Sorta Korda (oz12712)

About this Plan

Sorta Korda. Bostonian rubber model.

Quote: "Here's an entry for the West Coast Rules Bostonian Events .. .easy to build, and the author says it flies better than a Peanut Scale model! A charming little imitation Korda you'll love building.

The West Coast Rules Bostonian event is great! The models are easier to build than peanuts, and they fly better. The weight rule (14 grams) makes competition close, and one does not have to be an indoor specialist to be competitive.

Most of the published Bostonian designs I have seen are what I would call caricature scale. I fly old timer rubber models and it occurred to me to make a caricature old timer. The Korda/Lanzo style of old timer rubber ship is the most popular and easily recognizable of all old timers, so the choice was easy.

It turned out so cute that my friend Ron Robertti is scaling it up for R/C. Mine turned out to weigh 14.2 grams with a balsa propeller. It is stable, easy to trim, and with a free-wheeler should be able to compete outdoors in Embryo Endurance as well as Bostonian events - I made mine with a deeply undercambered airfoil, as an experiment. I think the undercambered wing, compared to a flat bottom-type, will give a better climb and glide for outdoor use, but for low ceiling indoor use I think a flat bottom airfoil is better. The under-cambered wing makes the ship climb well when enough power is applied, but it takes too much power for cruise. For indoor, what you want is a ship which can cruise with minimal power, and not much climb is needed; so the flat bottom airfoil is recommended. It would be possible to build both wings and use them on one model.

In our local indoor meets, at a 35-feet-to-the-rafters site, most Bostonian models do 45 to 60 seconds from ROG, but it takes 90 seconds to win. The difference between 60 and 90 seconds is an optimized relationship between trim, propeller, motor and plane, The best models seem to be underweight by 2 to 4 grams so that the ballast can be used to adjust the CG for trim without going over 14 grams.

The model presented here is drawn to fit the Mooney, or West Coast Bostonian rules, and is not a scaled Korda, it just 'sorta' is a Korda.

CONSTRUCTION NOTES The fin, stabilizer tips, and wine tips were made with two laminations of 1/16 x 1/32 bass wood which I cut with a Jones stripper from 1/32 bass sheet (Midwest) available at most hobby shops. I think balsa could be used, but I would suggest three layers. Lamination techniques have been well covered in this publication by Fernando Ramos and Walter Mooney. The wing spars are best added after the dihedral has been added to the wing..."

Direct submission to Outerzone.

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