Sea Nymph (oz1807)

About this Plan

Sea Nymph. Free flight seaplane, for Mills .75cc engine. Aeromodeller March 1954.

Quote: "Vic Smeed's flying-boat for small capacity engines.

Twelve building hours proved adequate to construct this little flying boat, due to the simplified hull construction, which combines efficiency with a very high strength/weight ratio. The total flying weight of 10-1/2 oz gives a wing loading of 7oz per sq. ft which ensures a reasonably low stalling speed with consequent quicker take-offs and easier 'landings'. Fitted with a Mills .75 in flat calm the model planes in three to four feet and is airborne anything between 25 and 40 feet, depending on the prop.

The hull sides, cut to the true outline shown, are first cemented to F3 and the remaining formers and the bow block inserted, using rubber bands and pins to cope with the slight twist in the sides. Soft, light material should be used throughout. The rear under-sheet must be cemented in before the heel can be drawn together and F4A placed. The sponson mainspar and TE should be slid in place before adding the keels and completing the under-side sheeting.

Install the pylon (the ply backing to F3 and F4 is to form a secure anchorage) and the 1/8 in sheet cabin pieces and braces, then sheet the after hull top. Build on and sheet the sponsons, butting the covering against the hull sides, and sheet the remainder of the hull top. The motor bearers are glued direct to the pylon, which offsets the thrust line slightly, giving, in effect, slight right thrust. An alternative mount is given on the plan. Sheet the pylon sides and add wing and tail platforms, dowels, and other details. Sand all over, but do not round the corners along the chines.

Cover the whole model with lightweight Model-span or rag tissue, and apply two coats of clear dope and one flowing coat of banana oil. Double covering and two coats of banana oil can be used if really rough handling is expected. Add the three-piece cabin celluloid and the motor, and a little colour trim if desired.

Flying is not difficult, but the thrust line is fairly critical and may need slight adjustment for different motors and/or airscrews. 8 B.A. bolts in oversize holes allow sufficient adjustment. Check the model's balance (slightly behind rear spar, as shown) and test glide over long grass - no undercarriage, remember! Any drastic alteration (if your sheet was iron-hard for instance) should be made with ballast, but small incidence changes are permissible. Once glide is fair, launch under low power, increasing gradually and making normal thrust adjustments..."

Update 04/12/2015: Replaced this plan with a clearer copy (patterned background removed) thanks to TonyP.

Supplementary file notes

Article.
Previous scan version.

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