Not very familiar with electric flight. what is the purpose of the brake on some esc's for. Do I need to activate it for my Goldberg Gentle Lady.

I think it is used to either allow the prop to spin or not spin when at no throttle. I could be wrong though. I'm setting up my first real electric and this is one of the settings. I haven't gotten to setting up the ESC yet.

It's really used more for cars.

If you're using the folding style prop, then yes, use the brake. It will stop the prop and allow it to fold back and reduce drag for your glider.

I am using the folding prop. thanks

VERY FUNNY ( could be true though cuz I know zilch about cars)

With gliders a brake will stop the rotation of the prop when power is off allowing a FOLDING prop to fold. Soft brake option is less stressful on the prop roots as is soft start.
If you are using a NONFOLDING prop let it spin for less drag. (won't be a big difference though)

A free spinning propeller has a lot more drag then a stopped propeller. If you want to use the propeller as an air brake then turn the ESC brake off. If you want to be able to extend the glide turn the ESC brake on. You can also set it up so your trim will turn it on and off, so you can effectively have an air brake.

Due to my complete lack of knowledge of electric I went to the Watt Flyer web site and got all my information and help there. After i have built and flown my first one I discovered I had forgotten everything I learned and I'm back there reading up for my second electric plane. Very fun people and a lot of information.

Many of the flyers at our club use Minimal braking. On landing your aircraft, braking will stop or slow down the prop "free spin" to allow a more precise landing. Also; Stopping the prop at the top of a vertical climb might be usefull for hammerhead stalls and similar manuevers.
Quite a few guys insist on braking when using 3-4 blade props.

If stopping the prop is a requisite for a precise landing I'm going to have to revisit the setup on all my gassers

As for hammerheads, blowing some air over the rudder is a good thing.

one more reason to add, why i dont have any electric models

Prop brakes are also used in aerial photography to minimize any vibrations of the motor.

Nah..it's to stop your takeoff from getting to long quiet and boring

It is to stop the plane from crashing. Doesn't anyone here watch Bugs Bunny????

Minnflyer was being serious. Usually the only r/c that uses brakes on an esc is cars.

And folding props for gliders

The brake is VERY important with cars.

Minnflyer is a GREAT recourse. Extremely helpful, knowledgable and an all around nice guy.
None of the above are good reasons to stop giving him an occasional hard time though

I send all my new guys to his stickies.

2 reasons why a free wheeling prop hurts the glide that come to mind....

a spinning prop looks like a solid disk to on-coming air, it's colliding with more air in less time than if it was stationary.

some of the stored energy [model weight, height and gravity] that is being used to glide is being used instead to turn the prop.

Oh Man!! OzMo, you know how hard it is going to be to live with Minnflyer now. [][][]

With belly-landed planes (i.e. planes with a prop swing that will strike the ground when landing) you want to stop the prop before you land. With nitros, you just kill the engine and the compression stops the prop (and you try to "time" the prop so that it stops horizontal with the compression). With electrics, unless you have the brake set up, it will still spin after you kill the throttle (from momentum and windmilling). The brake slows the prop down quickly so you are less likely to break your prop when you belly-land the plane.

Goirish,

I have to agree with CombatPig's post :Stopping the propeller, even if it's not a folding one, reduces drag dramatically (for the reasons CP brought up).

I've built a Goldberg Gentle Lady that was sold with a 400 electric motor in the early nineties. It was called the Electra at the time if I remember well. As I didn't own an ESC at the time, it was rigged with a servo-controled common switch (on-off). Gliding with the engine off and the propeller free-spinning felt more like flying a Buick_Electra than a Gentle Lady. Launching by hand with the propeller secured (no-spin) greatly enhanced flight times.

That is entirely too much information.