Gambler-AG
Wingspan: 50 in
Chord: 6 in
Length: 31.5 in
AUW: 6.6 oz
Wing loading: 3.7 oz/sq ft

Gambler-AG by Wright Brothers RC

Gambler-AG in flight

The Gambler-AG is a two-channel DLG (Discus Launch Glider) designed and marketed by Allan Wright of Wright Brothers RC. The Gambler-AG has a structure of built-up balsa and composite reinforcement. It is incredibly light (mine came out under 6 ounces), but strong enough to withstand an aggressive discus launch. The "-AG" part of the name indicates that it uses an AG-series airfoil, rather than the Selig airfoil of its predecessor, the Gambler+.

Gambler catch

The radio equipment used in this Gambler weighs 50g (1.8 oz):

All-up weight (AUW) of the completed airplane is 169g (5.96 oz).


Gambler-AG in flight Gambler-AG on grass Sharon with Gambler-AG

The Gambler's maiden flight was on 2008-05-06. Fifteen minutes after its first discus launch, the plane was specked out. Quite a nice flier!

Here is a short flight video.

Build log

I bought this Gambler-AG kit in early January of 2008, and started building it in mid-April. Construction took 32 hours over about two weeks. (It should have taken around 15–20 hours, but I'm a slow builder.)

I built this airplane with white glue (Titebond III), which was a pleasant change from the usual CA (cyanoacrylate) adhesive. White glue is easier to sand, and weighs less when dry. As a bonus, this was the first balsa plane I've built that I haven't glued myself to during construction.

Attaching D-tube sheeting with CA is usually a mess. Since I was building with white glue, I used the old "iron-on white glue" trick. It worked like a champ!

The trickiest part of building the Gambler was shaping the trailing edge of the wing. The TE must taper from front to back to follow the airfoil contour. Unfortunately, to reduce the number of sheets of balsa needed to produce the kit, the TE pieces are laser-cut from a sheet that's about twice as thick as the thickest part of the TE, so a lot of balsa must be removed to get the right shape. To do the shaping, the wing sections were securely taped to a metal ruler on the edge of the workbench, with more masking tape protecting the tops of the ribs. A half an hour or so with a razor plane, and another half an hour with sandpaper, resulted in the proper shape.

Here's how the construction time was spent:

2008-04-19: Assemble fuselage bottom, sides, and formers. Attach boom. (2 hours)

2008-04-20: Sheet fuselage top, add servo & battery hatches. Laminate nose block, attach, and sand to shape. Reinforce fuselage with carbon fiber strips. Laminate fiberglass to fuselage with finishing resin. (4 hours)

2008-04-21: Frame up center, left, and right wing panels. (4 hours)

2008-04-22: Mount wing locater pin in leading edge. Attach lower D-box sheeting to all three wing panels. (3 hours)

2008-04-23: Attach top D-box sheeting to center wing panel. (0.5 hours)

2008-04-24: Add D-box sheeting to tip panels. Plane and sand trailing edges. Join wing panels. (2.5 hours)

2008-04-26: Sheet center section of wing. Reinforce wing with carbon fiber tape on top and bottom of spar, bottom of leading edge. Wrap polyhedral joints with Kevlar thread soaked with CA. Weight of wing ready to cover: 56g (2.0 oz). (3 hours)

2008-04-27: Fiberglass servo and battery hatches. Reinforce fin and elevator with carbon fiber strips. Attach fin to boom. Shape stab mount, attach stab to boom. Reinforce fin and stab joints with Kevlar patches. Weight of airframe minus covering and radio gear: 93g (3.3 oz). (4 hours)

2008-05-01: Reinforce wing leading edge polyhedral breaks with carbon fiber. Cover tailfeathers with Ultracote Lite. Grind slot in boom for elevator pushrod. Epoxy elevator control horn in place. (3 hours)

2008-05-03: Cover wing with UltraCote Lite. (3 hours)

2008-05-04: Install pushrods, servos, receiver, BEC, and battery. (3 hours)

Some weights recorded during the build:

Some construction images:

Fuselage construction Basic fuselage completed Carbon tow reinforcement on fuselage Glassing the fuselage Glassing the fuselage Center wing panel Left wing panel Right wing panel Wing locater pin Wing bones, unattached Wing joining Wing joining Wing and fuselage Kevlar thread reinforcement at polyhedral joint Yes, it's a Gambler-AG Fin w/Kevlar patch Attaching the stab Airframe on scale 93g -- not bad Tailfeathers covered Elevator control horn Gambler-AG on bench Guts Guts Battle damage to D-box Repair to D-box sheeting