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FAQ for Brushed Motor Quadcopters on Clean/Betaflight
#1
#1 - Basic Setup

Quote:set motor_pwm_rate=32000 #This will set pwm frequency to 32kHz
set max_throttle=2000          #brushed boards will use 0-2000 as throttle
set min_command=1000       #just to make sure min_cmd is not misconfigured
set fast_pwm_protocol=OFF  #disable oneshot125
feature motor_stop                #motors stopped when not armed
set min_throttle 1000            #the throttle when all motors start to spin, you might need to increase it if your motors spins when battery connected (e.g. 1060)


#2 - My motors spin full speed as soon as I plug in the Lipo battery...

Possible Causes:
1. Check your battery polarity (reversed polarity can cause this sometimes)
2. Motor PWM Rate too low => Read on

Solution: Go to CLI and enter

Quote:set motor_pwm_rate=32000  

And save. 


#3 - My Quad doesn't arm with stick...

Solution: 
1. Check your yaw/throttle stick range in Receiver tab, make sure both channels can at least reach 1000-2000. If not, adjust it in your TX settings (google how to do it with your TX Model)
2. If you prefer arming with stick, make sure you haven't setup a switch to arm (in Mode tab)
Don't be a LOS'er, be an FPV'er :) -- Blog - Facebook - Instagram - Twitter - Google Plus
[-] The following 3 users Like Oscar's post:
  • Helibus, Stan, KonradS
#2
Just as short remark to #3. The Eachine quads are shipped with arm binded to AUX5. If you do not reconfigure your TX and AUX5 is set to a potentiometer by default, it could be, that the quad is armed in the very moment you plug the battery in, because TX does not check the position of potentiometers.
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#3
Interesting, my QX95 came with the motor_pwm_rate set to 1000. Seems 'ok'. Should I change it to 32000 or just leave it alone?
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#4
(08-Nov-2016, 08:07 PM)JBFUK Wrote: Interesting, my QX95 came with the motor_pwm_rate set to 1000.  Seems 'ok'.  Should I change it to 32000 or just leave it alone?

in theory anything higher than 500 would work Smile
but i find higher rate gives me smoother flights. Experiment with yours, also pay attention to the motor temperature and time flight time, and use whatever gives you good result Smile
Don't be a LOS'er, be an FPV'er :) -- Blog - Facebook - Instagram - Twitter - Google Plus
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#5
Quote:Interesting, my QX95 came with the motor_pwm_rate set to 1000. Seems 'ok'. Should I change it to 32000 or just leave it alone?

If you increase the pwm_rate, you will get smooth and quite fly, but you will lose the thrust.  What I fund is that the rate between 8000 to 12000 gives the one I wanted. I'm using 0615 motors.
You need to try different numbers :-)
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#6
Like Dukevah said try different values for pwm_rate. I am using 8.5mm motors and I have mine set at 16000, it seems like a good compromise between smooth flight and thrust.
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#7
I have a Makerfire Micro FPV BNF . This is an inductrix / tinywhoop style 64mm quad with 6x15mm 17500KV motors. The instruction manual calls for setting the motor_pmw_rate @ 10,000. This seems to work well.
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#8
Hey everyone, I'm new to the forum and excited to be here! A quick question. I've modified the heck out of my inductrix and the latest mod, to get more flight time, was trimming my props to two blades. It increased flight time by 1 minute, which was great, but now it oscillates like a paint mixer. Will one of these fc's help me fix this issue? Someone mentioned on YouTube that it's the p factor causing the oscillation, especially since I have 17k motors, and that you can tune the board to compensate. Which boards are the most user friendly for tuning and do you think this will work? Thanks in advance!
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#9
Terry, I have the same Makerfire card - I can't connect to betaflight. Any suggestions? (Tried several m-USB cables, same results - no connection)

Product description says it's good-to-go out of the box, obviously I'm not seeing that. Should I flash card and start from scratch or am I overlooking something small and stupid?
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#10
Guys need your knowledge, I flash BF3.1.7 on my QX95 and QX90 and now the motors are getting ultra hot, this could be cause due to the MOTOR_PWM_RATE? mine is default 16000
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#11
(05-Apr-2017, 02:35 AM)Prr0 Wrote: Guys need your knowledge, I flash BF3.1.7 on my QX95 and QX90 and now the motors are getting ultra hot, this could be cause due to the MOTOR_PWM_RATE? mine is default 16000

I doubt it, but you could always try reducing the rate to 8000 or even lower. What were they running before? Did the motors get hot before you flashed 3.1.7?
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#12
(05-Apr-2017, 02:35 AM)Prr0 Wrote: Guys need your knowledge, I flash BF3.1.7 on my QX95 and QX90 and now the motors are getting ultra hot, this could be cause due to the MOTOR_PWM_RATE? mine is default 16000

Heat is going to be caused by low efficiency.  Different brushed motors have different "sweet spots" for efficiency.  Here's an old discussion on micro-motor wearhouse on the 0820-17 (I know that's not your motor and different FCs, but some interesting results there - ).

https://community.micro-motor-warehouse....cye/714/15

(There is even a bit on adjusting looptimes?)  I suggest trying several different PWM rates - even higher ones, to see if you can get things to cool down.
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