Dymond Modelsports Robbe Concorde

Model Airplane News, Apr 2003 by Garwood, Dave

FLIGHT TEST

Hot electric performance

The Robbe Concorde grabbed my attention the moment I saw It In the "hotliners" section of the Dymond Modelsports website. Its sleek appearance and promise of high-speed performance made me decide, "This Is my next plane." It has a molded airframe and colorful finish, so you need only hinge the control surfaces, Install the control linkages and wire the motor and speed control. On top of this, the Concorde is an excellent flyer whose twin motors help It cover a lot of sky quickly. It's also capable of some impressive aerobatics.

The Concorde comes with a well-engineered, injection-molded-- foam airframe and control surfaces; precut Depron foam vertical fin and fuselage strake parts; a large decal sheet with both British Airways and Air France markings; two Speed 400 motors and pusher propeller assemblies; control-surface linkage wires, tubes, horns and small hardware; six radio-frequency noise-suppression capacitors; motor wire; and a photo-illustrated, 24-page construction guide and flight-prep instructions.

CONSTRUCTION

Construction consists mainly of gluing together molded-- foam parts of the airframe, cutting off and hinging molded aileron and elevator parts and installing and wiring the propulsion and RC systems. The work goes smoothly and easily, and if you plan for periods of overnight drying and curing, it can be completed in five, 1- to 2-hour evening sessions.

A note on choosing adhesives: if I understand the Robbe instructions, the factory calls for CA and epoxy to assemble the kit. My experience with Goop glue on previous EPP-- foam kits has led me to trust this tough, sticky glue to attach airframe parts, install control cables and hold wires in place. I have no reason to think that CA glue won't work, but I know cured CA is brittle while Goop is flexible and, in my experience, flexible adhesives resist landing damage better. Per the instructions, I used epoxy for the hinges and Depron foam parts (Goop will melt Depron foam).

The Dymond Modelsports website recommends the Hitec Focus SS III radio for this model, so I ordered one. The single-- stick SS III is a perfect match for a delta-wing electric model, as it can mix aileron and elevator channels and has a third slider switch channel for motor speed control. It's very inexpensive for a transmitter that has a mixing function.

IN THE WORKSHOP

All righty then. Got your tools and materials? Understand the instructions? Familiar with the order of battle for building? Then let's build the Concorde.

* Evening 1. Glue the nose cone and tail cone halves together with Goop, keeping the parts aligned with masking tape. Cut the elevators and ailerons away from the molded wing with a sharp hobby knife, and clean up the edges with sandpaper. Assemble the hinges and drill holes to receive the hinge points in the control surfaces. A 7/64-inch-diameter drill bit works if you don't have the 2mm drill bit that the instructions specify. Mount the hinges in the control surfaces with epoxy. The kit instructions mention an excellent procedure for aligning the hinge angles: bend the assembled hinge points 90 degrees, and point them upward while one side cures. Set these assemblies aside to cure overnight. a Evening 2. Drill holes for the hinge points in the trailing edge of the wing, and install them with epoxy. Glue the nose cone to the front of the fuselage with Goop adhesive, holding it in place with masking tape. Set it aside to let the epoxy and Goop cure overnight. Skip ahead in the instructions, and solder the radio noise-suppression capacitors and the power leads to the motors.

* Evening 3. Install the control cables and servos. I mounted a pair of Futaba S-3003 standard servos, which fit perfectly into the molded pockets, with a small smear of Goop on each side of the servo.

Though the control wires slide easily inside their tubes on the bench, fitting them into the serpentine slots that are molded into the wings causes them to generate enough friction that I was glad I'd decided to mix aileron and elevator function in the transmitter, and thus installed only two control cables instead of four. If you use a transmitter that doesn't have elevon mixing, and you need to install four control cables, consider using a light, flexible, braided control cable, such as Sullivan no. 507, to reduce friction loads on the servos. Install the control cables with Goop or CA, hold them in place with masking tape strips, and let the cable installation set up overnight.

* Evening 4. Complete the wiring harness, including the ESC, and install the wiring in the airframe. Plenty of high-current wire is included in the kit, and the wiring instructions are crystal clear. The receiver is too far away for the stock D-35 ESC lead to reach, so you'll need a 12-inch extension cable. You may also cut off the short receiver lead and solder on a portion of a heavy-duty aileron extension cable, such as Expert Electronics no. EXRA 130, to eliminate a connector.

I used Goop in several spots to hold the wires in their slots. Before you quit for the night, glue the tail cone and ESC motor-- controller hatch into place with Goop, secure the parts in place with masking tape while the glue dries, and mount the control horns with epoxy.