectory.com/PlaneDetails.cfm?planeID=460 , Niemi Sisu 1A www.sailplanedirectory.com/PlaneDetails.cfm?planeID=324 , Schweizer SGS 1-26 http://en.wikipedia.org/wiki/Schweizer_1-26 , Schweizer SGS 2-32 http://en.wikipedia.org/wiki/Schweizer_2-32 , and the Slingsby Skylark www.sailplanedirectory.com/PlaneDetails.cfm?planeID=328 ) and tailless sailplanes (such as the Armstrong Whitworth A.W.52G www.aviastar.org/air/england/arm_aw-52g.php , Backstrom EPB-1 Plank www.nurflugel.com/Nurflugel/Fauvel/e_backstrom.htm , Fauvel AV-36 & AV-22 www.nurflugel.com/Nurflugel/Fauvel/e_machines.htm , Horten H III f http://www.sailplanedirectory.com/PlaneDetails.cfm?planeID=144 , and the Marske Pioneer II http://www.nurflugel.com/Nurflugel/Fauvel/e_marske.htm ), I think they would be quite popular.

 

You could even offer Rapier www.rapier.cz powered models of turbojet-powered motorgliders such as the Fouga CM.8 Cyclone (also called the "Sylphe," see: http://aircraftwalkaround.hobbyvista.com/sylphe/sylphe.htm ) and the unusual twin-fuselage Fouga CM.88 Gemeaux (see: http://aircraftwalkaround.hobbyvista.com/sylphe/sylphe.htm ).  Peanut scale models of these jet motorgliders could use the cheaper and easier-to-acquire Rapier L-1 motors (the Rapier L-2, L-2HT, and L-3 motors sell out quickly).  [Shorty's Basement www.shortysbasement.com distributes Rapier motors and accessories in the USA.]

From Jason Wentworth: The Thermal Scout

Here are plans (see the attached PDF file) for a high-performance yet simple-to-build Hand-Launched Glider (HLG) called the "Thermal Scout," which would make a great laser-cut glider kit for beginners.  Its wings have simple dihedral rather then polyhedral, which makes them easier to build.  Also, it has short moment arms, which give it bouncy and forgiving flight characteristics.

 

The "Thermal Scout" has never been kitted, having been designed by a British Boy Scout group leader (hence its name) for his scout group to build.  Here is a link to the online illustrated construction article (see: www.f4bscale.worldonline.co.uk/scouts.htm ).

 

I have also reproduced the text of the building and flying instructions below, in order to provide fractional inch conversions for the metric balsa wood thicknesses that are given in the article.  Two other points: [1] The instructions call for using cyanoacrylate glue and epoxy glue at various steps, but aliphatic resin glue (yellow carpenter's wood glue) will also work fine for all of the glue joints;  [2] The instructions call for sanding the flat, rectangular cross-section fuselage to an oval cross-section, but this would weaken the fuselage--it's better to leave it "as is" or to just slightly round off the fuselage's square corners (as viewed from the front or rear).  Here are the instructions:

 

THERMAL SCOUT

 

 

Fuselage: 3/16" (5 mm) thick hard balsa (C-grain balsa, also called quarter-grain balsa)

 

Fuselage stiffener strip: 3/32" X 3/16" OR 1/16" X 3/16" (2 mm X 5 mm OR 1.5 mm X 5 mm) basswood or spruce strip

 

Wings: 3/16" (5 mm) thick medium/soft balsa (B-grain balsa)

 

Rudder: 1/16" (1.5 mm) thick medium/soft balsa (B-grain balsa)

 

Stab: 1/16" (1.5 mm) thick medium/soft balsa (B-grain balsa)

 

Grip: 3/16" (5 mm) thick medium/soft balsa (B-grain balsa)

 

BUILDING

Start by cutting out a ‘kit’ of parts.

Cut out the wing in one piece - plane and sand it to shape before cutting at the centre and then rejoining with Epoxy (50 mm dihedral each wing tip).

Cut out the tailplane and fin, sand their edges to about 0.5 mm thickness, leave the centre 4 mm of the tailplane untouched (flat) as it will be glued to the underside of the fuselage.

Cut the fuselage from 5 mm balsa sheet (hard C-grain balsa), cut it accurately as there is incidence built into the wing seat.  If you measure the wing seat position (on the fuselage) you will find that the rear of the wing is 1 mm lower than the front.

[More experienced builders will perhaps like to build up the fuselage as follows: - From the bottom up - 1.5 mm X 5 mm basswood or spruce strip, 5 mm X 5 mm hard balsa strip, the upper part of the fuselage can be Medium/Soft grade balsa.  This method will result in a strong/stiff/ light fuselage.]

Before sanding the rear of the fuselage to an oval section, glue ('Cyano’) the basswood or spruce strip to the bottom of the fuselage.  It is shown on the plan as 2 mm X 5 mm but 1.5 mm X 5 mm will suffice.  Round all the edges of the fuselage.

Join the wing to the fuselage with Epoxy glue.

Before fitting the tailplane sand the bottom of the fuselage rear end to accommodate the tail tilt (3 mm).  Use 'Cyano’ glue to attach the fin and tailplane.  Ensure that the fin is vertical.

Cut the finger grip from 5 mm balsa - bevel and taper to fit the underside of the right hand wing - ensure a good fit between the wing and fuselage as this will impart added strength to the wing / fuselage joint.

Finish the model with 2 to 3 coats of non-shrinking dope, sand with fine ‘wet and dry’ paper between coats.

FLYING

Build your model exactly to the plan, the scales should show an all-up weight of around 16 grams.  A visit to the local field (with long grass) will be required for testing, calm evenings are the best times for first flights.

Using Plasticine clay stuck to the nose, an initial balance point at around 50% of the wing chord should be established.  Check also that neither wing is heavier than the other - add a little plasticine clay tip weight to balance if necessary.  Test glide using shallow gentle hand launches, add or remove Plasticine clay until a flat shallow glide is achieved.

Once a flat glide is established - ensure that the model is also turning to the left.  If it is not then gently bend the rear of the fin to encourage a left turn.  When all is correct Thermal Scout should be launched up at an angle of about 40 degrees and to the right of the wind (with the wind in your face).  Launch by trotting forward a few steps and use a whipping arm action to launch.

From Jason Wentworth: A Horten IIIB Flying Wing

Chris Strachan in the UK just sent me a set of peanut scale model plans (see the two attached PDF files) of the German Horten IIIb Flying Wing sailplane and its powered Horten IIId motorglider variant.  He got it from his friend Bill Brown, a fellow model builder & flyer, and the plans were drawn by Bob Marchese here in the USA.  (Bob Marchese's plans service is long defunct.)

 

Chris Strachan has tried rubber power, a Gasparin G24 CO2 motor, and Rapier model jet propulsion motors in his Horten IIId model, all with varying levels of success.  His best results so far have been with a Brown A23 CO2 motor.  The Horten IIId plans show a HiLine Micro-4 electric motor installation.

 

The unpowered Horten IIIb model is also small enough to be launched as a parasite boost-glider (or as an Estes Nighthawk-style pop pod boost-glider with a bit of vertical fin area on the pod for yaw stability during powered flight).  The Horten has a much lower sink rate than the Nighthawk, though.

Earl Stahl Schweizer TG-2: Fuselage Pt. 2

After a great deal of sanding, shaping, and notching, I began to assemble the first half of the fuselage. The keels are held down with a pin bent in a Z shape. Formers were held vertical using pieces of angle iron with rare earth magnets to hold the jig together.
 

Former "B" was a bit of an issue. My solution was to use a piece of scrap wood to "block up" the non-attached end. I would be interested in hearing some feedback on a better way to do this on the other half. To me, this method seems hap-hazard.

 

One side complete.

 
Next comes the other half of the fuselage.  Remember, I am building the fuselage in two complete halves. That means two keels, each half as thick as the plan calls for.  The trick is that the second half has to be a mirror image.  One way to do this is to photocopy the plan and print a "mirror image".  My technique was far less complicated and lower tech.  I simply wiped the back side of the plan sheet with a paper towel dabbed in vegetable oil. 

 

The second half goes together the same as the first.  The two halves match up nicely.  A little bit of shaping will still be needed to blend the upper and lower keels with the formers.

New Cowl Products

I've just received the prototype parts for several new engine cowlings for the eighth scale 54" Taylorcraft, Aeronca Chief, Aeronca K and Schweizer SA 1-30. The parts look great and by making a couple of the larger and longer cowls two-piece parts with a joggle, production is more accurate and assembly simplified for the modeler.

With the new cowls we will produce an 1/8" (3mm) laser-cut lite ply firewall bulkhead and motor mount parts for simplified conversion to electric and gas power and eventually, plans revisions to show a simple and effective method for strut and landing gear mounting as well as a two-piece removable wing system for easy transport.

1-23 Maiden

Jim Gibson just successfully maidened his scale model of the SGS 1-23 with several tows to altitude and uneventful landings. Jim modeled his Schweizer kit after N91887 "Tinny Hawk", the D model flown by Paul MacCready at the 1953 Nationals to first place victory in Green and White color scheme. More images may be seen at http://www.rcgroups.com/forums/showpost.php?p=11743248&postcount=159 along with Jim's documentation of MacCready's historic airframe shown below with its current owners.

Jim's maiden was not without incident and his story shared here points to the need to not only document one's incidence and decalage but also the control throws and rates, the C of G location and trim conditions before first flight and every flight.

Jim asked for help in sorting out the condition that caused his initial ground loop (and minor damage) and I went to Herbert Eberbach for his take, not knowing the full details initially . I bring this up here to remind us all that its easy to get out of shape on tow when starting out and equally imperative to know the whole story to analyze the conditions that may have caused a mishap to understand and derive an appropriate solution.

Here is our correspondence:
Subject: 1-23 ground loop
5/28/09

Tom,

I aerotowed my 1-23 last weekend for its first flight and I had problems on takeoff. The 1-23 did not want to get airborne and I experienced a ground loop before about the same time my brain hit the release. Fortunately, damage was minor and I'm going to give it another go next weekend.

I think my decalage is off. I have the C.G. at roughly 76mm from the leading edge and I think approximately +1.5 degreees of decalage all based on Herbert's posts. Should the decalage be plus or minus relative to the wing?

Any input would be appreciated. I'll let you know how I do next weekend.

Jim

Subject: FW: 1-23 ground loop
5/28/09

Jim,

I've forwarded this message to Herbert as well so you can converse directly with him. He is the "resident" expert with the most flights on the 1/5 scale 1-23 so I would contact him for assistance.

In the meantime, your decalage measured as a positive angle is the difference between the positive incidence of the wing and the relative negative incidence of the horizontal stab. As shown on the plans the decalage is measured at 3 degrees and the balance point at 74mm.

What exactly did you experience after the plane came up to speed?

Tom

Subject: RE: FW: 1-23 ground loop
5/30/09

Hi Jim,

“I am glad to give you my two cents of advice,

First of all, I am not sure what you mean by "plus" degrees of decalage?! In any case, the elevator has to be in an "up-elevator" position with reference to the wing! C.G. at 74 mm with 3° decalage or C.G. at 76 mm with 1.5° are in "the same ballpark" and will not make much difference for the first flights.

Second, you experienced a ground loop while in the take-off run. This might be due to the fact that the 1-23 did not want to get off the ground due to the decalage, but there might be another reason - or maybe both work together in the wrong direction. Where did you position the tow hook? Apparently you have followed my build log and there I presented "my" hook position at the bottom of the front former. I do this always on purpose following bad experience some 30+ years ago.

This position yields a "natural line" from the sailplane`s C.G. slanted down to the hook of the tug. Second, and this is important if the hook is positioned higher, it may occur (particularly on a "rough" grass runway) that the pull from the tug is pulling the sailplane`s nose down somewhat. The plane is then "balancing" solely on its wheel without enough speed for the controls to be effective. The result is likely that it "falls" over to the side and/or nose which ends in a ground loop or even in flipping over on its back. (This exactly what happened to me when I arrived in a new club (after moving) with a new airplane as the experienced "aero-tower".

Hope it helps and happy landings, Jim. The 1-23 is a very nice and stable flyer. Feel free to ask more questions.

Herbert

Subject: RE: 1-23 ground loop
5/31/09

Herbert,

Our club had another aerotow this past weekend which gave me a chance to give the 1-23 another go.  This time---success!!  We had a beautiful day and I was able to get in about a half dozen tows.

Your comments were pretty much right on the money with the cause for my ground loop.  My 1-23 has 3 degrees of decalage(up elevator position relative to wing) with a CG pretty close to 76 mm from the leading edge.  I also discovered that when I had my ground loop I had maybe 2mm of down trim already in the elevator and my radio was not programmed for any aileron differential when in launch mode(rudder not coupled to ailerons).  Also, I did miss your original build post regarding tow hook position and my release is right at the end of the nose.  Sure enough, the 1-23 wants to hug the ground while the tug is still on the ground which I wasn’t expecting previously.  All of these items, when combined, caused the 1-23 to hug the ground on rollout.  I corrected my elevator trim and differential prior to this past weekend.  I apply just a touch of up elevator when it reaches flying speed and hold it until the tug is well clear of the ground.  Now I know why it’s a good idea to move the tow hook position down a bit.  Oh well, another lesson learned.

With the CG at 76mm I’m still carrying about 8mm(1/2 out on elevator) of up elevator for level flight.  A couple of dive tests confirmed the CG could still go back a little further.  How far back do you think I could go before I reach the center of lift(neutral position) for the wing?  Otherwise I’ll increase the decalage so I can get the elevator closer to a neutral position for level flight.

For your information, I’ve attached a couple of photos of my 1-23(D) with a little history of the full size that the color scheme is based on.

Jim

Great work guys in sorting it out and congratulations to Jim for his excellent build and successful maiden flight!

A reminder too, the TMRC 1-23 in 1:5 and new 1:4 scale come with parts and drawings to build all variants of the 1-23 from the "Standard" though the D, E, G, and H and H-15 variants. This provides a fleet of historic full scale ships and color schemes to model yours after! I suggest the shorter winged "Standard" and D models for slope flyers who will appreciate the faster roll rates but still want to fly a fifth or quarter scale ship at the aerotow field with the club.