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Old Aug 10, 2008, 05:24 PM
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Madison, WI
Joined Feb 2004
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Arming Switch?

I'm a relative newbie to electrics. When I'm at the field, why don't I see an arming switch on just about everyone's electric plane? Everyone turns on their transmitter, gets the right model (memory) punched up, makes sure the throttle stick is all the way down to no power and then plugs in the battery. It would seem to me that an arming switch would add an extra bit of safety in terms of plugging in the battery and turning on the transmitter. All of my glow planes have an on off switch. At a recent electric only fun fly one of our club members was getting ready to fly, something went wrong, and the motor suddendly started up and he got cut badly. I believe an arming switch would have prevented that. What am I not understanding here?
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Old Aug 10, 2008, 06:11 PM
turn, turn, turn.
Athol, Massachusetts
Joined Oct 2005
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A charge jack/switch for a rx. battery is fine.

When using the bec in the esc for powering the rx. and servos, no cherge jack/switch is necessary.
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Old Aug 10, 2008, 06:22 PM
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Staffs, UK
Joined Nov 2003
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Unless the switch is a large heavy one which completely disconnects the battery it will not prevent all possible cases of "something going wrong" and motors coming on unexpectedly. And adding a switch like that would be adding another failure point where something could go wrong.

So we all just treat a plane with the battery connected as armed (and dangerous)....and very few of us have any problems.

BTW you say your glow planes have an on-off switch....but on just about every glow plane I've owned or seen it's still possible to start the engine with it switched off. So it's not exactly much of a safety measure .

Steve
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Old Aug 10, 2008, 07:55 PM
jrb
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Edina, MN, USA
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I do!
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Old Aug 10, 2008, 09:17 PM
Registered User
Madison, WI
Joined Feb 2004
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Arming Switch

Thank you guys! I've got it now. As an extra measure of protection I plan on wrapping a rubber band or light bungee around the throttle stick, in it's off position, around the back of the radio hooked around the antenna or something else so as to keep pressure on the throttle when in the off position.
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Old Aug 10, 2008, 11:08 PM
War Eagle!
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Birmingham, Alabama
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Some of the higher-end ESCs actually come with an arming switch/on-off switch. I have one of those now, and I really like it. Nifty, indeed! Though sometimes I wonder why my plane is not doing a thing even when everything's plugged up!

I've seen people do the PowerPoles thing, and it definitely is cool. I'd love to use it for a bigger project. Very nice!
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Old Aug 10, 2008, 11:17 PM
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Swanton, Ohio
Joined Feb 2005
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Quote:
Originally Posted by Spackles94
Some of the higher-end ESCs actually come with an arming switch/on-off switch. I have one of those now, and I really like it. Nifty, indeed! Though sometimes I wonder why my plane is not doing a thing even when everything's plugged up!
Some will say that the on/off switch is not really disarming the system. If the switch fails (I've never had one yet) there is that chance that the motor could still come to life as the packs are still connected to the esc.

By using a shunt (arming switch) you are disconnecting power to the battery packs by breaking the circuit.

Tim
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Old Aug 10, 2008, 11:20 PM
War Eagle!
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Birmingham, Alabama
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Quote:
Originally Posted by sun.flyer
Some will say that the on/off switch is not really disarming the system. If the switch fails (I've never had one yet) there is that chance that the motor could still come to life as the packs are still connected to the esc.

By using a shunt you are disconnecting power to the battery packs by breaking the circuit.

Tim
Touché!

Another thing to keep in mind, too... Most mid-range to high-end ESCs (at least all the ones I've used) usually have a built-in safety feature that won't allow them to arm the motor until the stick is all the way down.

A Jeti 12 ESC that I have goes the extra mile, and won't arm until it's down and then you go over half throttle.

That does give me a tad more peace of mind as well.
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Old Aug 10, 2008, 11:23 PM
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Quote:
Originally Posted by Spackles94
Touché!

Another thing to keep in mind, too... Most mid-range to high-end ESCs (at least all the ones I've used) usually have a built-in safety feature that won't allow them to arm the motor until the stick is all the way down.

A Jeti 12 ESC that I have goes the extra mile, and won't arm until it's down and then you go over half throttle.

That does give me a tad more peace of mind as well.

The Silver Series line of speed controllers from Great Planes won't let you arm until you go full throttle (one beep) then close throttle (two beeps).......then its armed.

Only problem is what happens if for some reason your rx looses signal to the tx (range check scenerio) what will happen to your throttle???

Tim
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Old Aug 10, 2008, 11:26 PM
War Eagle!
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Birmingham, Alabama
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Quote:
Originally Posted by sun.flyer
The Silver Series line of speed controllers from Great Planes won't let you arm until you go full throttle (one beep) then close throttle (two beeps).......then its armed.

Tim
Very nice, indeed!

Of course, if you keep going full throttle/no throttle/full throttle/... for a few more times, you may end up in programming mode, and it could all go downhill from there really quick...
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Old Aug 10, 2008, 11:51 PM
Balsa to the Wall
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I use the throttle lock on my TX until it's ready to take off.



Chuck
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Old Aug 11, 2008, 12:41 AM
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Indiana
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As you've seen in the pictures if you have a large model and don't mind hauling around dead weight then a separate arming setup is doable. Smaller, lighter models usually require nothing more than plugging in the battery when you're ready to fly. Some planes just don't have the internal room for a arming setup. Turning off the power to the rx itself while leaving the motor power applied is generally considered unsafe.
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Old Aug 11, 2008, 08:27 AM
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Kingston, Canada
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Couple of yrs ago a fellow had a Zagi sitting on the bench with the prop hanging over the edge. Batt. was plugged in with the ESC switched off. Sitting around BSing and the motor went up to about half throttle by itself. Had to unplug the batt. to get it to stop. Just a stray signal can trigger it. With the Spektrum, with the batt. plugged in and no ESC switch, and the trans. turned off, the motor will not start, as the rcvr. is programmed to throttle off when the trans. is turned off.
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Old Aug 11, 2008, 09:57 AM
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Indiana
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R.E. Spektrum. How can any programming in the rcvr take control of the situation when there's no power to the rcvr? I would think the randoms motor starts we hear about are caused by noise in the signal line to the esc, not from the unpowered receiver.
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Old Aug 11, 2008, 10:05 AM
Canadian Bacon
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Kingston, Canada
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The rcvr. is turned on with the ESC and batt plugged in. Only the trans. is turned off. With any stray signal coming in, the rcvr will not let it turn on the motor as the failsafe throttle setting is Throttle Off.
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