Dynamixel XC series homing offset

I noticed in the documentation that the offset can only be within the range -1024 to 1024. I am then not entirely sure how I can bring the position down from 3000 to 100.
When I set the homing offset to 2900, it just sets it back to 0.
So I am wondering how I may be able to change the position like this.

Reasoning is, I have a homing switch, and at that point I would like to drop the position to around 100. The reason I don’t want to go for lower than that is because if the motor does by some chance go below 0, it will then think I need to go the opposite direction when applying a position.

DYNAMIXEL Servo: XC330 and XC430

At this point, your robot situation is “beyond software interventions”, it will need “physical/mechanical interventions”.

I had encountered similar situations in the past and devised this “minimal” mechanical intervention procedure. Below is a picture of my “oldie” AX-12 arm, just to help visualize the proposed procedure:


  1. With POWER OFF to the impacted servo, remove the 4 mounting screws on the HORN side, and leave the other 4 mounting screws in the back as is. Essentially, we want only to disconnect mechanically the frame part from the servo’s horn, and not to disconnect an entire section of your robot.

  2. Then, Power back on the impacted servo, and go to Dynamixel Wizard. Clear to zero its Homing Offset (Add. 20) if previously used. Next set its Goal Position to 2048. The servo should go there unimpeded by the frame part.

  3. Now move the robot’s frame part towards its Physical Initial Position (or whatever position that you consider as the Physical Home Position for your robot (not for the impacted servo, because it is already there). Next, you are going to find a “sweet spot” for the frame part that is closest to your wanted Physical Home Position, and also at the same time the mounting holes on the frame part and the mounting holes on the servo’s horn are ALL ALIGNED with each other. Then put the Horn screws back on, to secure mechanical connections between your frame part and the servo’s horn.

  4. Lastly, you can adjust the Homing Offset parameter to fine tune the Physical Home Position of your robot’s frame part.

Obviously, if your robot is now built such that you cannot even do Step 1, then you are stuck, and you’ll really have to rebuild your robot.

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