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Problems with Micro maestro and XMG-996R servos

Hello folks. I am experiencing a situation with the XMG-996R servos (for a robotic arm) on Micro Maestro 6 channel controller. When powered up, maestro recognizes both servos. Maestro works well with only one 996Rservo. However, when I connect a second 996R servo and try to set the motion for the 996R servo in channel 0, the other 996R servo in channel 1 starts to move violently and uncontrolled and then moves to one of the extreme travel and locks in place doing a growling/humming sound. After that, neither 996R servos can be controlled with maestro. I have to disconnect power and reset the servos. Then when powered up and I try to set the movements they do it all over again. I’m powering the micro and servos with 5V 1A from a wall adapter. I jumped the VIN and the servo power in the Micro as per instructions, therefore using one power supply to run both the maestro and the servos. The maestro program doesn’t give me any error code.

At this point I have no clue why are these servos behaving like that. I will greatly appreciate feedback and info on possible causes and solutions. Many thanks.

Hello.

It sounds like you have a power issue. When you draw too much current (like adding the second servo), you are probably getting a dip in voltage, potentially browning out the servos (and Maestro if it is using the same power supply). We typically recommend budgeting around 1A per standard servo, but from a quick Internet search, those servos seem to be high-torque, so they might require more than that. I suggest checking the servo’s specifications from the manufacturer to see what the stall current is and plan for enough current to power both and a little extra for the Maestro.

-Derrill

Hello Derrill. Thank for the quick response. Indeed it was power. I switched to a 5V 4a supply and connected the 2 servos again and they work fine. In fact, I connected 4 servos and this time they all work fine. Thanks !!!

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