> ## Documentation Index
> Fetch the complete documentation index at: https://docs.almond.bot/llms.txt
> Use this file to discover all available pages before exploring further.

# Gravity Compensation

> Hold the arms weightless so you can move them by hand — from the web control panel or the CLI.

Gravity compensation holds both arms weightless so you can move them freely by hand. Each free joint is commanded with zero stiffness, velocity damping, and a feedforward torque that cancels the arm's modelled gravity — so the arm neither sags nor springs back. It's the easiest way to pose the robot, check its range of motion, or hand-guide it.

You can run it from the **web control panel** or the **CLI** (`axol gravity-comp`).

## Before you start

* **Axol installed** ([one-command install](/installation)) and the robot powered on.
* **CAN up and motors verified**. The control panel handles this on connect; on the CLI run [`axol can.setup`](/cli/can-setup) once, then check a motor with [`axol motor.info`](/cli/motor-info).

<Warning>
  The arms go compliant the moment this starts — be ready to support them so they don't drop.
</Warning>

## Run it

<Tabs>
  <Tab title="Control Panel">
    <Steps>
      <Step title="Connect the robot">
        Connect the **Axol Host** — the panel connects the robot automatically (press **Connect** on the **Axol** tile if needed). Gravity comp needs only the robot connection — no cameras. See the [Web Control Panel guide](/guides/control-panel#connections).
      </Step>

      <Step title="Select Gravity Compensation and Start">
        Pick **Gravity Compensation** from the operation selector and press **Start**. The arms go weightless immediately. Press **Stop** to hold them rigid again.
      </Step>
    </Steps>
  </Tab>

  <Tab title="CLI">
    On the robot machine:

    ```bash theme={null}
    axol gravity-comp                                 # all 7 joints free, both arms
    axol gravity-comp --right_channel null            # left arm only
    axol gravity-comp --kd 1.0                        # heavier damping (less floppy)
    axol gravity-comp --free_joints [WRIST_3]         # only WRIST_3 free; the rest held rigid
    ```

    Press `Ctrl+C` to stop. Use `--free_joints` to float only the named joints while the rest of the arm holds its pose — handy for isolating one joint at a time. See the [`gravity-comp`](/cli/gravity-comp) reference for every flag.
  </Tab>
</Tabs>

<Tip>
  If an arm sags or pushes back, the gravity model needs tuning — adjust the per-joint `mass` and `com` fields on `AxolConfig`. See [Gravity compensation](/api/robot#gravity-compensation).
</Tip>

## Next steps

<CardGroup cols={2}>
  <Card title="Teleoperation" icon="gamepad" href="/operations/teleop">
    Drive the arms from a VR headset instead of by hand.
  </Card>

  <Card title="gravity-comp reference" icon="terminal" href="/cli/gravity-comp">
    Every flag — free joints, damping, per-arm channels.
  </Card>
</CardGroup>