SideWinder II
Wingspan: 1.5m (59.1 in)
Wing area: approx 340 sq in
AUW: 9–11 oz
Wing loading: approx 4.2 oz/sq ft

Polecat Aero SideWinder II

SideWinder II

The SideWinder II from Polecat Aeroplane Works is a 4-channel competition discus-launched glider (DLG). I bought the SideWinder because I wanted to have a competition-class DLG to fly in the 2008 Polecat Challenge in mid-June 2008.


I ordered the SideWinder II on 2008-01-25, received it on 2008-02-24, and started construction on 2008-03-15. Construction was finished 2008-05-20, and the maiden flight was 2008-05-23.

Equipment used:

All-up weight (AUW) is 10.2 oz, giving a wing loading of 4.3 oz/sqft.

This SideWinder was built stock, and flown that way in the 2008 Polecat Challenge. Since that time, I've replaced the throwing peg with an offset carbon throwing blade. I've also replaced the very fragile plywood aileron control horns with carbon horns.

Build log

Total build time was 25.5 hours over two months. (Yes, I'm a slow worker—the whole build should have taken around 10 hours.) Here's a mind-numbingly boring play-by-play build log:

2008-03-15: Rout out servo bays to match D47 servos. Prepare hardpoint cavities in wing roots. Join wing halves together with epoxy filled with microballoons and carbon fiber. (3 hours)

2008-03-19: Add glass reinforcing to wing joint. (1 hour)

2008-04-06: Drill out forward bulkhead for 1/8" carbon wing pins. Match drill wing leading edge for pins, epoxy pins in place. Drill & tap holddown plate for wing bolt. (3 hours)

2008-04-08: Sand boom. Measure for stab mount. Measure again. Fabricate drilling fixture, drill matching holes in stab. Cut out 1/32" plywood doubler, drill matching holes. (1 hour)

2008-04-12: Sand leading edge of fin to shape, harden with CA. Measure boom for slot for fin mount. Grind slot in boom, fit and glue fin. Reinforce with Kevlar thread. (2 hours)

2008-04-13: Sand leading edge of stab to shape, harden with CA. Slot elevator for control horn. Glue in place. (1 hour)

2008-04-30: Bore holes in forward bulkhead for wing servo wiring harness and secondary receiver wiring. (0.5 hour)

2008-05-11: Slot rudder for control horn; glue horn in place. Glue pushrod housings to boom, trim housings to length. Reinforce fin/boom joint with fiberglass & epoxy (both sides). Attach 0.025" wire ends to rudder pushrod with CA and Kevlar thread. Mount rudder servo with Goop. (3 hours)

2008-05-12: Attach 0.025" wire ends to elevator pushrod with CA and Kevlar thread. Mount elevator servo with Goop. Attach ramp for rudder pushrod housing. (1.5 hours)

2008-05-16: Fabricate aileron servo wiring harness, with wires through bulkhead and plug for removing wing. Connect all servos, bind radio, and test. (2.5 hours)

2008-05-17: Shorten and re-solder aileron wiring harness. (1.5 hours)

2008-05-18: Slot ailerons for control horns; glue horns in place. Fabricate carbon-fiber and wire aileron pushrods. Glue aileron servos in place. Sheath main and satellite receiver antennas with heatshrink to protect against chafing. Bore holes in fuselage for satellite receiver antennas. Bore hole in wingtip for throwing peg; epoxy throwing peg in place. (3.5 hours)

2008-05-19: Fit main receiver into fuselage. Program preliminary radio setup. (1 hour)

2008-05-20: Shape wing seat to fit wing by filling gap with mixture of epoxy and microballoons. Solder connectors on BEC-alarm combo gadget. (1 hour)

Some construction images:

Wing servo cutout Wing servo bay Wing root -- ready to join Wing joint Wing joint Wing mounting pins Wing mounting pins Stab mount Stab mount Slot for fin Fin mounted Elevator horn Tail group Rudder pushrod & L-bend Rudder servo in place Elevator servo in place Rudder & elevator servos installed Ramp for rudder pushrod housing Aileron servo wiring Wing plug Rat's nest Aileron control horn Aileron servo mounted Aileron servo mounted Heatshrink to protect antennas Choosing a throwing peg location Throwing peg mounted