Bristol Brownie II (oz14724)

About this Plan

Bristol Brownie II. Radio control scale model. Wingspan 36-1/2 in. Scale is 1/10.

Quote: "1/10th scale, 36 in span model, designed by Dr Mike Hawkins. The Bristol Brownie MK II.

THERE IS SOMETHING ABOUT SMALL MODELS. Turn up at the club with your latest 40 to 120 powered masterpiece and few give it a glance. Mine, anyway. Bring a scale model with a 1cc diesel and immediately you have a crowd. What is it? Is it a kit? Has it flown? Tee nii aray khrap? After the hours of building it warms your heart, and not so many hours either, as small models really take much less time, besides providing a complete contrast in flying technique to the more usual high powered monsters.

At 1/10th scale, G-EBJM has a span of 36-1/2 in. The others had wings of different spans. I have kept to scale outline as much as possible but the bi-convex wing section has been changed to flat from the front spar back on the under surface. This enables the wing to be built flat on the plan and because of the taper of wing thickness, results in a comfortable 4° of washout. Indeed, I doubt if the model would have survived its first flight without it!

Construction: Wing: Build each panel flat on the board, using the template to set the angle of R1. Spars, leading and trailing edges, project about 1-1/4 in inside R1. With the tips packed up 2-1/2 in chamfer LE, TE and lower spars to be flat on the underside and add the joiners. I used cyanoacrylate for most jobs, which is a good way of getting attached to the model you are building. Trim and add the false ribs and sew the 14g undercarriage legs to the inside of R1 using a needle and thread followed by glue. Finally, sheet the centre section with soft 1/16 sheet. This is a little fiddly around the spars.

Fuselage: This is a basic 3/16 square box, with a nylon motor mount bolted to the front former. From the photographs of the original, I am not quite sure if the front fuselage is covered with ply or fabric. For the model, 0.4mm (1/64in) ply, provides strength where it is needed. Cut panels oversize and stain with a light wood dye such as 'teak' before trimming and gluing. Build a box for the tank with a drain hole through the former.

The upper cowl is from a thin piece of aluminium, annealed and curved with thumb and fingers. It is screwed to two small hardwood blocks stuck to F1. The lower cowl is from soft block. A worn out Cox 049 cylinder was screwed into a piece of ply and mounted on the left side. This enabled me to tell my friends that in view of the shortage of diesel fuel here, I had fitted a compound engine and could switch over to run on glo on the other cylinder. (I now have few friends.)

The tail is built up of strips cut from 1/8 sheet. Small pieces of mylar tape are used as hinges, slotted into the control surfaces and 1/16 ply is perfectly adequate for control horns... "

Bristol Brownie from R/C Scale Aircraft, December 1994.

Direct submission to Outerzone.

Supplementary file notes

Article pages, thanks to RFJ.

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