Wiesel Mega - Build and Flight

SpeedsterDEN "Wiesel Mega" build overview and flight at Hallet Cove, SA, Australia in 10-12 kts of wind. The goal was to build a light (rather than stiff and ballast-able) and transportable/storageable Wiesel Mega, so there is no spar, little tape and the fin is detachable.

The result is a slope soarer that turns quickly, loops like mad and flies slowly and gracefully. It struggles to fly inverted; probably due to the wing profile.

Hotwired from SL grade (13kg per m³) expanded polystyrene (EPS) from All Axis (http://www.allaxis.com.au/) using separate root and tip templates.

Root chord is 620mm plus 75mm aileron. Tip chord is 300mm plus 75mm aileron. Unlike the original Wiesel, these ailerons are not tapered. Note that the templates include the ailerons; just cutaway enough EPS after hotwiring the wings and replace with separate ailerons. Maximum thickness at the root is about 60mm. The front tip is set back 200mm from the root.

Wings are 900mm each with a 42mm thick fuselage yielding an overall wingspan of 1842mm. Overall length, including fin, is 1000mm. Fuselage is 820mm long. The nose extends 120mm in front of the wing.

Ailerons are 2.5mm balsa and attached to the wing with 3M Blenderm tape. Control horns are 3mm balsa attached with super thin CA. Pushrods are 2.0mm carbon fibre rod with garden wire attached with heat shrink tube and CA glue. The rods were slightly larger than 2.0mm, so the linkage stoppers were drilled out to 2.5mm.

Fin cut from 6mm SL grade EPS and taped with glass fibre tape around the edges and over the tabs pushed into the fuselage. Fin is 240mm tall and 330mm long.

Leading and trailing wing edge and wingtips covered with glass fibre tape. As was the nose and fuselage under the wings.

Standard servos and all electronics are located as far forward as I could to get the center of gravity (CG) correct at 180mm from the leading edge, which still required 280g of steel in the nose. All up flying weight was 1030g.

Full throws on aileron and elevator makes for good roll and excellent pitch authority. No expo (I'm not a fan, but most other people would use expo here).

Root template: https://www.rcgroups.com/forums/attac..., then enlarged to 200%.
Tip Template: https://www.rcgroups.com/forums/attac..., then enlarged to 200%.
Carbon fibre push rods: http://www.carbonfiber.com.au/prod17.htm
Glue: https://www.bunnings.com.au/sikabond-...
CA glue: https://hobbyking.com/en_us/hobbyking...
Glass fibre tape: https://hobbyking.com/en_us/high-stre...
Packing tape: https://www.bunnings.com.au/bear-48mm...
Blenderm tape: https://hobbyking.com/en_us/1-x-4m-ro...
Receiver: https://hobbyking.com/en_us/orangerx-...
BEC: https://hobbyking.com/en_us/micro-bec...
Servos: https://hobbyking.com/en_us/hxt-10kg-...
Linkage stoppers: https://hobbyking.com/en_us/brass-lin...
LiPo: https://www.modelflight.com.au/e-flit...

The Wiesel Mega first flew in 2012 (   • Mega maiden.  ). All Wiesels are covered in https://www.rcgroups.com/forums/showt... .


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