Issue with Micro Maestro 6x and Mini Servo FT1117M

Support Servo controllers and servos
1

Hello,

I am building a semi-humanoid robot and am experiencing some servo issues in the process. Hopefully someone can point me in the right direction to resolve this!

Short description
I have created a construction that allows a robot head to turn in 3 directions (pitch, yaw and roll). The construction is supported by bearings that allow the head to move freely. The construction uses 2x Feetech FT1117M servo’s for pitch and roll. The yaw axis uses a larger Feetech FS5115M servo. The robot consists mostly of 3D printed PLA parts. The FT1117M servo’s are used because they are compact enough to fit the design, as larger servo’s would make it more complex to fit (and the added torque would not be required).

Example
Example3023×929 191 KB

FT1117M servo’s are marked with 2 red arrows in the image.

Issue
I am currently testing in a temporary situation if all servo’s work as expected using a Micro Maestro. The final solution will most likely use a different controller (PCA9685 for example). However I’m experiencing some significant jitter issues when the FT1117M servo’s are idle when using the Micro Maestro (6x). The servo’s don’t have any issue moving around and don’t seem to struggle when making a move. The moves don’t require a lot of torque, and bearings are also used to ensure smooth motion.

When the FT1117M servo’s move, they behave as expected. However, when stopping, they start humming or jittering heavily around the goal position. This happens more often around the “centered” position than the extremities. The FS5115M does not experience any of these issues and does not buzz or jitter around the goal position, even when used in combination with the two FT1117M’s on the Micro Maestro. Manually nudging the servo’s gently stops them from buzzing sometimes.

Electrical & control setup

  • Turnigy 4000mAh 3S LiPo > 6V 2A Voltage regulator (Pololu S18V20F6) + 1000uF capacitor across 6V output > Micro Maestro
  • Micro Maestro is also hooked up to a PC via USB (Windows 11, using Maestro Control Center 1.5.2.0)

Thanks in advance!

2

Hello.

Some amount of humming and jittering is normal for most servos when they are under load. Do the servos behave the same way if there is no mechanical load connected to them? Even if your application does not seem like it should require a lot of torque, it might still be substantial compared to what a mini servo like the FT1117M can handle. Some pictures of your actual setup that show all of your connections and a video of the behavior might be helpful. The forum does not allow users to post very large videos, but it does work well with videos linked from other sites (like YouTube or Vimeo).

Could you also try a different power supply to see if that has any affect? You could also test if this is a power supply issue by disconnecting everything from the Maestro except for one of the servos you are having trouble with and trying it out.

- Patrick