<mujoco model="50-double-universal-joint">
<compiler angle="radian" autolimits="true"/>
<option timestep="0.0001" integrator="implicitfast" iterations="50" cone="elliptic" impratio="10" gravity="0 0 -9.81"/>
<size memory="64M"/>
<worldbody>
<body name="shaftA" pos="0 -0.04 0.1"><joint name="j_A" type="hinge" axis="0 0.866 0.5" damping="0.002" frictionloss="0"/><inertial pos="0 -0.06527544807 -0.03768671064" mass="0.1526871896" fullinertia="0.0003536159294 0.00009461569245 0.0002613185944 0 0 -0.0001443697411"/><body name="cross1" pos="0 0 0"><joint name="j_c1a" type="hinge" axis="0 -0.5 0.866" damping="0.0005" frictionloss="0"/><inertial pos="0 0 0" mass="0.01852552176" fullinertia="0.000001424214777 0.000002429786933 0.000001759336172 0 0 5.805976038e-7"/><body name="middle" pos="0 0 0"><joint name="j_c1m" type="hinge" axis="1 0 0" damping="0.0005" frictionloss="0"/><inertial pos="0 0.04 0" mass="0.09365590355" fullinertia="0.00005330145155 0.00001871530266 0.00007119096129 0 0 0"/><body name="cross2" pos="0 0.08 0"><joint name="j_c2m" type="hinge" axis="1 0 0" damping="0.0005" frictionloss="0"/><inertial pos="0 0 0" mass="0.01852552176" fullinertia="0.000001424214777 0.000002429786933 0.000001759336172 0 0 -5.805976038e-7"/></body>
</body>
</body>
</body>
<body name="shaftB" pos="0 0.04 0.1"><joint name="j_B" type="hinge" axis="0 0.866 -0.5" damping="0.02" frictionloss="0"/><inertial pos="0 0.06527544807 -0.03768671064" mass="0.1526871896" fullinertia="0.0003536159294 0.00009461569245 0.0002613185944 0 0 0.0001443697411"/></body>
<body name="frame" pos="0 0 0"></body>
<geom name="floor" type="plane" size="1 1 0.1" contype="0" conaffinity="0" group="1"/>
</worldbody>
<equality><connect name="eye1" body1="cross2" body2="shaftB" anchor="0 -0.01 -0.017321" solref="0.002 1" solimp="0.95 0.99 0.001"/><connect name="eye2" body1="cross2" body2="shaftB" anchor="0 0.01 0.017321" solref="0.002 1" solimp="0.95 0.99 0.001"/></equality>
<contact><exclude body1="cross2" body2="shaftB"/><exclude body1="cross2" body2="shaftB"/></contact>
<actuator><velocity name="drive" joint="j_A" kv="2" forcerange="-5 5"/></actuator>
</mujoco>
