Fan slows down when on the throttle

[Lil Dylan]

I bought some radiocontrolpower fans for my Noto and I'm wondering if I have an issue. When I get on the throttle the fans actually slow down. Is this something normal or is there a voltage issue? I'm running an MMX 6s at BEC of 8.0v and the fans are 8.0v. There car isn't overheating or anything I'm just curious what's going on. Receiver is a Spektrum 6100. Any thoughts here?

https://www.radiocontrolpower.com/p...tor-bracket-with-40x28-fans-black-tron-covers

 

[morrjr71]

You may be experiencing brown out, where the ESC can't keep up with all the requirements for current placed on it. A servo that requires high current can be one factor in brownout, as can your fans.

 

[Jerold]

What do you mean by slows down. Is it a little or completely cuts out, only on full throttle or other conditions?

You can pull the data log and see if the BEC voltage drops at any point and look for other data points.

You may be experiencing brown out, where the ESC can't keep up with all the requirements for current placed on it. A servo that requires high current can be one factor in brownout, as can your fans.

Could be. The BEC is 8A and fans are about ~3A, which leave ~5A for the servo so it's possible.

 

[SrC]

You may be experiencing brown out, where the ESC can't keep up with all the requirements for current placed on it. A servo that requires high current can be one factor in brownout, as can your fans.

+!!!

What do you mean by slows down. Is it a little or completely cuts out, only on full throttle or other conditions?

You can pull the data log and see if the BEC voltage drops at any point and look for other data points.

Could be. The BEC is 8A and fans are about ~3A, which leave ~5A for the servo so it's possible.

+1
And some servos are amp hogs just sitting Idle. The servo could also be the issue.
Fans slowing down like this is odd and is not normal. And I bet this will influence the Servo negatively as well. All powered by the the BEC circuit.
Try dropping the BEC volts down a notch to see what happens.
Use a DVM to measure the output of your BEC voltage. See what you get.
You simply might be at the BEC's Amp limit already. A lower BEC setting might garner more Amps. IDK.
Amp ratings specs of ESC's BEC, fans and Servos are not truly accurate as well. Food for thought.

Edited.

 

[Garcbomber]

Try a glitch buster if that datalog shows brownout. What servo?

 

[Lil Dylan]

Well, I just tried to repeat the behavior on video and it didn't happen. The fans will slow down when I barely hit the throttle.

Servo is: https://www.amazon.com/FLASH-HOBBY-Brushless-Waterproof-Stainless/dp/B09N918KHB?th=1

I'll probably just lower the BEC and see if that eliminates the problem. It's frankly not a problem anyways I was just curious what was going on.

 

[Jerold]

Well, I just tried to repeat the behavior on video and it didn't happen. The fans will slow down when I barely hit the throttle.

Servo is: https://www.amazon.com/FLASH-HOBBY-Brushless-Waterproof-Stainless/dp/B09N918KHB?th=1

I'll probably just lower the BEC and see if that eliminates the problem. It's frankly not a problem anyways I was just curious what was going on.

Sounds silly but, make sure you don't have it connected to the power and the signal wire. Make sure it's on power/gnd.

I don't see an current spec on the servo, but it looks beastly, so I wouldn't rule it out.