(already sent to Evan personally) If a current Cobra (Alko) axle
available from Williams Soaring won't fit, use Axle, Inc, Elkhart,
Indiana.
They manufacture Alko Kober axles to your spec. The suggestion
included buying the mechanical brake parts from Williams, and having
Axle build a mechanical brake axle with them. Electric ties you to a
small percentage of vehicles. Hydraulic actuators are not so bad, but
what do you do with either for a parking brake and moving around
without the car?
Modern glider trailers already have the mechanical linkage with
parking brake mechanism on board. Best to stick with it
Jim

http://www.williamssoaring.com/

http://www.axleinc.com/