Solved Whizzing servo

Hex23

Member
Hello guys. Its me again. So i just finished building ft racer and just waiting for a clear day for maiden. I was doing some tests then my right aileron just start whizzing and i lost control in it. Is it broken or can i fix it without opening the wing?
This is my electronics
1400kv motor
40a esc
Flysky 6ch rx with byme A gyro
2200mah 3s
4x 9g servos with the ailerons connected to Y cable
I had similar problem before this build, (also on the ailerons) where the servo just start making noise and then give up. It still has power in it cuz when i input on the tx it still makes a sound like it was trying to move. I will attach videos and a pic of the servos that i own.
 

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Piotrsko

Master member
Firstly move the plug over to another channel so you can determine if it's the servo or the reciever. See if you can gently move the output arm without crunchie noises. Anything else test wise will get very expensive rather quickly
 

Hex23

Member
Firstly move the plug over to another channel so you can determine if it's the servo or the reciever. See if you can gently move the output arm without crunchie noises. Anything else test wise will get very expensive rather quickly
I did try putting it in other channels and on the other rx as well. But it still whizzing😬
 

Hex23

Member
Sounds like the gears are stripped.
Yeah. . . Earlier i took a closer look on the 1st 2 servos that had the same whizzing and cracking sounds. A gear was lose. So it might be the same on this servo huh?
I recently bought 10pcs of those servos and 3 of them are already like this. Did i bought a bad batch or should i change other electronics? And would a metal gear servo change anything?
 

Mr Man

Elite member
Yeah. . . Earlier i took a closer look on the 1st 2 servos that had the same whizzing and cracking sounds. A gear was lose. So it might be the same on this servo huh?
I recently bought 10pcs of those servos and 3 of them are already like this. Did i bought a bad batch or should i change other electronics? And would a metal gear servo change anything?
Metal gear servos are a lot stronger and are less likely to strip.
 

Hex23

Member
Metal gear servos are a lot stronger and are less likely to strip.
Is it common for servos to strip? Im pretty sure theres not much tension on them.
Im gonna change it with plastic for now and hope for the best. Thanks as usual!
 

Mr Man

Elite member
Is it common for servos to strip? Im pretty sure theres not much tension on them.
Im gonna change it with plastic for now and hope for the best. Thanks as usual!
Yes, if you over-work them or yank them they can break.
 

Foamforce

Elite member
Are they blue servos from Amazon with a name that consists of arbitrary letters? Yes, that’s normal.

My first experience was with those servos. I was having a difficult enough time learning to fly and then my plane would occasionally go into a death spiral. After the crash I would test all the servos and try again. They would all appear to work. Then one day while I was flying, I noticed that my elevator had stopped working. I verified that it wasn’t working by flying by slowly was wagging the elevator. Fortunately it was well balanced, so I could fly with throttle alone. After landing, I tested again and the elevator worked again! So then I say and wiggled it back and forth for five minutes until it happened again. The bump from landing/crashing would free it up, which is why I would never see the problem post-crash.

Now, if I ever see a servo act funny and it’s not immediately obvious why, I trash the servo. Also, I use better servos. At very least, TowerPro branded blue servos. Or better yet, the cheap Emax servos, or any MG90 servo.
 

Hex23

Member
Thanks for the reply👍 Mr man and i thinks that it is a lost gear or something. And when i power it on it automatically start whizzing but no movement even i input on the tx.
I will try to shake it and see if it works. Will have to take out if it doesnt.
Kind of heart breaking to cut out the foam when i just finished painting it. Some luck huh😭 but better it happens while on ground.
Btw this is the servos that i use.
 

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AIRFORGE

Make It Fly!
Moderator
Thanks for the reply👍 Mr man and i thinks that it is a lost gear or something. And when i power it on it automatically start whizzing but no movement even i input on the tx.
I will try to shake it and see if it works. Will have to take out if it doesnt.
Kind of heart breaking to cut out the foam when i just finished painting it. Some luck huh😭 but better it happens while on ground.
Btw this is the servos that i use.
I've repaired a lot of servos in the past 45+ years.
You can take it apart by removing the 4 screws in the bottom. If it's a stripped gear, you might be able to replace it. You'll need to do a search for replacements. It's a simple fix if the parts are available. It might also be more cost effective to just buy new, better servos.
 

Houndpup Rc

Well-known member
Yeah. . . Earlier i took a closer look on the 1st 2 servos that had the same whizzing and cracking sounds. A gear was lose. So it might be the same on this servo huh?
I recently bought 10pcs of those servos and 3 of them are already like this. Did i bought a bad batch or should i change other electronics? And would a metal gear servo change anything?
Yeah I have the same servos.....They strip all the time:mad: I got these and they seem much better! Wish they weren't out of stock😢
 

Houndpup Rc

Well-known member
Be aware if you deside to get some metal gear 9g servos that the MG90S say that they are metal gear, but its only the main servo arm drive gear the rest are nylon(they still seem better than the blue ones.) The MG90D's are fully metal gear!
 

Houndpup Rc

Well-known member
Thanks for the reply👍 Mr man and i thinks that it is a lost gear or something. And when i power it on it automatically start whizzing but no movement even i input on the tx.
I will try to shake it and see if it works. Will have to take out if it doesnt.
Kind of heart breaking to cut out the foam when i just finished painting it. Some luck huh😭 but better it happens while on ground.
Btw this is the servos that i use.
You can also tell if its stripped by grabbing the arm and moving it a bit, if it moves without resistance its broken.
 

Hex23

Member
Yeah I have the same servos.....They strip all the time:mad: I got these and they seem much better! Wish they weren't out of stock😢
Thanks for the info. I will take a look on shop if its available👍
 

Hex23

Member
You can also tell if its stripped by grabbing the arm and moving it a bit, if it moves without resistance its broken.
Thanks. I will try metal servo for the next build for now i will try and fix the racer👍 And yeah it has no resistance on it. Got to take it out😐
 

Piotrsko

Master member
Not a cheapo servo fan.. if you have access to the bottom screws you could disassemble while still in the plane and replace the gears or whole assembly with new bottom assembly. Have had the top gear mounts break in a crash, but then the fuse was torn up badly also