Apprentice (oz1621)

About this Plan

Apprentice. Radio control power-assisted glider. For .020 power and single channel radio. Presented with Aeromodeller Aug 1968.

Quote: "AN APPRENTICE, according to the dictionary, is a leaner of a craft. The model presented on this months free plan is designed to help the modeller achieve just this, to learn the craft of single channel radio control flying. There is no doubt that flying single channel models is a craft and it is something that has to be learnt through patience, and a lot of practice! The Apprentice will help you to become a fully proficient single channel pilot by virtue of its robust structure and easy to operate features.

The design was developed from the Picconnini, a 36 in span all-sheet model fitted with a Cox. 010 engine and Webra Picco magnetic actuator and R/C equipment. Because of the very pleasant flying characteristics of this model it was decided to make a larger version with the necessary structural modifications so that it would be suitable for a wider range of R/C equipment. Although the engine is desirable for flying from most fields, the Apprentice can also be flown as a pure glider. So if you have a slope soaring site handy, or you are it enough to tow up models on the line, why not make a spare pair of wings for some silent flight. The hook can easily be added under the fuselage.

A word of warning here about the size of engines. For the beginner a Cox .020 Pee Wee or Cox TD.020 will give adequate power for learning to fly. With the Cox .049 Babe Bee engine installed, the model is quite fast, this is fine provided you have enough experience in flying and your reactions are good. Make sure the propeller is always well balanced and the engine is running with as little vibration as possible. With the engine mounted on a pylon, as it is in this design, any undue vibration tends to build up dive to the flexibility of the pylon. See photographs for general simplicity of structure.

Construction Although the construction shown is most suitable for the modeller who has only a limited amount of experience in building and flying the more advanced may wish to experiment with other ideas. For example:

(1) If each wing is reduced by two bays and the whole of the wing sheeted with 1/16 in balsa, a fast aerobatic model will result.
(2) The tailplane may be cut from 1/8 in medium sheet balsa instead of the built up unit as shown. (Some change of incidence may be found to be necessary).
(3) A single surface 3/32 in sheet balsa wing with strip leading and trailing edges but no spar can be employed if desired. This wing may be tapered towards the tip and washout built in to prevent tip stalling.

The construction as shown on the drawings should not present any difficulties, standard materials and building methods are used... "

Update 10/12/2013: Replaced this plan with a clearer version, thanks to JJ.

Update 12/03/2018: Added article, thanks to RFJ.

Update 10/08/2021: Added pdf build log, thanks to Nick Ward.

Supplementary file notes

Article.
Build log.

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