Question about the bms 22hv blue bird

[mcstan]

Hiya

I was working on my baby tricopter and was in the tuning part, I was finding my servo was getting warm.. but was not sure why.. it was set to v8 on the bec went in to tail tune mode and started working on doing the left tilt motor went fine over and stopped moving.. after looking very confused, I powered off the tricopter and found the motor had complete locked solid, now I read on here and bluebrid site that this servo would be able to take 8v but hobbyking say 7.4v … did i buy the wrong one and over did it?

I did try to check the power on the cable.. sadly rushing i had sorted the feed when checking it on the meter.

so far I’m down a servo and pdp… dang it..

[mcstan]

okay I order my self this time the BMS-21HV seen the other out of stock and the specs seem the same part from it can lift more but slower then the 22HV

I guess what i really want know.. before killing a new servo was I unlucky with running the other one at V8 on the baby PDB? because killing 20 pound servo kind sucks lol 😛

[Deepnine]

I killed both of my 22HV with 8V. It’s rated up to 8.5V. I belive its to weak. The first one worked for a week, the second one died on the bench.

210DMH 3.9kg/cm (stock)
vs
22HV 2.5kg/cm

21HV 3.2 kg/cm
20HV 4.3 kg/cm

The next one i try is the 20HV. Bit more torque than stock. It should be also faster with load.

[mcstan]

ahhhh okay… least its just not me then

I got the 21HV one seen its the only one I found in-stock I order my self a Pololu 7.5v 2.5a which should be able to handle it

how do people work out how much torgue someone needs for a tail anyways?

did you managed to test the feedback wire bit to see if it does 0 to 3.3v because i need to check that also.

[Terje]

I’ve flown my HV22 on 8v no problem (Until I crashed it and broke the gears). Connecting the servo feedback wire to the GPIO pin on a SPRF3 board will fry the servo motor though…

[mcstan]

Hi Whats the GPIO pin???

I had my one connect to the FB on the F3FC but failed to test if the servo was outputting 3.3v

[GAntonjo]

@dkdarkness: I have my RCExplorer servo with feedback wire connected to my SPRF3 Clone RSSI pin, though only operating the servo on 5V. Is it the 8V that will fry the motor when connected as you suggested?

[Terje]

@GAntonjo servo works fine on a SPRF3 on 8V if connected correctly. Sadly the RSSI/CURRENT pins can be confused with the GPIO/PPM pads on the other side of the board. Servo will swing to one side and the motor burns out if servo feedback is connected to GPIO by mistake. (Basically messing with the potentiometer on the servo confusing it so it does not know where it is supposed to be).

[mcstan]

mmmmm I had the wire solder to the FB pad on the F3FC Racing board i double checked it.

i’m just waiting for my new PDB

[mcstan]

just to let you know

i’m working fine on the bms-21HV running on 7.5v with Feedback Wire

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