TableSyrup

IF YOUR SERVO MOTOR CLICKS/BUZZES THIS MAY BE YOUR FIX

Ok, so I cracked open a servo motor with the infamous clicking/buzzing and found the issue.

There is a small brass 'key' that is pressed onto the motor shaft.
What happens is over time the force from the worm gear pushes the key back, OR, the end cap inside the motor wears, allowing the shaft more play (Or both)... so when direction is reversed, the gear is then pulled away from the key and it disengages. Messing up your world.

NOTE: In regards to step one, I am recommending using a glue remover / un-cure.
I had a replacement servo and was just doing this to see if they could be fixed, so I rocked my servo head back and forth until it let go, which slightly broke just the tip of the gear shaft off. I was able to epoxy the head back on when done, but I DO NOT recommend trying to wiggle it off... if you break the shaft off lower, there is no fixing that unless you sleeved the entire shaft and glued all of that.

Here's the fix:

1) Remove the servo head (The white plastic piece that engages with the levers)

This is the most difficult step. Go to a hobby shop and get some glue remover / un-cure.
I am not positive this remover will work, as the chemistry depends on the glue, but it might.
Heat may be another option.
If I do discover what method is best for removing the head, I will update this how to.

2) Open the servo case. There are clips on either side of the electrical connector, and a few more around the outer edge of the case.

3) Remove the motor. It is simply pressed down into place.

Be sure to note which side is UP. If you flip it over, it's a DC motor, and I presume it would run backwards. This could be very bad and you might end up breaking tabs and stuff on the duct assembly.

4) Slide the plastic worm gear off the shaft.

5) With a pliers, slide/pull the brass key off the motor shaft. (Roughly note it's position)

6) Crimp the key a bit to close the hole tighter.

7) Install some washers on the motor shaft, this will make up for any play in the shaft. (I used 5 small stainless washers)

This would prevent the key from being able to slide any closer to the motor in the future, or due to play in the shaft.
Be sure to leave a hair of play in it.

You could alternatively skip the washers, and just be sure you have the motor shaft all the way in when positioning the key, but I opted for the added step in order to reduce the possibility of future issues.

Honestly, washers or not, either way you should be good.

9) Lay the key on a solid surface and press the motor shaft down into it.

10) Slide the key down the shaft - use the worm gear as a rough guide.
The shaft will have some play. If you slide it too far, you can just slide it back out a bit, but be careful not to do this too much, as the key is simply a press fit, and the more you move it the more it will loosen up.

11) Reassemble. Reinstall.

Hope this helps someone out !!!!

tmf2004

iTrader: (15)

so the washers keep the plastic end from having play therefore thats where the clicking comes from?

TableSyrup

I just modified the post to clarify a bit.

The issue is caused when the key slides back away from the worm gear, disengaging it... that click you hear is the gear skipping across the edge of the key. I believe this is caused by play in the motor shaft, probably caused by wear in the end cap inside the motor.

Category5

hmm, curious if that really did the trick because ill be honest I just simply took mine apart, cleaned them out just removing the old grease, reapplied new grease to everything, snapped the motor back into place which let me add was not clipped into place as it should have been, (noticed that when putting it back together and seating the motor) and its been 100% ever since! its been almost 9 months. Awesome great idea though! I see why you came up with the idea and it was smart!

TableSyrup

In my case, I verified the key was able to separate from the worm gear, and that it had been doing that, as the gear was chewed up a bit at that end.

So far it is working fine.I've cycled it through a whole bunch of times