Kadet (oz2950)

About this Plan

Sig Kadet. Radio control trainer for .19 - .40 engines. This is the plan from the original 1972 Kadet design, which is now out of production and unavailable. The 3rd plan sheet shows ailerons modification.

Quote: "The Kadet is a stable and easy-to-fly model, ideal for the novice pilot learning R/C. Since it will fly hands-off - free flight fashion - when trimmed out, a buddy box type of transmitter is not required to instruct beginners. It is even possible for a new flier to teach himself how to fly without the assistance of an expert. A fine sport model for Sunday fliers, the rugged balsa construction allows it to take the punishment of every day flying. The structure resists fatigue and vibration damage.

RADIO EQUIPMENT REQUIREMENTS: For best results, install 3 channel equipment in the Kadet. One or two channel equipment can be used with less flexibility in control. Also you can install 4 or more channel equipment and use only 3 of the channels. The fuselage is large enough to carry a standard battery pack and standard size servos.

Selection of radio equipment should be based on the amount of money you wish to spend, the type of airplanes you intend to be flying and your future goals. If you plan to stay in the hobby and work up to larger airplanes with complete controls, it might be best to consider purchase of a four, or more, channel set in the beginning. It could be used with three servos to fly the Kadet and later installed in an intermediate aileron trainer like the Sig Komander (oz9124) with the simple addition of another servo. This would eliminate the necessity of disposing of a initial investment in beginner's equipment of less than 4 channels and buying a new set when your flying skills are ready for an advanced model.

IMPORTANT: If the Kadet is flown with 4 channel radio equipment, plug the rudder servo into the receiver outlet marked 'aileron'. This will enable you to develop the proper left and right reactions that will later be needed when advancing to an aileron-controlled model. On an aileron model, the rudder is used only for ground steering and some specialized acrobatic maneuvers. Getting used to this extra function, using your other hand, is a much easier transition from three to four channel operation than would be the case if you had to change hands on the primary turn-ing function. (Which would be required if you had been flying the Kadet with the rudder servo plugged into the 'rudder' output socket of the receiver.) The important thing you are learning is an automatic left and right reaction on a particular transmitter stick with a particular hand. Forget which control surface is doing the turning on the Kadet, assume that the rudder is an aileron.

ENGINE SIZE: The original Kadet was flown with a muffled Fox .25. A .19 would be adequate on a light Kadet, or one with less than three channels. Remember that a muffler will reduce engine power and allowance should be made for this. Beginners should fly .29 to .35 powered Kadets with the motor throttled back to 1/2 or 3/4 power until they are familiar with the airplane and have some flying time.

ENGINE THRUST OFFSETS: One of the purposes of a flat-bottomed high wing trainer is to be self righting when control goofs are made. With a Kadet built as the plan indicates, if the flier gets disoriented or accidently puts the Kadet into a dangerous position, simp-ly let the control sticks return to neutral and the Kadet will either right itself or partially do so and give the pilot time to think and apply a correct control signal. It is safer, in situations like this, if the Kadet continues to gain altitude. Later, as piloting skill is acquired, you may add dowrithrust to the engine, if desired, or use the trim feature of the radio equip-ment to introduce a small amount of down elevator. Practice in the use of the trim levers is a necessary part of becoming an expert flier.

Right thrust offset is not required in t he Kadet.

ABOUT THE WING INCIDENCE: One of the safety factors for hands-off stability in the Kadet design is the incorporation of some incidence angle in the wing. After you learn to fly, or if, as many modelers do, the Kadet is used as a sport and fun flying model, you may want to reduce the amount of wing incidence so the mode! will not climb much under power and has less tendency to zoom upon fast recovery from a turn. A 3/32 in shim at the wing trailing edge will reduce the wing to zero incidence. Fill in the gap in the top of the cabin with a long, wedge-shaped piece of wood so that there will be no oil leakage into the cabin. DO NOT tamper with the incidence unless you are an ex-perienced flier. Beginners should build the Kadet as spee-ded by the plans.

WOOD SIZE SUBSTITUTIONS: Due to the balsa wood shortage, it is sometimes necessary to supply alternate sizes of 3/32 planking sheets. For example, 2 in or 2-1/2 in wide sheet may be substituted for part of the 3 in wide sheets usually supplied. Use the 3 in wide sheets for the leading edge of the wing. Use the narrow widths for the fuselage top and bottom planking, wing center section and wing trailing edge lower sheet. It is also necessary at times to supply 24 in lengths of 1/16 x 3 in sheet for the stabilizer instead of 36 in lengths. However, since the stabilizer planking instructions require that the 36 in lengths be cut into 24 in" and 12 in lengths, the substitution of 24 in lengths causes no change in actual construction.

BEFORE BEGINNING CONSTRUCTION: We have listed step-by-step assembly instructions, keyed by paragraph to the isometric drawings. It is suggested that you read the entire instruction book and study the plans carefully before beginning to build. You may wish to work on several parts at the same time and this is possible in many cases.

Wax paper may be used to protect the plan during building when the glue used is Sig Epoxy or an aliphatic resin such as Sig Bond. If a model cement like Sig-lent is selected, use plastic wrap to protect the drawing because this glue will dissolve the wax out of the wax paper and will not set up properly..."

Update 24/01/12: Ed mailed in to say: "The formers on the Kadet are complete. There was only the ply firewall, the main ply cabin former at the front of the wing, and two balsa formers for the rounded top section at the nose. everything else was built-up stick cross-members, from the trailing edge right back to the tail."

Update 05/05/2020: Added kit review from Model Builder February 1980, thanks to RFJ.

Update 28/9/2024: Replaced the manual with a clearer copy, thanks to Bobj.

Quote: "Steve, Mary, Hello! I’m sending you a revised version of the manual for this one. I’m using jpegs that I downloaded years ago. They are exactly the same scans that are used in the current version. The revised version no longer starts with page 10, and now includes the missing page 4. Also, I have made the aileron modification pages a separate document. It is numbered differently and doesn’t match the lettered sequence of the rest of the manual. It seems to make things a little clearer that way. Bobj"

Supplementary file notes

Manual.
Manual (aileron wing).
Review.

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