Siege Catapult

import { createAsset } from 'https://gaitkit.com/cdn/siege-catapult.mjs';

const siegeCatapult = createAsset();
scene.add(siegeCatapult);                      // rests on y = 0, front faces +Z

// 'arm' pivots on its hinge: -8° to 100° around x
siegeCatapult.getObjectByName('arm').rotation.x = THREE.MathUtils.degToRad(-8);

import { useMemo } from 'react';
import { createAsset } from 'https://gaitkit.com/cdn/siege-catapult.mjs';

export function SiegeCatapult() {
  const model = useMemo(() => createAsset(), []);
  return <primitive object={model} />;
}

# Import siege-catapult.glb (download below). Moving parts are separate nodes, pivoted on their hinge.
$SiegeCatapult/arm.rotation_degrees.x = -8

// Import siege-catapult.glb with glTFast (com.unity.cloud.gltfast).
transform.Find("arm").localEulerAngles = new Vector3(/* x: */ -8, 0, 0);