Cut off switch help

[mckibben]

I have been building and flying foamys for about a year. I think it would be great to have a cut off switch to the lipo battery. So when i install the lipo i can switch the plane on. And then switch it off. instead of taking the wing off before i turn the TX off. I am thinking an inline switch to cut off one side of the lipo. The switches i use in my nitro rc have thin wires. What switch can i use. And whats a good way to set it up.
Thanks Tom

[dumo01]

Tom
it is a nice idea but the problem is that most switches will not handle the current load of putting them in the path of the battery to the ESC. One thing you might consider is an arming plug. It is referenced among other places in this thread:

http://www.wattflyer.com/forums/showthread.php?t=62311

see post # 20

[CHELLIE]

here you go Tom And Welcome to Wattflyers, I read your profile, Favorite pet : Wife Thats a good one, I Love a sence of Humor in a person, Take care and have fun, Chellie

http://www.rctoys.com/rc-toys-and-pa...RS-WIRING.html

[FlyWheel]

I like the idea of an arming switch. However could you put one between the ESC and the motor (you only have to disconnect one wire to disable a brushless, right)? In theory this would let you power up the ESC and the reciever, then check all the servos without having to worry about your plane going Veg-A Matic on you? Obviously you wouldn't get a beep, because the motor does that and it would be disconnected.

Would this work or am I just whistling the Confederate national anthem?

[stevecooper]

Originally Posted by FlyWheel

I like the idea of an arming switch. However could you put one between the ESC and the motor (you only have to disconnect one wire to disable a brushless, right)? In theory this would let you power up the ESC and the reciever, then check all the servos without having to worry about your plane going Veg-A Matic on you? Obviously you wouldn't get a beep, because the motor does that and it would be disconnected.

Would this work or am I just whistling the Confederate national anthem?

the outie would still "phase" and bump around and jerk some,,,
best to made a deans switch from a male and female deans connectors, to switch + lipo lead. I use this set-up on a few planes, bubsteve

[stevecooper]

way down South ,,
in Dixieland!!!!!!!!!!!!!!!!!!your bub,steve

[CHELLIE]

Originally Posted by stevecooper

the outie would still "phase" and bump around and jerk some,,,
best to made a deans switch from a male and female deans connectors, to switch + lipo lead. I use this set-up on a few planes, bubsteve

Great Idea Steve Take care and have fun, Chellie

[kyleservicetech]

Originally Posted by FlyWheel

I like the idea of an arming switch. However could you put one between the ESC and the motor (you only have to disconnect one wire to disable a brushless, right)? In theory this would let you power up the ESC and the reciever, then check all the servos without having to worry about your plane going Veg-A Matic on you? Obviously you wouldn't get a beep, because the motor does that and it would be disconnected.

Would this work or am I just whistling the Confederate national anthem?

I'd be a little careful on just disconnecting one wire of a brushless motor to disable power to the motor. Could be some of those many many ESC's on the market won't like it. And maybe fail in the process.

[kyleservicetech]

Originally Posted by mckibben

I have been building and flying foamys for about a year. I think it would be great to have a cut off switch to the lipo battery. So when i install the lipo i can switch the plane on. And then switch it off. instead of taking the wing off before i turn the TX off. I am thinking an inline switch to cut off one side of the lipo. The switches i use in my nitro rc have thin wires. What switch can i use. And whats a good way to set it up.
Thanks Tom

You can find switches that can handle the current pulled by the ESC of a foamy model airplane. Problem is, that switch might be a fair percentage of the total weight of the foamy model airplane.

Most toggle switches don't go much over 10 Amps or so.

[Rockin Robbins]

Originally Posted by CHELLIE

here you go Tom And Welcome to Wattflyers, I read your profile, Favorite pet : Wife Thats a good one, I Love a sence of Humor in a person, Take care and have fun, Chellie

http://www.rctoys.com/rc-toys-and-pa...RS-WIRING.html

Wow, not rated for amperage. I'd have to get rid of those icky Deans Plugs too! EC3 FTW! Looks like trial and terror time though, with no amp rating.....

[stevecooper]

Originally Posted by Rockin Robbins

Wow, not rated for amperage. I'd have to get rid of those icky Deans Plugs too! EC3 FTW! Looks like trial and terror time though, with no amp rating.....

I make my own putting the female right on the hot leg and wire and solder the back of the male,, cover with heatshrink or tape,,Only one pair needed not three and no added wire either,,MUCH LIGHTER!! this will handle my power 10 pulling a butt-load of Amps with no probs or heat,,bubsteve

[JetPlaneFlyer]

Then there are some ESC's available that have an on/off 'arming switch'... such as the Air Boss ESCs by Extreme Flight.

I have one of these fitted to my Yak 54. While the switch does not physically disconnect the battery it does isolate the RC gear and turn off the ESC so the motor cant start.

I cant understand why these switches aren't used more commonly, seems like such an obvious good idea

Steve

[stevecooper]

Thanks,, your right,, it ain't right that they don't do that,,most my old brushed ESC did and do, bubsteve

[Rockin Robbins]

Originally Posted by stevecooper

I make my own putting the female right on the hot leg and wire and solder the back of the male,, cover with heatshrink or tape,,Only one pair needed not three and no added wire either,,MUCH LIGHTER!! this will handle my power 10 pulling a butt-load of Amps with no probs or heat,,bubsteve

A brilliant idea! Just like a bind plug on steroids and you KNOW it will handle the amperage you'll be using.

[slipstick]

Originally Posted by JetPlaneFlyer

While the switch does not physically disconnect the battery it does isolate the RC gear and turn off the ESC so the motor cant start.

I cant understand why these switches aren't used more commonly, seems like such an obvious good idea

They're probably not used precisely because they don't isolate the battery so it's still taking current. So unless you unplug the lipo it will still die.

Also they do not necessarily prevent the motor from starting up. An old clubmate of mine still has the scars to prove this after his motor kicked into life despite the ESC switch being off. An ESC usually won't arm with the switch off but if at the end of a flight you just switch off when the ESC is already live....it's still armed.

If I get an ESC with one fitted I remove it immediately...I don't like that false sense of security.

Steve

[CHELLIE]

Originally Posted by Rockin Robbins

Wow, not rated for amperage. I'd have to get rid of those icky Deans Plugs too! EC3 FTW! Looks like trial and terror time though, with no amp rating.....

Hi RR that disconnect has a 14 gauge wire on it, if your lipos have a 14 gauge wire on them or smaller, you can use it, most lipos have 14 gauge wire on them. Hope that helps, Chellie

[kyleservicetech]

Originally Posted by slipstick

They're probably not used precisely because they don't isolate the battery so it's still taking current. So unless you unplug the lipo it will still die.

Yup, the brushless ESC's are orders of magnitude more complex than the old brush type ESC. The brush type ESC basically had one Fet (or a number of Fet's in parallel). If you turned off the driver circuitry, that Fet just sat there, turned off, taking the load off of the battery supplying it.

But these brushless ESC's have a three phase driver with six Fets (or again parallel connected Fets). Turning off the driver AND the 6 Fets, with a little switch, is a problem not easily solved.

[John_]

Here is a winner! See these "ArmSafe" arming plug switch systems from www.sharpRC.com . Super small, even on the inside of the plane, and the actual plug is not all gangley like others. I use these on all my electric planes over 15amps. The pylon racing guys are running these at 80+ amps with 10AWG wire!! But when you get to these levels you need to be able to solder good, they have a video on sharpRC for how to solder deans plugs.