Plan file details
Nipper Mk 2. Control line speed model for 2.5cc engine.
Quote: "GADGET GIBBS tells you how to build and fly the NIPPER, 2.5 cc World record holder.
Ray 'Gadget' Gibbs is without doubt one of the most consistent and successful speed fliers in this country and in addition to his many contest placings he at present holds two of the three FAI world speed records. In this article he gives constructional details for his 2.5 cc Nipper model, and passes on some of his incomparable 'know how' on the preparation and flying of speed models in general.
THE Nipper, so called because it is built to the smallest of the three FAI classes, is an easy model to build and fly, but, as with every other form of competitive flying, practice is necessary for success.
Construction. The bottom half is made of hard wood, so that the screws holding the engine mount, which is made of 1/8 in dural, can hold firmly. The top is made of balsa and is constructed from two pieces of block to enable the wing to be inserted and securely cemented. The wing is sanded to section before the grooves are cut for the lead-outs. The tailplane is screwed to the bottom half. This, I think, is stronger and enables it to be replaced easily.
Props. The best props I have found are the American Tornado series; these are very well designed and made, and definitely give increased thrust in the air over any other prop. The right pitch can only be found by trial and error; much depends on how well the model is finished. I do not produce a fantastic finish and have found a 6 x 9 in prop the best, but a very clean model might possibly get away with a 6 x 10 in, and of course this should give more speed, but there is no point in using a high pitched prop if the model will not allow the motor to reach its peak rpm. With the engine working below its peak it is useless, for one cannot hope to get the speed if one does not let the motor rev.
Fuel and Engines. The original model was powered with a glowplug engine, because glow fuel gives greater scope than diesel fuel for experimenting with " hot " mixtures. Also one can use a fountain pen bladder as a tank (diesel fuel will quickly rot these rubber bladders). As a pen bladder feeds under pressure it will give a better engine run throughout the flight..."
Update 31/07/2018: added article, thanks to RFJ.
Update 01/08/2018: Replaced this plan with a clearer copy (patterned background removed), thanks to rchopper56.