Hi everyone,
Thank you all for the detailed responses - I appreciate the guidance as I work
through this!
A brief update - a student was utilizing the instrument tonight and, while
the sample went down into the magnet (after a few up and down cycles), it
appears TopSpin does not realize there is a sample within the magnet.
Troubleshooting thusfar has involved disabling the autosampler and trying to
utilize the lift option to manually eject. Unfortunately, it appears the
air pressure is not ample enough to eject the sample/spinner.
Does anyone have any tricks for this issue? I will be working on this an
hoping to resolve this as soon as possible. (and then get back to addressing
the other potential troubleshoots for the previous email's issues).
Thanks again everyone!
Jessica
Dr. Jessica M. Roberts, Ph.D.
Assistant Professor of Instruction
NMR Facility Manager
Department of Chemistry and Biochemistry
Ohio University
245 Chemistry
Athens, OH 45701
740.593.0038
jroberts_at_ohio.edu
________________________________
From: main_at_ammrl.groups.io <main_at_ammrl.groups.io> on behalf of Josh Kurutz via groups.io <jkurutz=uchicago.edu_at_groups.io>
Sent: Wednesday, July 26, 2023 7:44 PM
To: main_at_ammrl.groups.io <main_at_ammrl.groups.io>
Subject: [External] Re: [AMMRL] SampleCase loading errors
Hi Jessica.
I’m thrilled to see your post, as I’ve been bedeviled with a variety of
pneumatics problems with three new SampleCases. Your problem #1 was happening
to me ~5X/day shortly after it was installed a few months ago; we upgraded
our AVIII-HD with a SampleCase (24) to SampleCasePlus (60) this year. With
mine, I could watch the sample go down the bore, but I wouldn’t hear the
normal click sound. After several weeks of pneumatics adjustments, I think
we’ve finally got it under control. Because my autosamplers (and two consoles)
are new, I’ve been working with Bruker service. But their advice, while
providing useful insights, hasn’t solved my problems.
Quick question for you: is the upper part/rail of your autosampler a SampleMail3?
The internals are different from the SampleMail2, and we found that getting the
firmware to work with the SM3 correctly was an issue. Because I am seeing
similar pneumatics issues on three new autosamplers with SampleMail3s (two
SampleCases on new Neo consoles, one SampleCasePlus on an AVIII-HD nanobay),
I have to wonder whether there’s either an underlying design or firmware problem.
What helped/worked for me for your Problem #1, the “Repeated attempts at
sample insertion eventually all fail, and the queue stops” issue: setting
the “Reduced Hold Airflow for sample insertion” to 1600 l/h (instead of
the normal 4800). Process:
* Topspin “ha” and select “BSMS” to open the web interface into the BSMS.
* Select “Service” and log in as an admin
* From the main BSMS web page, navigate to “Sample Handling”…”Lift Control”.
* Under “Lift Control” you’ll see “Reduced Hold Airflow for sample
insertion” and “Hold Sample Airflow”.
* Hold Sample Airflow (normally 4800 l/h) governs the eject air flow
when the autosampler is bypassed (or if you have no autosampler).
* The “Reduced Hold…” setting is not visible unless you’d logged
in as a Service person. So until you log in, you might not even know this setting
is a thing.
I spent a tedious couple weeks gradually lowering this air flow setting and
determining whether the rate of insertion failure was improving. Then I spent a
couple days making bigger changes. Below 1600 lph, my samples had a hard time
ejecting, but things seem to work OK now that it’s at 1600. It hasn’t failed
because of this for a few weeks now, but we still get some samples the take two,
sometimes three tries at insertion.
Other things I checked:
* In the “Lift Control” page, checked that the BST was set to the right
length. (Mine had been set wrong)
* Adjusted the “timeout” time given to the sensor in the magnet. Bruker and
Banghao Chen (in a previous response to this question) recommended
lengthening it. Topspin error messages sometimes recommend this course of
action, too. We lengthened ours to 50 sec, but about all it did for us was
make our cycle of five insertion attempts take five minutes to fail.
* See HA/BSMS page “Sample Handling…SampleCase Calibration”…Timeout
setting to make this adjustment.
* Cleaned the bore (as suggested by others). But the lack of “click” sound
indicated it probably was a pneumatics problem, not a dirty sensor issue.
* I’m pretty interested in Casey’s suggestion of sonicating the
cap of the shim stack. I had no idea this was a thing! I know one of our
instruments had some goo on top of its shimstack that survived the normal swabbing
out of the bore.
* Checked house air. We’ve been having intermittent issues with house=
N2 in that lab. But Problem #1 occurs independently of house issues.
* Recalibrated the SampleCase lift setting with a short J-Young tube.
PROBLEM#2: I’ve encountered this in the manner Mike Groves pointed out: A
J-Young tube tricks the optics into thinking the spinner has reached its position
in the slider, so to pin that normally pokes inward to support the spinner is
inserted too early, preventing the spinner from getting secured in the slider.
I found it bounces downward and gets stuck in the transport tube, atop the white
lifting tube. I thought the problem was when the valve cap was white. I think we
tried taping them up with black electrical tape to make them dark, and maybe they
worked; it was an intermittent problem, so it’s a bit hard to tell. My users
figured out that for their purposes they could avoid j-Young tubes by wrapping a
bunch of electrical tape around their caps, so I haven’t tested this vigorously.
MY RELATED PROBLEM: On the two new Neos with SampleCases, we’ve been unable to
eject samples when the autosamplers are bypassed (the big red button is depressed).
These instruments are for manual use, and sometimes people want to use long J-Young
tubes or want to reduce the deadtime in kinetics me asurements by opting for manual
insertion. On BOTH instruments, the first time someone tried bypassing the autosampler,
they couldn’t get their sample out. We compensated by increasing VT air to overcome
the immediate problem. This was really weird, because I could take a normal non-J-Young
tube and insert/eject it fine with the autosampler, but when the autosampler is bypassed
the same sample fails to eject.
* In both cases, I’ve had to increase the “Hold Sample Airflow” from the
default 4800 l/h: to 6900 on one (500 US+ magnet) and 5600 on the other (Ascend 600 magnet).
* In both cases, the margin between “flow that fails to eject a sample” and “flow
that makes a sample bobble around a bunch” seems pretty narrow, percentage-wise: around 25-50 l/h.
* I recently found that setting it just a little too high was enough to make a
J-Young tube sway back and forth enough that during insertion, they’d get stuck on top
of the magnet.
One thing I’m confused by: Adjusting the Hold air for manual eject had no
apparent effect on the eject or insert behavior of the autosampler. It seems that
there’s some other air flow control at work, and I don’t see how it works yet.
I’d appreciate insights from the AMMRL community.
I hope this helps. I suspect there’s some common factor among all these issue that
should be fixed with a firmware update.
Thanks! - Josh
Josh Kurutz, PhD
NMR Facility Manager, Chemistry Dept.
https://voices.uchicago.edu/chemnmr/
jkurutz_at_uchicago.edu
From: main_at_ammrl.groups.io <main_at_ammrl.groups.io> on behalf of Roberts, Jessica <jroberts_at_ohio.edu>
Date: Wednesday, July 26, 2023 at 1:59 PM
To: main_at_ammrl.groups.io <main_at_ammrl.groups.io>
Subject: [AMMRL] SampleCase loading errors
Hello everyone!
I have currently been having issues while using the SampleCase autosampler on
my 500 MHz Ascend instrument. There are two major issues that arise:
1. SampleCase fails to load a sample into the magnet. Autosampler will retrieve
the sample, send it up and across and down into the magnet. After a few seconds,
the sample will be ejected (often times by a sound that seems alot like building
pressure in an air line). The sample will then sit with the lift on for a few
seconds before repeating the process. After a few failed attempts the sample will
error out on IconNMR.
2. There is a less frequent issue but I will include it in case it is relevant. I
have seen the SampleCase retrieve a sample from the carousel, lift it to the top
track where it remains momentarily, then it will be sent back down to the carousel.
This typically times out after a few repeatedly failing attempts.
A few notes I will say:
-I am located at Ohio University where it has been quite humid as of late.
My air dryer does not have an autoswitch but I have powered it on today and
intend to run it for a few days to see if it improves things.
-Initial issues were only observed with one ceramic spinner, so I thought it might
be a problem with the old reflective tape. Now it can occur with a spinner that
worked for the previous experiment. In the most recent instance, the loading error
did not occur for a standard proton but for the immediately following standard
proton with rotation.
-It sometimes seems sporadic. A user can submit samples without issues while another
will have problems and it is hard to reproduce as I try to troubleshoot.
-I have not yet had issues with manual sample loading using lift on/off on BSMS module
so I suspect it is autosampler related.
Thanks everyone!
Jessica
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