blue77

My Feedback: (178)

Please pardon my ignorance but....I just got my first electric and I'm wondering if its possible, or any reason to install an exterior switch to power up the system. I would really feel better safety wise if after charged batteries are hookedup and canopy is install if I could flip a switch to power the system...any info or ideas? Thanks, WC

BarracudaHockey

My Feedback: (11)

Current draw on electric motors is the reason, most switches that could handle 35 amps would weigh as much as your plane.

You can make a jumper from deans connectors but really, if you have a good radio the best thing is to program up a mix to act as a throttle hold,

Dsegal

You can have an arming switch on a brushed motor. But the ESCs for brushless motors have a large capacitor which will fry any reasonably sized switch when the switch is closed.

joeshmoe_44883

My Feedback: (2)

i just completed my first normal sized (.40 nitro sized) plane. I couldn't use the ESC's BEC, so i powered up the servos and receiver with a separate battery which meant i had to use regular rx switch to turn it on an off, just like on a nitro powered model. so when i plug in my two 3 cell lipo's, the motor cant power on until i turn on the receiver.

exeter_acres

My Feedback: (2)

Be VERY careful with this setup......

when you plug in the LiPo battery.. even though there is no power to the RX or servos... the motor is LIVE!
anything can happen.

BarracudaHockey

My Feedback: (11)

I agree, Transmitter, receiver, THEN arm the motor.

joeshmoe_44883

My Feedback: (2)

i agree but the plane is a electric conversion, there no way to make a hatch an keep the batteries where they need to be to keep the cg. its a biplane and i have to take the wing off every time to charge and change batteries. that means i have to unhook the aileron links, take out the wing braces, flip it over and then take off the wing, just for 2 batteries. i agree theres power to the motor, and i think twice before i grab an flip it around, but with out the reciever getting any power, the esc cant engage the motor without gettin a throttle input. thats like saying a idling nitro model will hit full throttle and take off with out its reciever turned on. if i had another option i would have gone with it, but there isnt, plus its nice knowing that even my lipo's go dead or something happens with that system, i'll still have control.

FlyStraight

On an esc like the one from castle creations, it has auto motor cutoff so if the rx looses signal the motor will shut down. On those esc's it's safe to plug in your lipo with you tx off. You might be also able to program your rx failsafe to shut the motor off.

But, here is the thing. If you get an esc that doesn't do that or your failsafe is not set then with other esc's you might get into trouble. It's better imo to learn the safe system ie. tx on first then rx so that you can use any other esc and not get into trouble.

chuckk2

I just bought an E-Flite 60A escape that has a low power on/off sw built in. If you have to have a full power disconnect, just about any of the Deans or other power connectors can be used.

It's possible to use some automotive switches, IF the switch is only closed or opened when the current draw is minimum. "Carry current" ability is normally much higher than make or break current.

Closing a contact at higher than rated can weld the contacts. Opening contacts at higher than rated can damage the contacts and with continued use cause the contacts to overheat and fail, or stick closed. Obviously, if such a switch is used in desperation to open under load, replacement is a good idea.

Long ago, I used to work in engineering for a company that built (among others) switching devices for well over a century. A small contact might require a microscope to see, and a large one a fork lift to pick up.

4*60

My Feedback: (41)

That word "can't" in the middle there might cost you a finger or two. It is not correct. There is power to the esc and to the motor and the esc is a computer device. Good luck!