Sabre 2015 - 25th Anniversary
SABRE is a simple lightweight thermal soaring glider with an excellent performance. It is simple to build and its rectangular wing guarantees benign stall characteristics. It’s a versatile model - the prototype has even been used to take aerial video of Milton Keynes using a mini digital camera - see below. Sabre uses standard size servos and radio gear operating rudder and elevator. Purchase the Sabre Plan RC1626 from MyHobbyStore.
Above: Sabre prototype 1
Abbove: "Closed-loop" control system modification worked extremely well in improving lateral control.
Plans for the Sabre were published in RCM&E magazine in 1990. In 2011, to mark the 21st anniversary of publication, Sabre prototype number one was overhauled and converted to electric power.
The conversion is relatively straight forward. An aperture is cut in the balsa nose block as far back as the first fuselage former. A 2.5mm plywood firewall is glued to the former such that it gives the motor around 3 degrees down-thrust relative to the wing chord line. The motor is screwed directly to the firewall.
The equipment within the radio bay is repositioned. The servos are moved back and the second fuselage former is cut so that a 1200mAh 3s LiPo battery and speed controller can be accommodated. 2.5mm packing under the tailplane leading edge reduces longitudinal dihedral and completes the conversion.