Servo's direct on 2S lipo - am I doing it wrong ?
04-23-2013, 12:55 PM
#16
I have seen some LiPo's have their wires colored in reverse to where the single Red wire coming from the balance port is true negative and the remaining black wires are looped positive in series, you should double check polarity with a voltmeter before assuming any color.
More info here:
http://scriptasylum.com/rc_speed/lipo.html
More info here:
http://scriptasylum.com/rc_speed/lipo.html
04-23-2013, 01:05 PM
#17
If you are going to hook the wire directly up to the ESC connector, then it's extremely important to always have a radio signal from the Tx going, otherwise you risk the servo going full tilt and burning the motor out if power is applied to the servo without any filtered signal.
I was very lucky once when my kids inadvertently left the battery plugged into my crawler, but turned off the ESC switch and then the Tx, not realizing power was still going to the steering servo. I didn't realize it until hours later and my Solar D772 was so hot I could barely touch it without burning my finger. After the servo cooled, it worked just fine later that day
I was very lucky once when my kids inadvertently left the battery plugged into my crawler, but turned off the ESC switch and then the Tx, not realizing power was still going to the steering servo. I didn't realize it until hours later and my Solar D772 was so hot I could barely touch it without burning my finger. After the servo cooled, it worked just fine later that day
04-23-2013, 01:22 PM
#18
If you are going to hook the wire directly up to the ESC connector, then it's extremely important to always have a radio signal from the Tx going, otherwise you risk the servo going full tilt and burning the motor out if power is applied to the servo without any filtered signal.
I was very lucky once when my kids inadvertently left the battery plugged into my crawler, but turned off the ESC switch and then the Tx, not realizing power was still going to the steering servo. I didn't realize it until hours later and my Solar D772 was so hot I could barely touch it without burning my finger. After the servo cooled, it worked just fine later that day
I was very lucky once when my kids inadvertently left the battery plugged into my crawler, but turned off the ESC switch and then the Tx, not realizing power was still going to the steering servo. I didn't realize it until hours later and my Solar D772 was so hot I could barely touch it without burning my finger. After the servo cooled, it worked just fine later that day
But if the RX is off, there's no signal on the yellow wire to the servo, so why would it "go full tilt" ?
And.. If not directly to the battery-to-esc-wires, how else would one connect the servo to the lipo ?
04-23-2013, 01:33 PM
#19
I am careful to turn on the Tx first, then turn on the ESC and finally hook up power to the servo last; then repeat steps in reverse order to minimize any risk damaging the servo.
Without any filtered signal, the servo arm can wildly tilt in one direction without any end point control... seen this happen with my Solar servos, don't know why this happens, but just my observation.
In theory, you could possibly tap the black wire to the servo in series with the same switch that controls the ESC such that the servo would then turn on at the same time the ESC is powered up thus providing a filtered signal from the Rx. I have not tested this theory yet, but I would think it's worth experimenting with trying out at your own risk.
Without any filtered signal, the servo arm can wildly tilt in one direction without any end point control... seen this happen with my Solar servos, don't know why this happens, but just my observation.
In theory, you could possibly tap the black wire to the servo in series with the same switch that controls the ESC such that the servo would then turn on at the same time the ESC is powered up thus providing a filtered signal from the Rx. I have not tested this theory yet, but I would think it's worth experimenting with trying out at your own risk.
04-23-2013, 02:55 PM
#20
I am careful to turn on the Tx first, then turn on the ESC and finally hook up power to the servo last; then repeat steps in reverse order to minimize any risk damaging the servo.
Without any filtered signal, the servo arm can wildly tilt in one direction without any end point control... seen this happen with my Solar servos, don't know why this happens, but just my observation.
In theory, you could possibly tap the black wire to the servo in series with the same switch that controls the ESC such that the servo would then turn on at the same time the ESC is powered up thus providing a filtered signal from the Rx. I have not tested this theory yet, but I would think it's worth experimenting with trying out at your own risk.
Without any filtered signal, the servo arm can wildly tilt in one direction without any end point control... seen this happen with my Solar servos, don't know why this happens, but just my observation.
In theory, you could possibly tap the black wire to the servo in series with the same switch that controls the ESC such that the servo would then turn on at the same time the ESC is powered up thus providing a filtered signal from the Rx. I have not tested this theory yet, but I would think it's worth experimenting with trying out at your own risk.
Same goes for powering up without a signal, good thing to check. Hasn't been a problem for me, but can't assume that for all setups.
Last edited by Dave H; 04-23-2013 at 03:07 PM.
04-23-2013, 04:16 PM
#21
The wiring-scheme I'm getting from most people would make this very hard, since the servo would be connected to / powered by the lipo as soon as I plug the cables in, while the TX would only get its power once these cables are plugged in AND the Esc-switch is turned on...
04-23-2013, 08:03 PM
#23
I have your answer. This has worked on a couple of hobbywing/speedpassion esc's so far and should work on most any esc. Plug in a battery and check for voltage on each side of the switch. One side of the switch should have the same voltage as the battery. Now disconnect the red wire from the esc going to the rx and connect it to the switched side of the switch. Just remember if you run a 3s pack that the servo and rx will be getting the same voltage as your battery. You now have the same factory switch controlling everything as it should. I actually pulled my esc apart and changed the wires at the board. It takes me about 5 minutes to do it now.
The servo goes to wherever you set the failsafe to when you turn the tx off and leave the rx on. I burned an expensive servo up this way years ago.
The servo goes to wherever you set the failsafe to when you turn the tx off and leave the rx on. I burned an expensive servo up this way years ago.
04-24-2013, 04:38 AM
#24
Except he mentioned earlier he doesn't have a high voltage receiver. Need to keep the receiver on the speedos BEC power.
04-24-2013, 04:45 AM
#25
What kind of rx is it?
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