Stray Tupp. Folding-wing catapult-launch glider model.
Quote: "THE writer 'dreamed-up' the theory for this type of model several years ago, when chuck gliders were in their heyday. Not until recently, however, has the time been available to put it into practice. It has now been proved to operate successfully on the simple model shown here, and no doubt once the principle is grasped, modellers will be able to develop larger and even more efficient versions for themselves.
Now, normally, the height which a chuck glider can reach (apart from when they catch thermals) is rather limited, even when extra force is applied in the form of a catapult. If, however, as on our model, the wings can be folded back, so as to produce zero lift, the model can be 'shot' vertically to a considerable height. The wings then fold outwards into flying position and the model commences its flight.
Building the model. Usual solid glider methods are used - the important part being the wing attachment. The ply mount must be cemented through the fuselage at the exact position shown on plan. The wedge-shaped dihedral-keepers are cemented to the wings and reinforced as shown. 9 BA bolts are used for the swivel attachment, with washers on each side. The wings should swing freely, but not to be extent of being wobbly. The 1/8 in balsa stops fitted on each side of the fuselage will keep the incidence correct. NB The wings fold under the tailplane and parallel with it.
The catch (see plan) and pendulum are made up from 20 gauge wire, the catch being threaded through the two ply bearers before soldering the pendulum on to it.
Now fasten a length of 1/64 in rubber, or similar, at the points indicated on the wings, to pass round the nose, just tight enough to keep the wings in the forward position. Some trial and error adjustments will be necessary to get the exact angle of the pendulum (that on the plan is as the prototype, but will differ slightly with each model). Add weight - in the form of solder - to the end of the pendulum until it is enough to release the wings when the model reaches a slightly nose-down position. It is not necessary to fly the job to find this, of course, the procedure being to hold it vertically, with wings folded and catch in position and gently turn it into its flying altitude. The pendulum should then drop, releasing the wings. Add weight to the nose (CG shown on plan) and trim in the ordinary way, with wings in flying position.
For catapult launch, fold the wings and hold the model vertically with the pendulum catch holding the wings bark. Launch just slightly forward of the vertical, so that the model drops over forwards, and not on its back. This is easily achieved with a little practice. Very good heights can be attained and hours of enjoyment can be had from experimenting with these rocket climb gliders. One wonders, too, if the principle might not be applied to Jetex or even rubber-powered models?"
Quote: "Glider plan and construction article attached. Stray Tupp by D.R. Hughes published in the December, 1950 issue of Model Aircraft found on www.rclibrary.co.uk There were no dimensions given on the plan, so it was assumed that the page in question was the standard 8-1/2 x 11 inch page size."
Direct submission to Outrzone.
Did we get something wrong with this plan? That happens sometimes. Help us make a correction
* Credit field
The Credit field in the Outerzone database is designed to recognise and credit the hard work done in scanning and digitally cleaning these vintage and old timer model aircraft plans to get them into a usable format. Currently, it is also used to credit people simply for uploading the plan to a forum on the internet. Which is not quite the same thing. This will change soon. Probably.
This model plan (like all plans on Outerzone) is supposedly scaled correctly and supposedly will print out nicely at the right size. But that doesn't always happen. If you are about to start building a model plane using this free plan, you are strongly advised to check the scaling very, very carefully before cutting any balsa wood.
© Outerzone, 2011-2018.
All content is free to download for personal use.
For non-personal use and/or publication: plans, photos, excerpts, links etc may be used, provided that full and clear credit is given to Outerzone with appropriate and specific direction to the original content i.e. a direct hyperlink back to the Outerzone source page.
Unauthorized use and/or duplication of this material without express and written permission from this site's owner is strictly prohibited. If we discover that content is being stolen, we will consider filing a formal DMCA notice.