A 1/3-ounce RC flyer

Model Airplane News, Jul 2000 by Revel, Guy

The lightest amateur-built, proportional RC plane ever flown during an indoor meet used to be called "2xRien," French for "twice nothing," but when its weight was further reduced, it was renamed "Moms que Rien" (less than nothing!). Flown at the Paris Model Show in April, the latest creation of the JMP team (Gerard Jumelin, Jean-Marie Piednoir and Jean-Yves Martin) is a 21.5-inch-span model that weighs only 1/3 ounce (8.9 grams!) and can fly for 2 minutes.

It's difficult to convey the excitement of seeing this very practical airplane with astonishingly nice flight characteristics in the air. With a wing loading of a mere 0.35 ounce per square foot, you bet it flies slowly! Part of the weight savings is owed to the use of a single Sanyo 50mAh battery that feeds both the radio and the motor, thanks to a special voltage converter designed and built by Jean-Yves Martin. (The steel case of the battery was stripped off and replaced with a sealed plastic bag-something I do not recommend that you do in your own workshop!) Because of the high current drain, the Sanyo Ni-Cd cell cannot be replaced with a lighter NiMH cell.

Just for the record, the team had considered using infrared control to save weight but decided to use a traditional FM radio link, which allowed 2xRien to fly with other models as well as at any indoor flight meet. In the quest to build the world's lightest RC model, Jean-Marie Piednoir designed a miniature, 4-channel receiver with a plug-in crystal that will soon be commercially available from WES-Technik. The new JMP receiver is definitely selective, as 2xRien has routinely flown with four or five other models in a small 40x40-foot hall without any sign of radio disturbance. For the latest, 8.9g Moins que Rien version, however, Jean-Marie stripped the receiver of many of its components. Although the bare receiver has poor selectivity and severely limited range, it weighs only 0.71 gram! The highfrequency ESC received the same treatment and now weighs only 0.3 gram.

Working at reducing weight, new ideas come every day. While Jean-Yves was flying the light model in front of thousands of spectators at the Paris Show, he quietly told me that the team has established a new challenge: they are already working on a sub-5g model!

For more information and video clips of the JMP team's models in flight, go to: ourworld.compuserve.com/homepages /jmquetin/jmpmoine.htm.

SPECIFICATIONS

Model: Mains que Rien (less than nothing")

Type: slow-fly monoplane

Construction: carbon fiber, Mylar covering

Wingspan: 21.25 in. (540mm)

Length: 16.54 in. (420mm)

Wing area: 127 sq. in. (8.2 sq. dm)

Weight: 0.31 oz. (8.9g)

Wing loading: 0.35 oz./sq. ft.

Drive system: coreless motor w/22.8:1 JYM gearbox, JMP 6.3x3.9 prop, JYM proportional magnetic actuators, JMP FM receiver and ESC, JYM voltage converter (0.6W, 0.9V to 11.4V in, regulated 5V out), one 50mAh Sanyo Ni-Cd cell.