Overview: 

This guide is for users who find that their robot is moving too quickly. By using the procedure below you can slow down the robot's motor. This will decrease the speed at which the robot moves.

The speed of the robot’s motors can be set using robot.head_speed(). The units are all millimeters-per-second (mm/sec).

‘x’: lateral motion, ‘y’: front to back motion, ‘z’: vertical motion of the left mount, ‘a’: vertical motion of the right mount, ‘b’: plunger motor for the left pipette, ‘c’: plunger motor for the right pipette.

The combined_speed parameter sets the speed across all axes to either the specified value or the axis max, whichever is lower. Defaults are specified by DEFAULT_MAX_SPEEDS in robot_configs.py.

max_speed_per_axis = {
    'x': 600, 'y': 400, 'z': 125, 'a': 125, 'b': 50, 'c': 50}
robot.head_speed(
    combined_speed=max(max_speed_per_axis.values()),
    **max_speed_per_axis)


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Be Advised

Each axis of the OT2 has a speed of resonance. At these speeds, the machine will vibrate excessively.  The actual speed may be slightly different per machine based on part or assembly variances.

We found, through testing, to avoid certain speeds. We either go at a slower or faster speed than this to avoid excessive noise.

We have found this in many similar lead-screw driven machines; and usually the most common solutions are simply to avoid that speed.  Other solutions may be to change the lead screw pitch, the weight of the machine, or similar; however even after these modifications, there still may be a resonance issue but at a different speed value.

If this is in fact the case, and the noise is eliminated by either travelling faster or slower, we recommend to simply avoid that slow speed.

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