We urge you to read the top section of this page before buying a kit or starting your project!  Rarely does a beginner get lucky when flying in competitions. Like any other sport, training for experience will prepare you to win. Plan ahead. The process of winning requires careful building, test flights, adjustments and modifications. 
1. Selecting a model and supplies  
2. Specific Product Modifications
3. New information on selecting a motor.
SCHOOLS: PO's accepted, but ALL TRANSACTIONS ARE PREPAID.
(Please read Details below.) 

1. Selection of a model:
     The models on these pages (links at right) are recommended for competition. They are modifiable, and come with clear, easy-to-follow directions and diagrams, including suggestions for competitive modification and fine-tuning.
       The Harlan Cruiser 78 and Floater 78 are the only commercially available models that are designed each year specifically for the SO Division C and B rules to maximize performance for the current specifications. Includes individually hand-weighed balsa pieces to maximize strength-weight ration for each part of the model, and a supply of Mylar, much better than tissue. Cruiser has specially designed Ikara Props. As always there will be a limited supply.
       Both models are available to order now, for shipment in late October  - early November.  

      The Sorcerer is unchanged from 2005, but modification for 2008 Division C  rules should be quite easy.  The Sorcer has been used for a number of years to produce winning competition models, and is still (for the moment, anyway) only $32.95. The Sorcerer is in stock and ready to ship.

     If you have never built a stick & tissue model before, or have not allowed enough time for adjustment and testing, consider starting with the Shoebox or Right Flyer, both of which are modifiable and are competitive at the local and state level. You will gain experience which can be applied to your next event, for which we recommend a Cruiser or Sorcerer. Make sure to plan further ahead next time.
     All our competition kits, including the Delta Dart, Super Delta Dart, Shoebox R.O.G., and Right Flyer, are excellent candidates for developing your own winning  combinations. The Delta Dart and Super Dart, however, are not really recommended for Science Olympiad  or similar competitions.  They are ideal for beginners who are learning how to assemble, adjust, and fly balsa and tissue kits, and who are just starting to lean about aerodynamics.  The Delta Dart and Super Dart are especially easy to work with for younger (8 years +) students, since the components are glued directly to the plans, and it is possible to assemble with a glue stick in addition to a liquid glue. Both can be flown outdoors just for fun on calm (no wind), dry days.      The Shoebox ROG is a good first competitive choice for students with some building and flying experience.  It qualifies for competition, and is a very competitive endurance flyer in its size class if built carefully and adjusted properly. The Right Flyer is a fully competitive choice for longer indoor endurance flights, although a bit heavy for its size. It can be flown outdoors on calm, dry days, and is rugged enough to survive the occasional minor mishap.

     Our Build-N-Fly and Ready-to-Fly models (specifically the G-75 Flying machine) are also strong fliers, and may be used by beginners to acquire experience in building and flying rubber-powered balsa models. Endurance flying modifications are not included in the directions, but a knowledge of simple aerodynamics allows some productive tinkering. They are not considered contest-winning designs (too heavy, among other things). 

Do the job right with the right  supplies and accessories
Working with these supplies and tools requires practise, learning, and some ingenuity and improvising.
1. Work Surface:  We suggest using an accurately flat, sufficiently large, soft balsa or pine board or piece of 3/4" softwood plywood, clean, flat heavyweight corrugated boxboard, 2’ x 2’ ceiling tile, or dense insulation foam board as a construction surface for use with these pins. Cover work surface with wax paper to permit easy removal of finished assemblies.
2.  Assembly Pins:   These make the job easier, produce better quality work. Two structure sides can be duplicated, one one top of the other with wax paper in between, for symmetric structure precision. Also provides light clamping pressure for setting glue joints at any angle. Use the pin shoulders to hold the work, or pin through a piece of scrap used to press the work to the workboard.  Gentle side pressure can be applied to keep joints in place while drying, and cambered ribs can be held vertical with 1 or 2 pins on each side of the rib. Note: Use very light pressure on balsa parts and do not pin through balsa on Cruiser or Sorcerer models! Weighting the parts with 1/2" washers is the preferred method of Ray Harlan, designer of the Cruiser. We still think assembly pins are better if correctly used. 
3.  Speed Winders are a necessity for competition, especially for the Cruiser & Sorcerer, which may require more than 1500 winds. Also aids in precise counting of winds, which is an essential part of testing and adjustment for optimum flight. Use M388 15:1 winder for Cruiser & Sorcerer; M389 5:1 is OK for other models. ALWAYS COUNT THE NUMBER OF WINDS! 
4.  Mylar Film
We now offer 1.4µ Mylar film in rolls 12.5” x 10’, enough for covering several models.  It is superior to tissue in several ways.  It is included with the Cruiser kits, and may be purchased separately for $11.50 for the Sorcerers. We include updated instructions for use.  Application takes some practice, but it is worth the effort.
5.  Excel Brand single edge razor blades. Single edge blades are the choice of experienced modeler. Our blades are sharper than Xacto blades, more effective for most cuts, and make beautifully clean cuts if used skilfully.  However, they are also more hazardous to handle, must be disposed of safely, and are not recommended for children younger than 12 years.  We offer them in 10-packs for $2.50 with your order of other supplies - no additional freight charge.  We will not ship them separately! 
6. Our Ikara Propellers are designed by Ray Harlan. They feature a highly efficient combination of weight, size, shape, and pitch, and are not available elsewhere.  They are extremely light and easy to modify. They twist easily to change pitch angle, and can be reshaped with sharp scissors to change diameter and surface area. Although designed for the Cruiser, they are available separately (see URL above) to enhance the performance of the Sorcerer or other model. Only $7.50 for 2.  

7.  Care and selection of Rubber Motors:
Flight Central offers a variety of thicknesses of competition rubber string. For longest life and maximum performance, lubricate the rubber motors with Armorall, Formula 2001, or Son-Of-A-Gun (automotive supply or hardware store). Store motors in marked Zip-Lock Bags. Use Speedwinders for proper stretch-winding (directions in model kit package), and always count winds. Select motor acording to weight specs and energy requirements, model weight and room dimensions, among other things. See individual product page or accessory page for motor recommendations (online at Flight Central).
New:
 The selection of a motor, and determination of length, is dependent in part on the ceiling height of the competition venue and the prop pitch angle.  You need enough torque to get the plane up to the ceiling in a steady, gradual climb. The torque curve at that height should yield just enough to start the plane flying level, after which it descends under power.  Also, the greater the prop pitch angle, the more torque you need.  High ceiling, steep prop pitch indicates more rubber mass.  A thinner rubber gets more winds and a shallow prop pitch, spins faster.  A thinner rubber may not provide the power needed for climbing.  Experiment!  There is no straightforward formula for calculating this.  Another variable is number of winds.  Yes, we sell replacement motors.
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8. Adhesives:
A. Ambroid Cement  is the choice of many experts. It is very forgiving, does not require joint pressure, and can be removed from an incorrectly built joint with acetone. Apply sparingly with toothpick or balsa sliver. Where weight is critical, do not follow tube directions; apply to one part only.  Where strength is more important, apply to both parts, rub into wood and remove excess, allow to dry a few minutes, then reapply to one part and mate surfaces. Hold in place until dry with gentle pressure with pins. (Ambroid is similar to Duco Cement, the old standby, at hardware or hobby stores.) Ambroid Cement is available online at Flight Central’s Competition Section (see URL above) for $2.95 for 1.8 oz tube. 
Potential Negatives: Contains VOC's (volatile organic compounds) which may create an inhalation hazard. Use with adequate ventilation. Also hardens by drying, rather than curing, so open tube may harden up before it has been completely used. Do not pour working supply into dish or cup. 
B. We also recommend a water-based glue such as Elmer's Professional Carpenters Glue or Titebond II, which can be cleaned up (before they set - approximately 20 minutes) with water, and afterwards, with some difficulty, with hot water.  A properly established joint using them is very strong, and has a very slight flexibility. They have only fair initial tack strength, unless heavy clamping pressure is used (not possible with these delicate materials). NOTE: Grip Pins allow some clamping pressure to be applied either vertically or laterally at almost any angle. These glues are minimally toxic and are almost completely free of VOC's. Pour a little into a disposable cup, apply sparingly with toothpick or stick of balsa.
Potential Negatives: They work best when contact between wood pieces is precise and intimate, and some pressure can be maintained until they set (use pins). They do not hold as well on end-grain as they do on side or face grain. They are only slightly thixotropic, i.e., a large drop of this kind of glue on a vertical surface will run a little. Assemblies must be allowed to set at least one hour before being moved.

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Delta Dart

Super Delta Dart 

Shoebox R.O.G.

Right Flyer

The Sorcerer

Harlan '08 Cruiser & Floater

Accessories & Supplies

Competition Airplanes Home Page

Competition Airplanes Home Page

Delta Dart

Super Delta Dart 

Shoebox R.O.G.

Right Flyer

The Sorcerer

Harlan '08 Cruiser & Floater

Accessories & Supplies

Competition Airplanes Home Page

Boomilever & Tower Supplies 

Specific Product Modifications   
Expect to change or modify kit models for higher performance.

RULE #1:
Weigh everything precisely! Make certain that your airplane is the lowest permitted weight and the motor the greatest weight allowed under your contest rules.

Delta Dart  
The suggested modifications include the following in an ascending order of difficulty:
a) Replace the stock motor with our #379, Shoebox R.O.G. Replacement Motors.Tie in overhand knot, apply a small dot of "super glue" behind the knot and lubricate with Armorall (automotive supply or hardware store) or Son-Of-A-Gun.  Store motors in marked Zip-Lock Bags .  Rubber motor should be as close to a 300mm loop as possible.

b)Stretch-wind rubber motor with a winder to achieve maximum number of winds. Use our #389 5 to 1 Motor Winder).

c) Add Trim Tabs- Glue stiff paper tabs onto the trailing edges for wing ailerons, the fin's rudder, and stabilizer's elevator.

d) Construct the wing with a reduced dihedral angle. Build and pin the center section down on your work board. Raise the wing tips up to 38mm (1.5") and glue the leading and trailing edge juncture points. When dry, attach to the fuselage top per the instructions. This lower dihedral is much more efficient for indoor flying.

e) Change the motor hook. Instead of using a straight pin for attaching the rubber motor, use this idea. Bend half the straight pin (starting from the head) into a "c" shape with long-nosed pliers. Bend the other half so that it may be pushed up into the bottom of the fuselage. Wrap the pin and fuselage together and coat with glue. This makes a more secure attachment when using the longer motors. Adding a wedge so that the new C-pin is suspended even lower will minimize friction between the rubber motor and fuselage (during unwinding) for even better efficiency.     Top Of Page

    
SHOEBOX R.O.G. 
Notes: Since Shoebox R.O.G. is offered as an 8-pack, there are sufficient "spare parts" for modifying one or two models for contest flying from the remaining airplane components. Also refer to the list under the Delta Dart Modifications for standard modifications.

a) Fly the model without the landing gear if the rules allow. This minimizes both excess mass and drag from the model.

b) Use a winder for maximum winds on the rubber motor (see "b" under Delta Dart Modifications).

c) Lower the wing loading: This is a ratio of the overall weight to wing area. The lower this ratio is, the more efficient the model becomes. Various modifications may be incorporated to accomplish a lower wing loading. Increase the wingspan and/or chord to create wings with more area. Be sure not to exceed the maximum wingspan (projected view) in your competition rules. An easy modification is to increase the span on the wing's center section and leave the wing tips in their stock format. Further variations include replacing the 1/16" strip ribs with cambered ribs cut from 1/16" sheet. The added airfoil allows the model to fly closer to a nose high, stall attitude without porpoising.  This higher angle of attack will slow the prop and the model down for even longer flights.

d) Extended fuselage: A good rule of thumb is that the fuselage should be at least 80% of the wingspan to achieve correct nose moment arm and tail moment arm dimensions. Adding a tail boom is the easiest and lightest way to increase the tail moment arm length. Use either a laminated boom made from two 1/16" x 1/8" balsa strips or a stiff piece of 1/8" balsa strip to lengthen the fuselage. Mount the boom on top of the fuselage beginning at the point where the leading edge of the fin would have been mounted. Attach the stabilizer, tissue up on top of the boom end with the fin on top. Leave the motor hook in the original location.

e) Manufacture a higher, lighter pylon assembly for the wing. Design it so that it may be shifted fore and aft for changing the center of gravity. Two upright 3/32" stiff balsa strips connected to a "saddle" will minimize the effects of the propeller turbulence on the wing's lift. Use the small rubber bands for attaching the assembly to the fuselage.

f) Shave and re-pitch the propeller for better performance. Refer to the Teaching Tips enclosed in the kit.          Top Of Page

     
RIGHT FLYER    
The Right Flyer can be quite a performer if its wing loading is also minimized. Review the Shoebox R.O.G. modifications for ideas, too.

a) Convert to #379, Shoebox R.O.G. (.093" crossection) rubber motors for longer contest flights (see Delta Dart modifications "a" and "b").

b) Remove the Landing Gear if rules allow.

c) Cover all the flying surfaces with craft tissue or even Japanese Tissue. Use a fresh glue stick for applying the tissue to these surfaces. Only cover the top surfaces.

d) Increase the wingspan for more area. Possibly convert to tip dihedral or even a polyhedral design.

e) Extend the fuselage much like the procedure for the Shoebox R.O.G. (see Shoebox modifications "d")

f) Modify the wing pylon/ saddle (see Shoebox modifications "e")

g) Shave the prop to reduce mass and make it flexible for re-pitching. Use a fresh X-acto #11 blade and shave the front, cambered surface until 1/3 of mass is removed. In doing so for both blades, the propeller may also be balanced.

After freewheeling a balanced prop, it should stop with the blades horizontal and not vertical. Re-pitch the prop for a longer motor run and less climb. Twist the blades so that the leading edges have a higher angle of attack. 
      
Sorcerer
See kit package directions for additional modifications.

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Delta Dart

Super Delta Dart 

Shoebox R.O.G.

Right Flyer

The Sorcerer

Harlan '08 Cruiser & Floater

Accessories & Supplies

Competition Airplanes Home Page

Boomilever & Tower Supplies 

Delta Dart

Super Delta Dart 

Shoebox R.O.G.

Right Flyer

The Sorcerer

Harlan '05 Cruiser

Accessories & Supplies

Competition Airplanes Home Page

Boomilever & Tower Supplies 

Delta Dart

Super Delta Dart 

Shoebox R.O.G.

Right Flyer

The Sorcerer

Harlan '08 Cruiser & Floater

New! Boomilever & Tower Supplies 

Accessories & Supplies 

or Fax: 
802-888-3155

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