Sopwith Pup oz1570


Sopwith Pup - plan thumbnail image

Sopwith Pup - completed model photo

This plan was found online 10/08/2011 at:
Outerzone planID: oz1570 | Filesize: 904KB | Format: • PDFbitmap | Credit*: algy2, DBHL, theshadow


About this Plan

Sopwith Pup - Free flight scale gas model, for diesel motors up to 1cc. WWI biplane fighter. Pendulum controlled rudder shown, and sprung undercarriage. Scale is 1/8.

Quote: "Neither gone nor forgotten this great aircraft survives the ravages of time - a Pup still flies today. And now, in many places the atmosphere of the 'old days' will again be recaptured by the flying of this superb power model whose flight faithfully follows that of the original machine.

Following in the tradition of Bagley and his popular Bishop's Nieuport I7C, the model 'Pup' described in the pages of this article is equipped with the same built-in stability device, the automatic 'pendulum' rudder which makes light of one of the most difficult features of true scale model design.

Powered with a Frog 100 diesel, but will fly with any engine of similar capacity, it was tested with a .9cc Clan engine which proved to be lacking in sufficient power. Simplicity and strength were the keynotes in the design, the undercarriage being sprung in the true scale fashion ie with rubber band shock absorbers. The wings and engine mounting can knock off in the event of a crash.

Fuselage. The fuselage is built as a conical slab-sided box structure of 1/8 inch square hard balsa. Commence by building the two sides flat on the plan, afterwards joining them together with the various top formers, cross spacers, etc. Then bend the centre section struts to the shape shown on the plan from 18 swg wire and bind in place. Next, add the side formers, stringers and sheet. The cowling is carved out of hard balsa in two halves the top half being plugged into the lower half which is cemented to the 1/8 inch ply front former, which is in turn held to the fuselage by means of strong rubber bands. The engine is bolted to this former, 5 degree sidethrust being obtained by packing with washers.

Wings. First pin down TE and LE to the plan. The mainspars will have to be packed up with pieces of sheet to allow for the undercamber, when this has been done add the ribs, then build up the tips with 1/16 x 3/16 inch hard balsa, when dry steam 1/16 inch square bamboo to shape and cement on. Next, make the 20 swg wire strut lugs to shape shown on plan, then bind and cement firmly in place at an angle allowing for the stagger and dihedral of the wings..."

Update 12/09/2018: Replaced this plan with a clearer copy, thanks to DBHL, theshadow.

Scan from DBHL, cleanup by theshadow.

ref DBHL-7111.

Direct submission to Outerzone.

Supplementary files

Previous scan version.


Did we get something wrong with this plan? That happens sometimes. Help us make a correction


oz1570 datafile

Sopwith Pup  
by GE Fisher
from Aeromodeller (ref:FSP-305)
December 1948 
40in span
Tags: Scale IC F/F Biplane Military Fighter
all formers complete :)
got article :)


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User comments

The u/c fairings wont work the way they are drawn as the cowl/engine mount is in the way. They would have to be shorter at the top than shown.
anon - 16/07/2017
Looking at the front section it's ok because legs fairings are out of the cowl circle contour. The side fuselage show superimposed fairings to the engine cowl due to the perspective.
Pit - 17/07/2017
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* 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.


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