Limited Range of Motion in 'Elbow Flex' Motor on SO-100 Follower Arm

[ParzivalExtrimis]

Issue: Limited Range of Motion in 'Elbow Flex' Motor on SO-100 Follower Arm

Description

In my build of the SO-100 arm, the follower arm exhibits an issue where the motor labeled 'elbow flex' is restricted to a movement range of approximately 90 degrees from the rest position.

Steps Taken to Troubleshoot

I have attempted the following troubleshooting steps:

• Checked the servo separately: The servo itself functions correctly and can move the full 360-degree range without issues.
• Tested manual movement: Manually tested the servo under normal teleoperation conditions with the weight of the arm.
• Re-calibrated multiple times: Repeated calibration to see if the issue persists.
• Modified calibration JSON manually: Editing the JSON file generated after calibration had no effect. The homing_offset field is the only one that causes any noticeable changes, but it only shifts the relative position of the follower to the leader, which is not a viable solution.
• Swapped servos: Replaced the servo with a new one to rule out hardware failure, but the issue remains.

Expected Behavior

The 'elbow flex' motor should be able to move the full intended range, similar to the leader arm, without being restricted to 90 degrees.

Actual Behavior

The motor is constrained to only about 90 degrees of movement from its rest position, despite the servo itself being capable of full rotation.

Additional Notes

• The issue seems to persist despite changes in hardware and re-calibration.
• There may be an issue with how the calibration data is applied or interpreted.
• Any insights into possible firmware, software, or mechanical constraints would be appreciated.

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Would appreciate any help or guidance on resolving this issue!