Wasp (oz5300)

About this Plan

Wigdor Wasp. Free flight gas model. Wingspan 40 in, for Elf 2.3 cc ignition engine.

Quote: "Hi, Another one for the website. This is the Wasp of L S Wigdor from the Aeromodeller, April 1938. I've attached the article and plan separately. The plan was the centre page spread and therefore not full size. Anyone wanting to build the model really accurately should re-draw it to the dimensions given on the plan (as printed in the magazine it's not perfectly to scale in each direction though the wing and tail sections are correct and full size). However, if you enlarge the plan by 300% then it's pretty damned close and would will be certainly be sufficient for me if and when I built one for a Mills 75. Keep up the brilliant work. Cheers,"

Direct submission to Outerzone.

Update 1/11/2025: Added further article, found on RCGroups thanks to MordecaiMurphy. This is a column by Alex Imrie from Aeromodeller, July 1981.

Quote: "Vintage Corner by Alex lmrie, President, SAM 35 UK (From Aeromodeller, July 1981).

Wasp. Various vintage modellers have offered help with material for this column, and I am sure that many fine contributions will be received in due course. However, I am pleased to report that the most active response has come from original vintage modelers who are still very much with the hobby today. This month, LS Wigdor, who has been at the game for almost 50 years, provides the source.

In 1937, he received a small Elf petrol engine from his penfriend Elbert J Weathers, in California. This engine, although of limited power for its 2.3 cc capacity, was a smooth-running sand-cast beauty, and had an ignition coil that would work satisfactorily on only 1.5 volts.

A feature of this engine was its very great fuel economy. It could drive the 12 x 6 Chauviere-type propellor supplied with the engine at 3500rpm for 40 minutes on one ounce of fuel!

Other features not usually found on so small an engine were a float chamber carburetor, adjustable and completely enclosed contact breaker points at the rear of the engine, three piston rings and a 'full-size' type of airscrew hub which, in addition to the normal crankshaft nut, also used four bolts which passed through the propellor into tapped holes in the drive washer.

However, although these features were most impressive, the engine's light weight (4 oz bare) coupled with its single cell flight battery were even more impressive and simply called out for a really small petrol model.

LS Wigdor had already built petrol models powered by both the Brown Jr and the Baby Cyclone engines. These were mainly large machines of around 8 ft wingspan. An attempt to fit these engines into a 50-inch span model had not been overly successful and, wanting a small model, he now enthusiastically started a design for the Elf.

The machine that emerged in the summer of 1937 was named 'Wasp' and had a parasol-mounted wing of 39.5 in span. It resembled the Kovel-Grant layout, but had the spidery wire undercarriage of a rubber-driven model. The long undercarriage was needed to provide clearance for the 12 in propellor. Replicas usually use smaller propellors, but the length of the undercarriage should not be reduced since this will change the whole appearance of the model. The reversed rake tip on the tailfin was a typical Wigdor trademark.

The Elf was fitted inverted, and booster battery contacts, modified clock timer, and access panel for the flight battery were located on the top of the rear fuselage.

Covered with bamboo paper, treated with full strength Titanine tautening dope and finished in aluminum, the model weighed 17 oz. This light weight resulted in slow flight speeds of between 15 and 20 mph. The model was stable and performed best in fairly tight circling flight, being quite sensitive to adjustments of the large rudder tab.

The Elf engine was responsible for quite a spate of small power designs in the United States - the better known being Miss San Diego (oz3569) by Joe Weathers at 48 in span, Cavu (oz1081) by Ken Willard at 44 in span, and the Abzug S-4 (oz8934) by Malcolm J Abzug at 36 in span. ln England, the attraction of such a small power model as the Wasp led to a description and plans appearing in Aeromodeller magazine during 1938. The Wasp drawing, which was originally a double-page layout in the larger pre-war Aeromodeller, is reproduced here as a single page. The dimensions are easy to read and airfoil sections are given full-size, so it should be a simple matter for enthusiasts to produce a Wasp replica. The original wheels were turned balsa doughnuts.

In recent years, at least two Wasps have been flying regularly. One built by David Baker has given excellent service powered by an elderly FROG 100 diesel. This model had an unusually slow glide, being covered with silkspan and lacking the usual weighty spark ignition components. My model was built in 1974 and powered by a FROG 1.75 cc petrol engine. Replicas of this design can be powered by any of the popular small diesels of 1 cc or less displacement with the Mills .75cc possibly being the best power unit."

Supplementary file notes

Article.
Article (1981).

Corrections?

Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction