Jitering servos

Support Servo controllers and servos
1

Hello everyone,

I’ve searched the forum but couldn’t find information on my specific issue—or at least not such aggressive behavior.

I’m using a Mini Maestro 18-Channel USB Servo Controller (Assembled) with firmware 1.02. It’s mounted on a custom-designed platform inspired by various designs I’ve seen. However, as soon as I engage any of the secondary servos, the system starts jittering uncontrollably.

Here’s a video I uploaded to demonstrate the issue:
YouTube Video
At start i only select the foot servo and move it, then slect the middle servo and move it some jitter is showing, as soon i connect the third jitter beggins very agressive, as soon i disconnect the last 2 the jittering stops.
I can power all foot servos no jittter as soon i power any other it the starts.

Initially, I suspected it might be a power supply issue, but I’m using a bench power supply providing 6.5V at up to 15A. This should be sufficient for the Tower Pro MG995 servos—at least for a single leg.

Does anyone have suggestions on how to address this problem?

Thank you!
Tiago Carita

2

Hello.

The most common cause of jitter like that is probably a power issue, so looking at that first was a good idea. It sounds like you can use all 6 of the “foot” servos at the same time without issue, but if you just use 3 servos on a single leg, it causes them to jitter. If that’s the case, it might have something to do with the mechanics of the system (which affect the load on the servo) instead. For example, maybe in certain positions it has less mechanical advantage, causing excess torque on the servo, or maybe some of the screws on those joints are too tight, causing them to pinch and require too much torque to overcome. Does the problem still happen if you run the servos separately from the assembly with no load on them?

Brandon

3

I will disasemble one leg to check that out…

4

some servos burned no sure why, the board is ok, and somo of the good servos jitter with normal code.

So i do need new servos :frowning: