Benchcel Robot Stack Weight Limit?

We have a couple of Benchcel systems that we have used for plate filling and labeling for a long time, but recently we’ve had some issues with one failing to upstack into an already mostly full stack. Does anyone know the weight capacity of the actual robot? These are 2.2mL plates with about 1mL of liquid in them, so a full stack is quite heavy.

Completely anecdotal, but we had a BenchCel many years ago that would keep stacking plates into a stack even when it was “full” without stopping. We’d label hundreds of plates at a time. At one point we forgot about it for a bit and it stacked the plates to the ceiling and was pushing an acoustic ceiling tile up into the ceiling and still going. These were dry plates, but it was lifting at least 200 384-well PP plates without issue. V11 made some good hardware.

@dcmay or @Pete may know if there was actual advertised weight limit.

Edit: I should mention, it could be the plates slipping in the robot gripper, that’s a labware type setting, you can have it grip harder when lifting a stack. Generally when this happens you’ll see a small scratch in the plate if it slipped in the gripper while upstacking.

@cmcgregor I can not find the weight limit for the grippers on the Benchcel. In the past, I had a customer that had a plates with a metal cover on each and it was able to move them without issue.

Thanks for the responses! It did end up being a grip issue - the gripper fingers were not parallel, so once I got that sorted out there have been no more problems.