I've seen protein crystals bigger than that. Next time you do, send them my way, James.
Aaron ______________________ Aaron Finke European Spallation Source ERIC Instrument Data Scientist Data Management and Software Centre Asmussens Allé 305 2800 Lyngby Denmark Aarhus University Adjunct Associate Professor Department of Molecular Biology and Genetics Protein Science Phone: +45 25 50 39 41 E-mail: [email protected]<mailto:[email protected]> ess.eu<https://www.ess.eu> From: CCP4 bulletin board <[email protected]> on behalf of James Holton <[email protected]> Date: Tuesday, December 23, 2025 at 1:36 AM To: [email protected] <[email protected]> Subject: Re: [ccp4bb] stuck puck Thanks everyone for the excellent responses. I'm a little surprised, however, that this rather severe "gotcha" of a design flaw has never been addressed? Yes, Yes, I know: "Always Follow The Instructions", but this a pretty expensive penalty for such a small mistake. Also, I can't think of a single reason why there would be an advantage to having the space deep inside a shipping dewar be bigger than its neck. We just did some measurements on a warm CX100. The neck tube inner diameter is 70.58 mm and the puck cane I have in front of me measures 68.15 mm outer diameter. And, with a puck inserted out of alignment, the maximum sticky-outy diameter of the cane+puck is 71.33 mm. (basically: 3 mm wider, the height of the alignment bump) This is only a 750 micron difference! I've seen protein crystals bigger than that. If the next step is destroying the dewar, maybe one more thing to try would be using a sanding drum or other abrasive to widen the dewar neck aperture? You only need to take off ~0.4 mm. In fact, a felt cylinder painted with coarse grit diamond paste could make short work of that. Might even work cold. Now, I have no idea how thick that fiberglass tube that forms the neck is, but I suspect it is probably thicker than 0.5 mm. It is also a vacuum seal, an fiberglass dust is not good for you. But with adequate safety measures I think perhaps it could be done. Have I tried this? No. All the working dewars around me are not mine. I was also thinking, as a preventative measure, why not add padding? I bought some 1 mm thick teflon mesh and we dropped a single layer of it down inside. Took a few iterations (and it helps if someone on your team has very small hands), but the final sheet that fits measures 280.7 mm deep and 225.72 mm in circumference. This implies a ~72 mm internal diameter for the deeper cavity. This is ~4mm bigger than the puck cane, and 0.7 mm bigger than the misaligned cane+puck. A properly aligned cane, however, fits. Takes a few tries to push the teflon firmly against the walls of the lower chamber, but after that it goes in and out easily. With the added 1 mm of teflon on all sides, there is only 2 mm of room left: not enough for a mis-aligned cane+puck (the alignment bump is 3 mm). I expect that means it won't be able to pop out of place. Now, have we tried putting a cane with no retention pin into this dewar and gorilla tested it? No. I don't have a dewar I hate that much. But, seems to me that adding a teflon liner to your CX100 would be harmless, and perhaps save some of us all a lot of headaches in the future? Just an idea for your Holiday gift lists. -James Holton MAD Scientist On 12/4/2025 3:25 PM, Kevin M Jude wrote: James, this came up on the BB a couple months ago, look for the thread "[ccp4bb] Off-topic: call for suggestions to rescue a puck stuck in a shipping dewar”. From: CCP4 bulletin board <[email protected]><mailto:[email protected]> on behalf of James Holton <[email protected]><mailto:[email protected]> Date: Thursday, December 4, 2025 at 10:28 AM To: [email protected]<mailto:[email protected]> <[email protected]><mailto:[email protected]> Subject: [ccp4bb] stuck puck Anybody know any tricks for getting a puck cane out of a shipping dewar after it got shipped without the retaining pin? Asking for a friend, -James Holton MAD Scientist ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1<https://urldefense.com/v3/__https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1__;!!G92We9drHetJ8EofZw!edpCynZA0dj8pM3-dpzLTQbdQLdppxyxBvVAt6Q8B6tLTQwsVJgonW1Y68_WS8gvhzL-DqHkRo61koMaOZsOtDQkizM_ttbmPaY$> ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
