Weird servo issue

[Nimyad]

Solar d772 servo, about a month old. When there's a load on the servo, like turning into something or when the servo is trying to keep the tires straight or just turning all the way, the servo starts to vibrate. It feels like a gear was skipping so I took it apart and all the gears are in perfect condition, so I'm thinking it's a motor problem or something?
You can see the vibration in the servo horn, it moves back and forth really quickly.
I ran the servo at 6 volts for a while and then bumped it to 7.4 volts, it's never been hotter than room temperature.
Any ideas what it could be? I know it's a cheap servo but I want to save it if I can.

[crawlhog]

do you have a BEC?

[Nimyad]

Yes I do, castle bec at 7.4 volts

[crawlhog]

is your servo rated for 7.4v?

[Nimyad]

yes it is, I could bring it down a little and see if it goes away I guess.

[Nimyad]

Took a look at it again today, it's not really a vibration. It literally feels like a gear is skipping but none of the gears show any signs of wear. What the heck guys?

[thatguy]

Does it stutter when you unhook the linkage ? Maybe a binding issue? If it stutters with nothing hooked to it. Will it go away with some trim adjustment? Some cheap dig. servos just hunt for center. How are the bushings the servo gears ride in ? A worn boss in the case or gear center can cause problems. Skipping teeth makes center move.

[Meatwad]

Cheaper servos sometimes have pot issues that can cause this.. seen it in the towerpro/towardpro servos.

[JokersWild]

Originally Posted by Meatwad

Cheaper servos sometimes have pot issues that can cause this.. seen it in the towerpro/towardpro servos.

X2 issues Prolly with the pot.....

[Nimyad]

What's the pot?

[Nimyad]

Looked it up, doesn't sound like that's the problem. Mine returns to center fine. It steers and works flawlessly until you put a load on it, then it feels like it's skipping a gear.

[Meatwad]

Yep pot= potentiometer

Originally Posted by Nimyad

Solar d772 servo, about a month old. When there's a load on the servo, like turning into something or when the servo is trying to keep the tires straight or just turning all the way, the servo starts to vibrate. It feels like a gear was skipping so I took it apart and all the gears are in perfect condition, so I'm thinking it's a motor problem or something?
You can see the vibration in the servo horn, it moves back and forth really quickly.
I ran the servo at 6 volts for a while and then bumped it to 7.4 volts, it's never been hotter than room temperature.
Any ideas what it could be? I know it's a cheap servo but I want to save it if I can.

Towards the beginning you say when it's trying to center, that it vibrates (wiggles?)... Usually a pot replacement helps.

[tdevilman2009]

how about checking were the pins for the gears ride i had one do that an the pin holes were oval shaped instead of round mine was a hitec 645 though with about six years of use as a throttle/brake servo on a tc3. hope this helps some

[Nimyad]

Originally Posted by Meatwad

Yep pot= potentiometer
Towards the beginning you say when it's trying to center, that it vibrates (wiggles?)... Usually a pot replacement helps.

It doesn't stutter just holding the tires straight but if the tires are straight and you push on them with your hand it does it.
I'll tear it apart again today and check the bushings.

[Nimyad]

Checked everything over again, it just doesn't make any sense. All the bushings and gears are fine but it still does it. Guess I'll order a new one.

[Nimyad]

Here's a video of what it does, it's lost most of it's power as well.
http://s791.beta.photobucket.com/use...338DA.mp4.html

[Cheatin]

Gears are spinning on the shaft? I dunno' but 100 bucks should fix it.

[JokersWild]

Tried to watch you video twice. All I saw was ad with Kathy Ireland. Sounds like you saved money on cheap servo and now its toast?

[Nimyad]

Originally Posted by Cheatin

Gears are spinning on the shaft? I dunno' but 100 bucks should fix it.

New servo it is.

Sorry for the video issues, I tried embedding it but that wouldn't work.

[tdevilman2009]

can u pull it apart an take some pics of the gears all cleaned an the inside top of the case. i know some gears are pressed fit together an have seen some fail at this point. kinda sounds like what it might b or check the gear on the motor i had a towerpro 995 i got in a trade deal that was doing that. best way to tell if it is the gaer on the motor is to pull apart an turn on the radio an recive center the pot till motor stop spining grab a small screwdriver an wedge it against the gear the turn the steering an see what happens