There are two types of issues related to calibration: technical issues that block the calibration processes and technical issues related to the robot's movement during a protocol run.

Issues during calibration process

Pipette calibration failure

The most common issues during pipette calibration are: 

  • Pipette colliding with the tip probe 

  • Pipette missing the tip probe

If the pipette is missing the tip probe:

  1. Complete a factory reset of pipette calibration and retry pipette calibration

  2. If the issue persists, complete another factory reset of pipette calibration and redo deck calibration (make sure you use Opentrons tips for deck calibration). Then retry pipette calibration.

  3. If the issue persists, contact technical support, let the team know the troubleshooting steps you've tried so far and a video of the failed calibration, and request the next steps.

If the pipette has collided with the tip probe:

  1. First visually check all the switches on the tip probe to confirm the switches are in the proper orientation and that they haven't sustained any damage (observe reference images below to determine proper orientation).

  2. Complete steps 1-3 above.

Improper orientation:

Proper orientation:

Labware Calibration Failure

The most common issue to occur during the labware calibration process is a crash. This is a severe issue, as crashing causes corrupt calibration data. If you experience a crash during labware calibration, reupload your protocol and restart the labware calibration process. You should investigate for the following root causes:

  • Does the labware definition loaded in the protocol match the physical labware in the slot?

  • Did you complete pipette calibration?

If you have completed the above and are still having issues, follow these steps in order:

  1. Complete a factory reset of pipette calibration and labware calibration

  2. Complete deck calibration (make sure to use Opentrons tips)

  3. Reupload your protocol and retry calibration

If this method does not resolve your issue, one more thing you can try is using the calibrate-to-bottom feature by following these steps:

  1. Connect to your OT-2 through the Opentrons App

  2. Scroll down to "Advanced Settings"

  3. Find the feature named "Calibrate to Bottom"

  4. Toggle the switch on (the color will change from gray to blue)

  5. Power-cyle your OT-2

Once the robot is powered back on, the robot will be loaded with this feature. Now, when you calibrate labware, the app will prompt you to lower the tip to the bottom of the well instead of a position even with the top.

If there is a specific labware that the pipette is colliding against during the labware calibration process, we recommend the following workaround:

  1. Before commanding the pipette to move to that particular labware, move that labware from the deck

  2. Command the pipette to move to the empty slot

  3. Jog the pipette so there is room to put the labware back in its slot

  4. Jog the pipette to position and calibrate as normal

Calibration issues during a run

Troubleshooting Movement Issues

There are many reasons your OT-2 can move erratically during a run. It is important to understand that troubleshooting movement issues like this can require a good deal of upfront investigation to diagnose and resolve. Ultimately, if you are experiencing issues and are troubleshooting (whether independently or with assistance from technical support), it's a best practice to capture images/video of the behavior and clarify the following details:

  • What commands in the protocol are being executed at the time of the crash?

  • Which pipette is experiencing the crash?

  • Which mount is that pipette on?

  • Which labware is the pipette crashing against?

  • How is this labware loaded in the protocol?

  • What is the expected behavior?

Having images/videos of the behavior as well as a strong command of the above details related to your issue will help significantly in the troubleshooting process, especially if you reach out to technical support.

Crashing During a Run

Robot crashing refers to when the robot crashes pipettes into labware or crashes the entire pipette carriage against its own physical boundaries during a run.

The first most common reason for crashing during a run is corrupt calibration data. If you did not complete labware calibration or pipette calibration before the run, we suggest you reupload the protocol and complete these calibration processes. Furthermore, ensure that 1) the labware is properly mounted in the slot, and 2) during the calibration process, that there are no collisions, neither between the pipettes and the labware, nor the pipette carriage with its physical boundaries. Rerun the protocol and observe whether the issue persists. If the issue does persist, you may follow these steps for a more exhaustive method of rewriting calibration data:

  1. Complete a factory reset of pipette calibration and labware calibration

  2. Complete a deck calibration

  3. Reupload your protocol and complete labware and pipette calibration

  4. Observe whether the erratic behavior persists

The second most common reason for crashing is that the defined labware in the protocol does not match the physical labware on the deck. To verify, you should check your protocol to identify the definition being used, and confirm through our Labware Library that the definition matches the labware on the deck. For instructions on how to use the library, refer to the following article: Using the Labware Library

Finally, the root cause of the issue may not be that the robot is crashing in error, but that an error in the protocol is commanding the robot to crash against labware or against its physical boundaries. In this case, or if the above troubleshooting did not resolve your issue, contact the support team and we will work to 1) identify whether the crashing issue is reproducible on a robot in our office, and 2) work with you to resolve your issues.

Positional Accuracy

Issues with positional accuracy refer to the pipette's failure to move to the calibrated position in a well during a run. This is a relatively uncommon movement issue, and you should seek assistance from technical support to troubleshoot and resolve these types of issues.

Pipette Drifting

Pipette drifting refers to when a pipette moves further from the center of wells as it iterates through a column/row of a piece of labware. 

The two most common root cause for this behavior are mismatched labware definitions and corrupt deck calibration. To investigate the mismatched labware definition issue, you should investigate whether the labware definition loaded in your protocol matches the physical labware on the deck. To troubleshoot deck calibration, you should redo deck calibration, reupload the protocol, redo pipette and labware calibration, and rerun the protocol. If the issue persists, contact technical support.

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