Separator (oz15478)

About this Plan

Separator. Radio control single-channel aerobatic model.

Direct submission to Outerzone.

Quote: "The Separator is a rudder only contest airplane designed by Jim Houston for a variety of power plants, see also: Lil Sep (oz10934). Jim developed the design to be easily built for any size engine from .020 to .60 power. Using the magazine from the May 1968 issue of RCM, I used the dimensions for a .35 powered model and used the three views to provide the construction details. The tracing was handed off to Gene Rock for checks and 3D views.

Attached are the Jerry Klineburg RCM article, full size .PDF drawing, CAD file and .XLSX spreadsheet.

Best Regards,
Mike Denest
President
Vintage Radio Control Society
https://vintagercsociety.org/

Quote: "THE SEPARATOR SYSTEM. By Jerry Kleinberg. A LEAN, hard running Indian - with poised tomahawk - symbolizes the singular purpose of the SEPARATOR, the popular long lived rudder-only model. The grim Indian is often seen on the sides of these durable planes and this 'strictly business' figure seems to sum up the intent of Ben Harr and Charley Barren, the two San Antonio, Texas, RCers, who established the basic configuration of the SEPARATOR over ten years ago. Since then the model has continually proven functional in all its sizes and its success is reflected in the hundreds of copies built, the logging of thousands of flying hours, and scores of trophies SEPARATOR pilots have collected.

Considering it's a non-kit ship that has never been published - except for Jim Houston's special 24 in micro version Lil Sep (oz10934)seen in American Modeler several years ago - the SEPARATOR'S record is especially notable. Included here in tabulated form are several sizes currently being flown. The 6 foot Super and the 9 foot Giant aren't shown since they've been placed among the treasury of memories where tube receivers with 4 oz relays along with ground-based transmitters keep such aerial Cadillac’s company.

The SEPARATOR, as evolved, is not another airframe design, but is one that embodies a force arrangement and trim system intended to satisfy the particular flight requirements of rudder-only planes. Specifically, the competition sizes - the 48 and 60 inch varieties - have quick pitch reaction while retaining penetration qualities in winds to a stiff 35 mph. However, they loop readily in calm wind or in hot muggy air when the pressure-altitude reads 6000 feet and more. Control and acrobatic ability is achieved through use of an original 16% wing section (designed about 5 years ago) and a trim arrangement that includes:

A 25% CG location.
As much as 9° decalage with -7° on the horizontal, stab and 2° on the wing.
Up to 5° engine up-thrust.

These values result in a 'medium' trimmed Class I aircraft when compared with Milt Boone's 'light' trimmed CHARGER and Jackie Gardner's 'heavy' trimmed PENETRATOR. An important consideration is an adequate wing loading to satisfy maneuvering factors and to give the flight a sufficient measure of grace. For this reason not less than a 25 oz. wing loading per sq. foot is sought. (Somehow, Chuck Cunningham's formula - The Secret, R/CM Mar 1966 - doesn't compute here. Like the bumble bee, the SEPARATOR just flies on.) Significantly, engine power must be high to handle the weight and pro-vide enough excess power to produce a con-trolled positive pitch force vector induced by the upward angling of the engine.

This then, is the SEPARATOR SYSTEM - a short tail moment, moderate nose moment, a large decalage angle (see Zaic's Circular Airflow Theory), a 'flying' fuselage (that's a reason for the fuselage's extra width and height and its square cross-section), high power loading and up-thrust, and a thick, late breaking wing section to carry a high wing loading. Surprisingly, the contest sizes easily make good trainers and sport planes since stability is high - just take it easy with the power and use mini-mum rudder throw. With its large capacity and versatility, any radio system may be used; they've all been used successfully in the SEPARATOR."

Supplementary file notes

Article.
Design Chart (xlsx, zipfile).

CAD file

This plan is available for download in CAD format.

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