Exhaust fan noise - what's normal?

Baishy · Aug 23, 2017

Hi all,

Enjoyed my first flight with the H this evening. I love it, it's a beast. I'm enjoying not having to mess around with my phone and wondering if the DJI Go app is going to crash again, as it did with my phantom.

Reading the forums I'm aware there is a particular issue with fans in early St16s, which has been fixed. Mine is brand new, but I noticed as soon as I turned it on that the exhaust fan is quite a bit noisier than the intake. It has a subtle warbling sound that changes when you move the unit, and occasionally it sounds like it is very briefly slowing/fluttering for a second, before speeding up again. There is no buzzing or rattling as I've heard about elsewhere. Is this just something I'll have to learn to live with? Do they all make some form of noise over and above the whisper you would expect from small fans?

Here's a link to it on YouTube. Bear in mind that this is held close to the unit so is quite loud anyway.

Rayray · Aug 23, 2017

Like you, I have seen comments about this over a year period.
I'm not the best to answer this, being hard of hearing, and I know you'll get better answers from other members. I do have several ST16s, built and sold in different time periods. Inside or outside, their fan noise never intrudes. This is a personal matter of course.

If a fan rattles or squeals, I would have a problem. You are the best judge of what is acceptable to you.

Steve Carr · Aug 24, 2017

Baishy said:
Do they all make some form of noise over and above the whisper

I have one controller that makes a similar noise when I turn it at a certain angle. When I hold it level it gets quiet. It can be caused by a bad sleeve bearing or the fan may be hitting the housing. When dealing with that on a computer I have added a drop of 3-in-1 oil to the bearing and it seems to work well for a long time. Eventually the fan will need replaced.

PatR · Aug 24, 2017

Sounds like it might be slightly rubbing a cross piece. Won't hurt anything. If the sound doesn't annoy much don't worry about it. Just use it.

CraigCam · Aug 24, 2017

Try getting a can of air and blast it. That can help. They are pretty crappy made in China fans. Today I'm going to my great local electronics shop to see if there is a better replacement for my now very noisy over one year old original St.

Baishy · Aug 24, 2017

If anyone has what they consider to be a 'normal' sounding ST16 and has the time to post a sound clip I'd really appreciate it. I'm finding the noise quite annoying and distracting, but equally it's probably an element of dripping tap syndrome whereby I'm focused on it and it annoys even more!

I've emailed Yuneec CS UK (who I hear are very good), but it would be good to have a comparison if anyone has the time. I appreciate it'll be difficult to compare with just a sound clip to go on, but at least I may get a sense of whether I should push them to fix it, or just get over it! Thanks all.

PatR · Aug 24, 2017

The fans, even working perfectly, are not silent. They "whir" if for no other reason that due to the mechanical effects of something rotating at high speed on a bronze bushing. They move air, rapid airflow creates turbulence, which generates sound. SO even when everything is perfect, and I think mine are in my second 16, they are not silent and always maintain a latent background noise when functioning. Sort of like a floor fan running in your living room but not quite as discreet.

My first H very clearly demonstrated an "interference fit" One fan was quite loud and the sound indicated the blades were rubbing on something. You could actually feel light vibrations from the location of the particular fan. It was more than irritating, in fact a little embarrassing. Took a bit to get around to it but noting the side that made the most noise and replacing that fan was both quite simple and ended up making the first 16 generate a sound level similar, but not exactly the same as the second 16.

The fans are cheap and ordering one or two from Yuneec to have on hand in the event one fails or you desire to change one or both out to learn the effects of the change is not a bad idea. Certainly a heck of a lot cheaper than the shipping fee for sending a 16 back to Yuneec, and you would have it back up and running again in an hour or so instead of waiting weeks to get it back.

AH-64 D · Sep 1, 2017

How easy is it to change out ST-16 fans? My ST-16 is an early model. One of its fans has begun squawking in the way a cooling fan squawks when it has a bad bearing and is getting ready to seize.

PatR · Sep 2, 2017

Very easy. Remove the back from the ST-16 and lay it over. The rubber grips must be removed to access case screws under them. They are in recessed holes and the holes may be covered with a sticky film. The fans are in plain view. The electrical connection is a mini JST plug. Note the fan orientation before removal to assure you replace it with airflow in the correct direction.

AH-64 D · Sep 2, 2017

Thank you PatR. In addition, thanks for suggesting joining this forum. There is a lot of useful information here.

PatR · Sep 2, 2017

You're welcome, twice over

AH-64 D · Sep 2, 2017

Oh, Bleep...Short of asking Yuneec service, can anyone please suggest a source of replacement cooling fans for the ST-16? I can open the transmitter case and lubricate the fans that are in there, but I would rather replace them.

PatR · Sep 2, 2017

Try CarolinaDronz, Terrestrial Imaging, and Vertigo Drones.

You may find that just opening up the case and slightly re-position the fan or the cross bracket above it will cure the problem.

AH-64 D · Sep 5, 2017

Waited until today to call Carolina Dronz. They said I would have to get fans from Yuneec because they did not provide them to dealers. I then emailed Yuneec in Canada and am awaiting a reply.

CraigCam · Sep 6, 2017

It's not a proprietary fan. If you look at the size and voltage and pin out it can be ordered from Mauser or a good local electronic shop. I've found ear plugs work well to eliminate fan noise and stop the mind wandering into obsession.

AH-64 D · Sep 6, 2017

Good point CraigCam. Having once had to maintain a lot of equipment requiring cooling fans, my ears tend to seek out failing fans before something expensive happens. I was being lazy and trying to purchase plugin replacements, but I will source them elsewhere if necessary.