Wind sim, to use a motor shield or not?

[SafetyThird]

I’m looking at building a wind sim as my first sim hub project. I see that some people use a motorshield and some just wire the PWM fan sensor direct to the arduino and run power independently to the fans. Is there any benefit to one over the other? The direct route seems to remove the cost of the motor shield and any issues with powering higher power fans.
thanks.

 

[Deleted member 1066209]

I've got a wind sim powered by SimHub and I'm using a motorshield. The fans emit a high-pitched sound when operating anywhere below full speed. The SimHub documentation makes note of this.

The sound is kind of annoying. Since I'm using the HP Reverb G2's speakers, I can hear it when the audio is turned down. If you've got a closed-ear headphone set, you're unlikely to hear it.

I made plans to construct another wind sim using PWM fans, about 6 months ago, but haven't gotten around to it; so it's not terribly annoying, either.

Also, my motorshield has 4 outputs for motors/fans, but it can only power 2 Noctua fans effectively. I think PWM fans are ideal because (I'm guessing!) you can send the PWM signal to as many fans as you'd like, since they're drawing from an independent power supply. I haven't confirmed whether this will work, though, so I may be wrong about this. The SimHub documentation states that the Arduino supports up to 3 PWM fans, but I'm interpreting it as 3 different PWM signals.

 

[metalnwood]

I've got a wind sim powered by SimHub and I'm using a motorshield. The fans emit a high-pitched sound when operating anywhere below full speed. The SimHub documentation makes note of this.

The sound is kind of annoying. Since I'm using the HP Reverb G2's speakers, I can hear it when the audio is turned down. If you've got a closed-ear headphone set, you're unlikely to hear it.

I made plans to construct another wind sim using PWM fans, about 6 months ago, but haven't gotten around to it; so it's not terribly annoying, either.

Also, my motorshield has 4 outputs for motors/fans, but it can only power 2 Noctua fans effectively. I think PWM fans are ideal because (I'm guessing!) you can send the PWM signal to as many fans as you'd like, since they're drawing from an independent power supply. I haven't confirmed whether this will work, though, so I may be wrong about this. The SimHub documentation states that the Arduino supports up to 3 PWM fans, but I'm interpreting it as 3 different PWM signals.

If you add inductors to the wiring you can all but eliminate that noise. I had it as well, then added the inductors and only a faint whine just as they are about to start up.

 

[SafetyThird]

Thanks very much, that’s very helpful. Like you, I’m using a reverb G2 so while noise isn’t my biggest issue, it’s definitely there. I think I’ll go with PWM fans and leave out the motor shield.
Time to shop for parts and fire up the 3d printer

 

[Brett Boots]

If you add inductors to the wiring you can all but eliminate that noise. I had it as well, then added the inductors and only a faint whine just as they are about to start up.

Thanks for the response. Do you have an image or name of the type of inductor you used and what power it was rated for? Did you simply just solder both ends in the middle of the wire? Did you then wrap it in electrical tape?

For reference /anyone else googling: I have a wind sim with an Uno r3, cytron mbb10 and 2 x 1.5a DC fans and am also getting the whining sound. I am unable to adjust the frequency I simhub because the option I used is "SHAKEIT PWM Outputs" doesn't allow for this.