Arn't you a bucket of cold water , after deciphering your form of spelling. You have to think outside of convention to advance. Do you have calculations to back up your assertions or are you just speculating?


Just Saying,


One Sky Dog
120 miles, 10,000 ft altitude gain, Magic IV June 1989

Sent from my iPad

On Dec 19, 2012, at 11:45 PM, russell wilson <This email address is being protected from spambots. You need JavaScript enabled to view it.> wrote:


regenerative braking to generate electrical power on a sailplane is pointless......once a prop starts windmilling it becomes an air brake not the size of the prop but the entire disk area...you will generate moor drag much moor than you will get back in lift/electrizerty.

the idea of turning the prop over to match air flow so the prop gives no drag .....how will you manage this when you have diferent air speeds all the time?are you going to have a speed controller controlled by software reciving airspeed information from an airspeed sensor,or will you have a triger and operate it manually whilst you watch your airspeed indicator?whilst you fly the glider and stratigise your next thermal sorce and flyte path..and will the battery life match the flyte duration? your going to do none of them its an idea from a primary school student...let the prop stop or use a fethering prop or a folding prop or turn the motor and prop 90 deg to port or stabord thus fethering a non folding prop or better still dont use any propolsion.

you may be able to use a windmilling prop for glide path controll and discard the air brakes.after you run the idea by an aerodynamist.but i think you might find he will tell you that this will upset the airflow over the tail...the high centre of drag will pitch you up/stall you...your on landing approach so you are low...the aircraft will pitch nose down into the ground and your motor mount will brake at the base of the pole mount and hit you like a 20 kg sledge hammer with ninga swords spinning.

russell wilson.


On Thu, Dec 20, 2012 at 10:29 AM, Michael McKeown <This email address is being protected from spambots. You need JavaScript enabled to view it.> wrote:


On one of the lists recently, or maybe it was a product I read about, anyway the point that stuck with me is the concept of turning the motor over slowly in flight so that the prop is moving through the air without drag. That allows one to use regenerative 'braking' in a way a folding prop would not allow.

M.




On Dec 19, 2012, at 2:58 PM, russell wilson wrote:





hi i forgot yesterday to mention in relation to electric power.....royobi and other manufacturers are making mowers and chain saws 36 v now and are using lithium ion batteries and chargers to suit...i dont think they have power controllers though.(the gnome engine on the focka try plane...red barron....had no speed controller/throttle....it was contrilled when taxing by an on off switch:)
i dont know much about this side of things.
props are generally 80% eficient.
weight devided by glide ratio is a rough calculation for thrust required for level flight.
a large slow diameter prop seems better for low power.
folding prop joints get hammered by single cylender motors.
thats about all i got on this subject.
russ.