Gadfly (oz2475)


Gadfly (oz2475) by Sherman Gillespie 1955 - plan thumbnail

About this Plan

Gadfly. Scale rubber model of the 1929 Glenny & Henderson Gadfly. MAN April 1955. Sherman Gillespie.

Quote: "Charming little rubber powered, semi-scale model of historic light plane rewards neat builders with wonderful flights. Gadfly, by Sherman Gillespie.

The Gadfly is a semi-scale model of the Glenny & Henderson plane that was flying in England in 1929. Powered by a 2 cyl, 40 hp engine, the little single-seater cruised at 72 mph. Top speed was 91 mph and it landed at 45 mph. Its ceiling was 13,000 ft. In its day it was quite an efficient machine.

The model is a very realistic flier with a phenomenal glide. It can do up to 30 seconds, hand-wound, in cool evening air. Warm air tests gave many flights of from 40 to 57 seconds. The ship shown was lost after a spectacular flight of 2 minutes 34 seconds! This, of course, was the result of a thermal but, when last seen high over a cherry orchard, the little job was soaring beautifully.

Construction is conventional but use care to keep the weight down. Complete flying weight should be approximately .8 oz.

Build the fuselage sides from medium hard 1/16 square balsa. Set the sides up over the top view and put in the 1/16 square cross-pieces. Cement the formers directly to these cross-pieces. Formers No's 1, 3 and 4 are cut from 1/16 sheet and are notched to receive the ends of the stringers. Formers No's 2, 5, 6, 7, 8 and 9 are cut from 1/32 sheet. The stringers are spaced and cemented on without notching these 1/32 formers.

Cut the nose block from fairly soft 1/2 in. stock and drill it to receive the 3/8 in. shaft of the thrust button. Although a hardwood button was used, a laminated balsa or plastic type may be fitted satisfactorily.

The dummy engine is not necessary for a strictly flying model. If it is left off, however, heavier wheels may be needed to balance the model properly..."

Update 09/09/2020: Replaced this plan, have re-aligned and adjusted the previous version which had the magazine centre-fold distorting the wing-rib spacing and shortening the fuse betweeen F6 and 7.

Supplementary file notes

Previous scan version.


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Gadfly (oz2475) by Sherman Gillespie 1955 - model pic


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Gadfly (oz2475) by Sherman Gillespie 1955 - pic 003.jpg
Gadfly (oz2475) by Sherman Gillespie 1955 - pic 004.jpg

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User comments

I have built four models over the years from this plan of the Glenny & Henderson 'Gadfly' by Sherman Gillespie. This is without a doubt the best flying rubber-powered scale model I have ever built in 50+ years of model building. Smooth ROGs, stable realistic flight, and beautiful landings. Anything designed by Sherman Gillespie flies well! The 'Gadfly' was an entry in the famous Lympne Trials, a competition for ultralight aircraft in the 1920s.
Planeman - 22/02/2014
Just checking, what's the correct wingspan on this model, as published? Should be 18 inches I think, but this file here is closer to 20 now.
SteveWMD - 09/09/2020
Got it, if wing on the printed page measures CL to tip at 24.6 cm (thanks Pit) then this plan here is correct to within 2 mm. Will list this one now as 19 in span, which is to the nearest inch, rounded down. Thanks,
SteveWMD - 09/09/2020
All Gillespie's model are wonderful flyer, but his history is very interesting too, see:
pit - 09/09/2020
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