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Futaba Receiver and High Voltage Servo Setup Question

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Will a 10 amp BEC work for two servos? I have two AGFRC 74KG high voltage servos but can't find the wattage or amperage rating for them
The A81FHM servo which I think you have, are spec'd at 7400ma @ 8.4volts.

Digital_HV_74KG_0_125Sec_Super_Torque_4_Poles_Brushless_Programmable_RC_Steering_Servo_A81FHM__1702461556546_6.jpg


The info is in the pictures on their website. Don't know why they didn't list in their descriptions

If I was installing and planning on running 2s LiPo in the truck I'd just wire the servos in a BEC bypass configuration. That way no there's no need for a separate BEC or any extra failure points.
 
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The A81FHM servo which I think you have, are spec'd at 7400ma @ 8.4volts.

Digital_HV_74KG_0_125Sec_Super_Torque_4_Poles_Brushless_Programmable_RC_Steering_Servo_A81FHM__1702461556546_6.jpg


The info is in the pictures on their website. Don't know why they didn't list in their descriptions

If I was installing and planning on running 2s LiPo in the truck I'd just wire the servos in a BEC bypass configuration. That way no there's no need for a separate BEC or any extra failure points.
Thank you so much for sharing this. Very helpful.

So I ended up getting a BEC to lower to voltage from the battery for my receiver and I got a BEC bypass to connect the servos directly to the battery. Will update on how this works by end of this coming weekend.
 
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This is one of those RC wrong info from Brand . The 7.4 is off it means a 2 cell lipo ... There are a few others that have been said by Brands....
A fully charged 2 cell lipo will not blow the receiver ..if your that worried then you .pull the pos(+0 and negative wires out futaba plug and add the lipo to those 2 wires then plug single signal wire into receiver.

That is what my friend had to do ,he is running 4's Lipo in his 5th scale with 4's
servo's ,he had to make his own wire harness an run only the signal wire to the rec.!
 
most times theres major differences in speed and torque id be concerned .
RustyUs is not talking about being concerned that the servo isn't hitting full specs, he's talking about that he's not concerned about the extra volt to his receiver from plugging in a 2S lipo.

Will a 10 amp BEC work for two servos? I have two AGFRC 74KG high voltage servos but can't find the wattage or amperage rating for them
Yes a 10A BEC should be plenty. Hopefully its variable voltage so you can set it at 8.4V and get the most out of those servos. :)
 
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Hello Everyone,

I have a Futaba R404SBS receiver and the voltage specification on it says 3.7v-7.4v. I'm going to be using "high voltage" 7.4v servos with a 7.4v battery but am not sure what I need to make this work. Is there some type of voltage regulator on the market that drops the voltage down below 7.4v for the receiver?

And if so, how do I make my receiver output 7.4-8.4v for the "high voltage" servos when it receives voltage below 7.4v? Do I need a special high voltage receiver or something else? I've never run high voltage servos so am not sure how to do this or how people run these high voltage setups. This is for my 1/8th scale Team Associated RC8B4.1 nitro buggy. Would appreciate anyones advice and input on how to accomplish this. I've seen people running the high voltage servos but not sure how to do this when the futaba receiver is rated at 3.4v-7.4v.

Thank you!

What else in your system uses the battery? Can they run at the same voltage?

Just to clarify, the receiver does not provide voltage. Either the battery or BEC (battery elimination circuit) provide the voltage to the receiver and servos. The receiver gets voltage and provide a signal to the servo. They are wired in parallel and use the same voltage source.

Also a 2S battery is 7.4V nominal. A fully charged 2S pack is 8.4V, so I would recommend using a BEC or use and 8.4V compatible servo. A BEC can provide a constant 7.4 until the battery goes below that level.
1723915196241.webp


If you go that route make sure that eveything using the BEC can handle the same input voltage.
 
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