On Saturday, February 6, 2021 at 7:05:37 PM UTC-7, 2G wrote:
On Saturday, February 6, 2021 at 5:18:16 PM UTC-8, kinsell wrote:
On 2/6/21 8:05 AM, Mark Mocho wrote:
Sorry, but I disagree that electrics will turn "pure" sailplanes into a fringe activity. I personally like pure sailplanes over motorgliders and sustainers. Probably comes from 28 years of hang gliding and 20 years of gliding (45 years total). I played around with powered ultralights, but never really wanted one. I have a self launch endorsement in gliders (as well as two turbojet Type Ratings in jet powered two-seat gliders), but I prefer unpowered flight for the challenge, as well as lower complexity and lower insurance costs. Sure, I am forced to depend on tows, but you can pay for a LOT of tows with the differential in the price of a motorglider. As far as propulsion type, I don't particularly care for the limited battery capacity due to poor energy density compared to fuel. And don't kid yourself that batteries are completely safe. Any energy storage system has risks of 'dumping' that energy in an enthusiastic manner. Everybody screeching about getting rid of oil & gas had better do some research on what it takes to produce a wind turbine. (Hint: They don't grow from magic beans.) And you might not have noticed, but there are NO solar-powered solar cell factories. And the Tesla S 100 kWh battery (1,375 lbs.) stores the energy equivalent of 2.1 gallons of AvGas.

Perfect solution would be a battery-powered winch. Hook a bunch of
batteries up to a motor, hook the motor up to a drum. How hard could
that be? No folding props to deal with, no certification, no annual
inspections, no insurance, no skilled labor required to run it. Plus
you don't have to carry a load of undumpable ballast around with you all
the time.
I ran into a guy (who's name I can't remember) at the 2016 Reno Convention who's club was in the process of designing an electric winch using direct DC drive. It is a non-trivial task.

Tom
https://www.hdelectriclaunch.com/