Wasp III (oz5603)

About this Plan

Wasp III. Free flight rubber model by PG Chinn. From Aeromodeller September 1940.

Quote: "This month our contributor has a break from his usual article on 'Scale Design,' and describes the construction of a small type of high-wing cabin monoplane. In our next issue we shall publish another article by Mr Chinn in his series on Flying Model Designs.

THE original 'Wasp' was built about eighteen months ago; it was designed with a view toward obtaining maximum performance from a small model, and was therefore built on the lines of a large competition model. It is, in fact, more or less, a half-scale model of a typical light-weight contest machine.

The model presented here is an improvement on the original, and, although so far there has not been an opportunity of flying it under really good conditions, its performance should also be better. Non-thermal flying (which does not reflect the true capabilities of a model, anyway) showed the Wasp capable of clocking 90 to 100 seconds HL consistently on less than three-quarter turns, using six strands of 1/8 by 1-30 in rubber. On eight strands the model has a real rocket-like climb, and will shoot up in a tight spiral, but becomes rather sensitive to adjustment. The beginner would be wise in using four strands until he has become used to delicate trimming. Regular durations of more than a minute are easily obtained on this amount of rubber.

The Wasp incorporates the lifting-tail principal, now adopted almost universally by designers of competition models, but seldom used on small jobs. No difficulty in adjusting was experienced through this arrangement. Construction is, of course, almost entirely of balsa, and is quite straightforward. However, it is as well to remember that in building a model of this size the margin of error must be very small. A slight mistake, which would have little effect on a big machine, will be magnified many times in a model such as this.

Now, will all those who, having read so far and studied the plans, think this model worthy of their labours, please step forward - dear me, only one, a beginner, too - oh well, here goes:

Fuselage and Undercart: First cover the drawing with waxed paper (to prevent the wood from sticking to it, Johnny, and you can get waxed paper from your corn-flakes packet). Now bind the top pair of longerons together with fine thread and gently bend them to shape whilst holding in a jet of steam. Do the same with the bottom pair, and then when quite dry (making sure that they are still in shape) take off the binding, and attach one top and one bottom longeron to the plan - pin each side of the strips, of course, not through the wood. By the way, do not think that because the longeron will bend to shape dry without cracking it is not necessary to steam them - it is ! You will find your fuselage sides warped when removed from the board, unless the longerons are shaped first. Don't try soaking the wood and pinning it to the plan either - that, too, won't work!

Next, cement in the side members. Upright 'J' is of 1/16 medium balsa, and should be pierced to take the 1/8 by 1/32 bamboo rubber-peg. Build the second side on top of the first to ensure accuracy, then remove them from the plans and join with spacers at stations E, F and G.

Making sure that everything is square, the rest of the spacers may be cemented in. Members at 'K' should be accurately cut to leave an opening 3/16 in wide at the rear end of the fuselage. Note that there is an extra spacer at 'B' to serve as a reinforcement for the undercart tubes..."

Direct submission to Outerzone.

Supplementary file notes

Planfile includes article.

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