MODEL AEROPLANE NOTES and General Hobbicrafts

Auckland Star, Volume LXIX, Issue 280, 26 November 1938, Page 3 (Supplement)

MODEL AEROPLANE NOTES and General Hobbicrafts

by poper;lly

EDWARD LIDGUARD'S "FOO" His Favourite Knock-about Experimental Model. I noticed recently a set of sketches of an all-baWi fuselage model, which though, as the designer says, is "not pretty exactly," has all the charaeter-i-tics required in a model of this type. It is reputed to have stood up to steady Hying for two years and then finally soared away to lie lost "ont-of-flight" after a recorded flight of six minute*. Easy to build, up to weight rule and a reasonably large model without Iteing cumbersome, I thought that the details would ap|H>al to you.

Here are the constructional details that will help you to build it, and I can advise you to do it, if only on the reputation of the designer, who is one of America's foremost model fivers.

Fuselage: This in made of medium grade balsa l-ltiin sheet, sides and top and bottom being cut to shape after you have cut out cardboard templates iu order to get the correct shape. Xote that 1-10 sij. balsa stringers are inserted inside the corner joints, the outer edge being rounded off afterwards. Use plenty of cement, pinning the joints

temporarily during construction. It is advisable to give the whole of the inside a coat of banana oil before assembly. Do not use dope, as this will have a tendency to warp an<l twist the balsa veneer. All wire fittings are made of 22 swg wire. When setting the rear rubber hook in place some rubber tube or spaghetti over it before assembly of the fuselage. Slits in the sides, top and bottom are made to take the elevator and rudder. The propeller is made from a JOin Kedic-ut and a freewheeler and ball bearing washer is fitted.

All the balsa ]*arts so far mentioned are made in the normal fashion by cutting out to shape with a razor blade and sanding smooth with very fine glasspaj>er. Apply a good coat of banana oil over all parts and then sand off the roughness (mused by the raising of the hairs in the wood. This attention to detail will not only give looks to the finished model, but the smoother surface will naturally improve the flight i-apabilities.

The wing is rather unconventional and oilers the only slight difficulty in the whole of the construction. It is made entirely of sheet balsa. Four 24in by 2 by 1-32 balsa sheets are used, two 2in sheets l>eing cemented together on edge in order to <;et the required width of Wood. The lower camber is cemented to the ribs first, using small pins for getting a good strong jointing. The pins are of course taken out afterwards.

The trailing edge is obtained by sanding both sheets to a thin wedge shape, the undercamber slightly overlapping. The leading edge is cemented into place and rounded off to the shape shown.

Here are the adjustments. The wing has two degrees positive incidence (to the rubber ba-se line); right aileron Jin down, left aileron Jin up. Elevator has one degree negative incidence. The rudders are warped approximately l-16in to the right, but varies with individual models. Xote the downthrust shown on the drawing. There is l-32in right side thrust given. The motor consists of 24 strands of Jin brown rubber. Remember that brown rubber is much more delicate to use than the ordinary black. It

must never be fully wound until you have completed a dozen or more quarter, third and half-wind flights. It must be lubricated liberally, as it seems to soak up the first application of rubber lubricant. The cost of all the materials, including freewheeler and ball thrust race, will be approximately 7/.