Fox (oz12723)

About this Plan

Frog Fox. Free flight power model. Wingspan 40 in, wing area 235 sq in, for Frog 100 Diesel or Frog 160 Red Glow engine.

Direct submission to Outerzone.

Quote: "Frog Fox. 40 inch span high performance power duration model. Building and Flying instructions:

This design has been subjected to a thorough testing during the past months, and has a proven performance of a high order, combined with a very robust construction. The streamlined monocoque fuselage is unique, being almost indestructible under normal conditions, whilst the wing is of one-piece, rigid design, and will detach itself under impact. A high-lift section is employed, giving a low sinking speed in gliding. A flip-up tail dethermaliser is embodied in the construction, and is very effective in limiting the length of flight.

Designed primarily for the Frog 100, 150 or 160, it is adaptable to any other engine of similar capacity.

An outstanding feature of this kit is that most of the parts are pre-cut, and numbered for easy reference with the full-size drawing. It is only necessary for the parts to be eased carefully from the panels with the help of a razor blade, and then assembled over the plan.

Before commencing, lay a sheet of greaseproof or tracing paper over it, to prevent the cement sticking.

Fuselage: This is composed of two half-shells of reinforced balsa 1 and 2, which are supplied ready formed to shape with bulkheads 3, 4, 5, 8, 4a and 5a fixed in place. When these are joined together, they form a very strong and rigid unit.

First take the parts to make the wing platform 9, 10 and 11, and cement these together as shown in fig.1. Then cement together parts 12 and 12a to form the pylon, fig.2, followed by the 1/4 in sq strips 13. These are fixed to the upper edge to make a support for the platform, and shaped as shown in fig.3. Cement the platform into place, following the curve of the pylon, and obtain the correct dihedral angle with the aid of a piece of scrap wood or card shaped as in fig.3. When these are set, cement the pylon to the upper fuselage half, in the slot provided, see fig.4, making sure it is perfectly upright. See fig.6.

Next assemble the U/C 6, fig.5, to the lower fuselage half, using the small block 7 well-cemented in place to hold it. Recess the wire into block 3, so that it is flush with the front face.

If a 'timer' is to be used, it must be fitted at this stage, with bulkhead 14 (also referred to as bulkhead 3 in plan, and 13 in cross-section drawing). Fit a piece of ply to the back of this bulkhead, and make a metal bracket to take an 'Elmic' timer. For a 'Snip' pattern, a hole will have to be cut in bulkhead 14, and a support piece 15a fitted in place after. Sandpaper the bulkhead to fit the fuselage when assembled, as it is slightly oversize, and cement it into place. A hole or a slot will have to be made in the fuselage side, to take the timer arm as shown in plan and side views..."

Note this kit included a two-part ready-formed balsa monocoque fuselage, so any modern builder hoping to scratch-build from this plan will need some ingenuity to replicate the construction. None of the fuselage formers (and ony one main wing rib) are shown on the plan. If anyone can scan and submit the kit parts and formers, printwood etc, that would be great.

Update 24/02/2021: Added ribs file, thanks to BarryRawle.

Supplementary file notes

Instructions.
Ribs.

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