Hi all,
Due to some deck space constraints on our Vantage, we are attempting to utilize a custom mount to position the QCGs adjacent to the default channel tip waste in position 3 just north of the teaching needles (see pictures below).
I am trying to teach this new custom Z-position, however I am looking for guidance on how best to go about this, since I cannot see where the channels are within the QCGs to understand if I am too high or too low. When attempting QCG pickup, the channels enter smoothly, but no squeeze drives seem to activate, and the system stops to display the error below (limit stop not found).
I figure this means my z-height is too high still, but if I attempt to manually pick up the QCGs in order to feel how far off the channels are from it, I cannot move the QCGs upwards, as if the tips are already pinned at the bottom of the QCG holes. This makes me not want to move the z-height of the labware down any further. I received the same error when the z height was obviously too high and I could pick the QCGs up manually from the mount 5-10 mm to meet the channels in their stopped error state.
Is there a “sweet spot” above the bottom of the QCG “barrels” that must be aimed for? Or is aiming for the bottom the way to go? Any tips appreciated!
Thanks!
Hi @VantageHandler,
Here are instructions on teaching the QCG:
The A1 position on the QCG is in the center of the tool on the top. Use this position to determine x and y adjustments. Then, to teach the z height, pin the teaching needle against the top of the QCG. The desired z will be -116 mm from this z position. Test the QCG pickup and eject to positional accuracy.
Thank you,
Dan
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Thank you for these very helpful instructions!
I gave it a try and pickup looked great. On eject, the QCG was brought down to the mount height, the eject action was audibly heard, but the channels seemed to stick to the QCG slightly and finally “let go” while in the process of retracting upwards, resulting in the QCGs falling an inch or so before landing on the base.
I’ve seen this before with heavily used CO-RE I systems in need of a PM/stop disc replacement, but I’m curious if this same sticking can occur on CO-RE II systems, too.
The other thing I realized is that with the height of the top of my QCGs (~258mm), I understand I am above the instrument traverse height. I figure with the QCG placement being in the far right and far back of the deck, there are no obvious indications for potential collisions. The only exception is after an abort error with the QCGs in operation, as the system will place the QCGs back to park, and lower two channels to prompt whether the positions below the channels are empty. Can I adjust the height this action is performed at (or turn it off)? I’m not planning to run into many QCG errors, but it certainly will happen at some point, and I want to make sure I’m not setting the channels up to collide with the QCGs when it does happen.
Thanks!
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Hi @VantageHandler,
Glad to hear that did the trick to teach the QCG position. The sticking you mentioned can occur with CO-RE II as well, but I would first check the QCG itself. Make sure the four CORE adapters (the holes that the channels descend into to grip the QCG) are clean and free of debris. These can be rinsed with isopropanol or ethanol and wiped dry. If the issue continues, you can also try increasing your z-height slightly (+1-2mm) from the currently taught position and re-test for functionality.
As for the clearance issue, is the ~258mm coming from measuring the top of the QCG relative to deck, or from the clearance/warning dialog presented in the Method Editor from placing the Labware Definition on Deck Layout? If it’s the latter, then it is likely a non-issue as long as the QCG isn’t physically crossing the 245mm threshold. Unfortunately, that dialog/height cannot be adjusted as they are built into the background code.
Thank you,
Dan
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