Toki Doki (oz11831)

About this Plan

Toki Doki. Radio control slope soarer model.

Quote: "How you can modify the Jetco 72 Nordic for truly magnificent soaring. Toki Doki, by Dale Willoughby.

STAND ON THE EDGE of a sandy cliff with a cool breeze blowing in from the ocean; a brand new six-channel transmitter in hand, then launch this reliable, well proven, slope soaring glider for the very best in radio controlled flying! No props, starting batteries and noisy, messy engine to contend with. Just fly and fly!

The designer of this modified version of Frank Ehling's Nordic 72 kit by Jetco may be slightly biased, but he turned to RC slope soaring after 30 years building all kinds of models, even microfilm, carried on as much as service life in the US Marine Corps would permit. I've built and flown models in China, Japan, Okinawa and Korea, as well as on both the East and West coasts of United States, and Hawaii. it was while in Virginia that I began to fly radio control power models in 1959, and built my first RC glider in which I flew on the golf course at the Naval Shipyard in Portsmouth.

On hot summer days, thermals were abundant, generated by hot cement areas surrounding the golf course, and flights of five to six minutes were common, using a 200-foot towline. This same glider, a Bill Dean Nordic A/2 configuration, was flown at Hughes Hill near Santa Monica, Calif, while I was on my way to Japan, and was the basis of the article 'Slope Soaring is Fun' published in the March 1960 issue of Flying Models.

By way of explanation, I use the words 'glider' and 'slope soarer' interchangeably, whereas in the strictest sense a glider can do little but to descend from the altitude from whence released, whereas a soarer or sailplane is capable of maintaining and gaining altitude after release. Likewise, 'slope soaring' and 'ridge soaring' are interchangeable. However, when I use 'ridge' I picture a razor-back hill in the midst of a mountainous chain, but to me 'slope' indicates a gentle incline, with a nearly level top.

Frank Ehling, who designed this good sturdy glider for FAI Nordic-class flying, must have had RC equipment in mind when he allowed for 5 ounces of weight in the nose. By widening the nose a bit and changing the fuselage shape from a 'V' to a rectangular cross section: using the full-sized parts shown on the plan: building a new swept tail with a balanced rudder, and installing your favorite radio equipment, your Nordic glider will give unmatched performance on any slope and will thermal soar.

Weight of the second test model was kept to 25 ounces, even with a fiberglassed nose section, for a wing loading of 8.3 oz/sq ft. We used the new Kraft Custom Six receiver driving a Kraft Servo. Power pack was a Medco PM 2.5-6V, so the equipment totalled about 10 ounces, the fuselage and stab about 9 ounces, and the wing 6 ounces. Of course, single channel equipment can be used, with an escapement or servo, and a lighter wing loading achieved. But I prefer to fly with reeds, because I am sure of getting the command I want from them.

The first model used a Kraft 10 receiver with DEAC 225 nah power pack, and a Transmite servo with equal success. he reason for changing to the Kraft servo was to determine through actual tests, the comparable battery life, this in preparation for an assault on the world's RC Glider duration, distance and altitude records. Phil Kraft says the motor used in fhe Kraft servo draws only 35-40 mah while running, which is a bench test figure. This drain rate goes up when there is a bind in the pushrod, or other friction is present.

Most readers interested in building this RC version of the Jetco Nordic 72 can pick up a kit for $4.95. At the same time, buy two sheets of 1/16 x 3 x 36 in hard balsa sheet, and check over your scrap box for the necessary hardware for the RC installation. The first step is to cut out the portion of the keel as shown to allow for space for the receiver, power pack and servo. Next, from the 1/16 hard sheet cut the bottom portion of the fuselage. Referring to the plans, build the crutch right over the plans as modified. This widens the fuselage to 2-3/4 in at the widest point under the leading edge of the wing. Make sure there is sufficient room for the servo. On number one RC Nordic the Transmitter was mounted on end, and on number two, the Kraft Servo was mounted flat, both in line with the fuselage so that the pushrod wire required no bending.

Install the keel as in Step #2. using a triangle to insure correct alignment. Now install new formers F-1, F-2, F-4 and F-5. Note that F-1, F-2 and F-4 are cut from 3/16 balsa removed from the keel. Aft of F-5, instead of using the tri-angular die-cut balsa, use 1/16 x 3/16 hard balsa, and install after the 3/32 x 3/16 cap strip has dried for several hours. This feature permits the 1/2 in-diameter wooden dowel, used for the rudder pushrod, to pass freely through the fuselage..."

Toki Doki, Grid Leaks, January/February 1965.

Direct submission to Outerzone.

Supplementary file notes

Article pages, thanks to RFJ.

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