Mini Kema (oz10019)

About this Plan

Mini Kema. Radio control sailplane.

Quote: "MINI-KEMA. KG HUMBER provides the answer to many requests for a semi-scale slope soaring R/C glider. 84 in wingspan, for 4 channel controls.

THIS ELEGANT GLIDER is the smallest of a long line of multi-channel slope soarers which have been developed in the Isle of Wight. Purchase of a transistorised relayless receiver brought the realisation that nine foot soarers are no longer necessary provided that an 84 in model could cope with weather conditions. The only way to prove such a point is-to try, so KG Humber designed a model as small as he could for the gear concerned. As it happened, performance was excellent right from the start.

Mini Kema turns very well without being dangerous and its looping radius is very tight (estimated at only 15 ft). It has been flown successfully in winds ranging 0-20 mph. Due to the size, no trim servo is fitted. Minor trim adjustments are taken up by small packing pieces between fin and fin fairing which moves the elevator a small amount. 3/32 in of packing copes with the difference between a 20 mph wind and a light breeze.

Constructionally the model is quite straightforward and should present few problems to anyone who has built a couple of models or so. The designer always starts with wing ribs first and then builds the pair of wing panels. Secret of the wing construction is the light but strong full depth spruce spar. This is cut from 1/8 in sheet spruce notched with a hacksaw blade for ribs. The wing boxes are made of 1/16 ply sides and 1/4 x 3/16 spruce top and bottoms bound with thread and well cemented to the spar at the root. This is most important as the box takes quite a hefty knock in a heavy landing. Leading and trailing edges are also notched with a hacksaw (just the right thickness for ribs). The top of the leading edge is sheeted with 3/32 flexible stock (not quarter grain), also those first two rib bays on the top side and underneath. The rest of the ribs are capped with scrap 3/32 x 1/4 soft balsa, this is important as a wide rib spacing is employed.

Tailplane structure is straightforward. Leading and trailing edges are cut out of soft 1/2 in sheet. Ribs are cut as simple rough rectangles glued up and then shaped with a razor plane and glasspaper to a symmetrical section. The elevator halves are joined with 3/16 in dowel and sanded to section, then hinged with tape to the tailplane..."

Mini Kema, Aeromodeller, November 1964.

Note this is a low resolution plan.

Direct submission to Outerzone.

Supplementary file notes

Article pages, thanks to RFJ.

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