We are working on a Hamilton Vantage and using the Core Gripper to transport plates using Get Plate / Place Plate commands. The transport of the plate happens fine, but intermittently, we are seeing a “AX: Object already present” error. This occurs after the plate has been successfully placed at the destination location and after the arm retracts upwards above the location. It then prompts to open the gripper as though it thinks it is still holding the plate. I would like to get more context and what this error means and how to go about eliminating it.
Some things we have tried:
Checking the plate height in the labware definition vs. the actual physical height
Re-teaching z-height of the position.
Backing off the Place Press on distance
Adjusting the closed grip position
Adjusting the force used with the grip
One other curious thing is I have tried running this without any plate at all and have been able to reproduce it even when it wasn’t holding a plate. I thought potentially it was force feedback related but this would suggest something else…
@mueller68 @MikeMueller
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@BrandonBare_Hamilton
Any suggestions which settings to focus on to look to track down this issue? It is intermittent which has made it challenging - I’ll change a variable, test it, it will test fine, but then as I continue running it more it will show up again.
Most recently I adjusted the open grip width and made it narrower.
Thanks,
Mike
Hi @KellyTracy and @mueller68 ,
Can you inspect your QCG from the side looking specifically at the two tabs in the middle. These get pressed out when holding a plate which will then break the circuit that the channels use. This is how the QCG determines if it is holding a plate or not. It is possible that these tabs have been bent outward which is causing a false detection. They can be gently pressed inwards to correct as long as they were not severely bent from a crash. When not holding a plate, they should naturally push inwards and be making contact with the gripper itself.
Other things to try is to gently wipe the inside with a kimwipe or use a can of compressed air to blow out and dust or debris that may be inside the Core interface.
