Mini Thermalist (oz3484)

About this Plan

Mini Thermalist. Free flight glider.

The original Thermalist (oz11429) was first published in Aeromodeller 1948. This here is a reduced size, later version.

Quote: "THIS IS A HALF SIZED version of R Minney's enormous vintage glider and it makes a very handy and attractive sports model. Construction is very simple and can be completed in a week of evenings. No special parts are needed, such as a fishing rod blank and since it will be towed straight up and off, a fuse DT is perfectly practical and cheap and costs little!

The recent beginners series by Trevor Faulkner covered just about all the points you will encounter on this model, but I shall mention one or two features.

Fuselage: Having built two sides, join them with F2 and F3 and add the spacers between. Then draw together at the tail, tapering the ends so that the width here is 3/16 in to merge with the fin, and then add F1. Bend a shallow angle into the wing joiner and epoxy to F2 - this is to prevent the wings from drooping slightly (the inner panels are flat).

Wings: The wing joiner passes directly through the ply ribs and a 1/8in. peg fixes the incidence. A band passing between hooks on the wing roots holds the wings in place. The drawback with this method of wing mounting, is that if the model glides into an obstruction the wing cannot knock-off, and may suffer damage. If this worries you a thin dural tongue could be used. Before covering, assemble the model and put plasticene inside the nose to bring the balance point about 1/4 in in front of the position shown. Cover with lightweight Modelspan and give three coats of dope.

Trimming: Packing the tailplane is not very satisfactory since it spoils the fin/sub-fin junction this is what I did: before fitting the wing pegs, use pins in the fuselage above and below the wing trailing edge and vary the wing incidence for trim. When the glide is OK fit the pegs, and fine tune the glide with tail ballast. The autorudder seems small, but is perfectly adequate."

Supplementary file notes

Article page, text and pics.

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