Radio Control: Soaring
Dan Pruss
Savage
Here are a couple of birds this month that are relatively new to the soaring scene. Actually, there are three of them; two are just of the same basic design. Those two are Savage and Son of Savage.
The handiwork of Mark Rebeck (San Juan Capistrano, CA), the Savage was primarily designed for slope flying. It is a simple, docile aileron-equipped sailplane intended as a good starter for pilots who have not flown an aileron-equipped glider before.
Specifications and features:
- Wingspan: 70 in.
- Flying weight: 2 lb
- Wing area: 650 sq. in.
- Wing loading: 7–8 oz. per sq. ft.
- Controls: ailerons and elevator only
- Airfoil: modified Eppler 374
- Kit includes: machine-cut balsa and plywood parts, complete hardware package, full-size rolled plans, instruction booklet, foam wing cores (balsa sheeting supplied)
The one-piece wing makes for simple construction, and the linkage for the flying stab is straightforward. Savage accepts radio gear from micro to full-size systems. Mark claims Savage is docile, has excellent penetration, and a wide speed range suitable for pilots new to this style of flying.
Kit price is $55; a glass-fuselage version will be available for $75.
For further information contact: Mark Rebeck, c/o California Slope Designs, 31932 Calle Winona, San Juan Capistrano, CA 92675. Phone: (714) 493-0843.
Son of Savage (SOS)
When one comes up with a three-fifths version of the same bird, it's naturally called Son of Savage. SOS is basically three-fifths the size of Savage but has a disproportionately longer tail moment and a larger rudder and horizontal stab.
Specifications and features:
- Wingspan: 42 in.
- Wing area: 233 sq. in.
- Ready-to-fly weight: 11½ oz.
- Wing panels: foam with 1/16-in. balsa covering
- Fuselage: balsa sides with 1/8-in. plywood doublers
- Controls: ailerons and elevator (ailerons about two-thirds the span of the wing)
- Radio: mini or micro gear
- Wing loading: about 7 oz/ft² (very light—similar to Whiffle Ball, rag dolls, foam bricks)
SOS is a great all-around plane for slope flying, hand launching, hi-start launches, thermalling, and general fun flying. A hard landing usually does little damage because of the light weight. Price: $35 for the ready-to-fly version; $45 for the kit which includes a fiberglass fuselage. Add $3 per kit for shipping.
For further information: Mark Rebeck, c/o California Slope Designs, 31932 Calle Winona, San Juan Capistrano, CA 92675. Phone: (714) 493-0843.
Oops! We forgot to identify these airfoils in last month’s column. Here they are: Eppler 180, Eppler 184, Eppler 220.
Synergy (South Bay Soaring Society)
Up in the Bay Area, the South Bay Soaring Society (SBSS) has produced a competitive sailplane called Synergy. The bird is the combined effort of Tom Strouth (designer), Rich Spicer (plug carver for the fiberglass fuselage molds), Brian Chan, and two-time USA F3B team flier Don Edberg.
At a glance Synergy looks like a cross between Dwight Holley’s Gobbler and Dr. Helmut Quabeck’s current Dohle. When designs are fine-tuned to contest rules, common features among winning designs will appear, but Synergy contains many clever details—especially in its linkages.
Design and control features:
- Controls: rudder, elevator, ailerons, and flaps
- Ailerons and flaps can be mixed to change camber or be controlled independently
- Flaps can be positioned from a few degrees above neutral to 90° down for landing
- Mylar strips on the leading edge of the flaps remain flush during normal flight; when flaps are down for landing the Mylar protrudes above the wing surface to prevent ballooning or pitching
- Camber settings: approximately −4°, 0°, and +4° (achieved mechanically via servo/linkage mixing so any five-channel radio can replicate the functions)
- Flaps and ailerons are 22% of the wing chord; ailerons and flaps taper proportionately with the wing
- Airfoil: Quabeck 10/2.5/9 (10% thickness at root, thinning to 9% at tip, 2.5% camber)
Linkage and servo installation:
- All five servos, receiver, and batteries are mounted on a single plywood board (1/8-in. base with layered plywood shaped to the fuselage interior)
- Mounts for servos, switch, receiver, and batteries are glued to this board; the assembly is secured from the bottom of the fuselage with four screws
- This layout absorbs jolt along the fuselage bottom and prevents formers from concentrating stress and breaking off in hard nose-first landings
- No wing-mounted servos: one servo inside the fuselage drives cranklike linkages into the flap roots; another servo drives both ailerons with detachable torque drives; another servo repositions the aileron/flap servos to change camber
Construction and specifications:
- Wing and stabs: foam cores covered with fiberglass using a vacuum-bag process (mold-like finish)
- Wingspan: 120 in.
- Root chord: 11 in.; tip chord: 8 in.
- Stab area: 10% of the wing area
- Tail volume: 0.36
- Overall length: 57 in.
- Empty weight: 11.2 lb; wing loading empty: 14 oz/ft²
- Ballast: up to 2 lb of No. 9 BB shot can be carried to increase wing loading to 18.2 oz/ft²
Synergy has flown well with gratifying results and won the South Bay Soaring Society's F3B design contest.
Good News / Bad News
Bad news: The annual Great Race, a major Midwest Sailplane event, has been cancelled this year due to flying site problems.
Good news: The Eastern Iowa Soaring Association is sponsoring a Cross Country Soaring meet at North Liberty, IA, on Memorial Day weekend (May 26–27, 1984). It will be run according to the new (1984–85) AMA rules as a Provisional event. If you have not received the new rule book by the time you read this, see the summary of the rules in the December 1982 issue of Model Aviation (page 109), Rules Proposal RC-84-27. The rules are much like the Great Race rules.
For further information contact:
- Terry Edmonds, Contest Director
- Address: 1 Lakeview Dr., Iowa City, IA 52240
- Phone (office): (319) 353-5665
- Phone (home): (319) 351-1517
Just to save you a trip to the dictionary: synergy is the effort whose total is greater than the combined efforts of the individuals. Sounds like the SBSS boys have come up with more than just a proper name. Good lift.
Dan Pruss 131 E. Pennington Ln. Plainfield, IL 60544
Transcribed from original scans by AI. Minor OCR errors may remain.
