[RASMB] stuck screw ring

[Luitgard Nagel-Steger]

Hi Keith,

some time ago we have had the same problem. The thread was worn out and 
parts of it were broken, whether during the run or already during cell 
assembly, we don't know. Since nothing else helped, we finally decided 
to carefully cut off the part with the screw in our machine shop at the 
university. By this the housing was lost of course, but center piece, 
windows and window holders were saved.

Regards,
Luitgard

Connaghan, Keith D wrote:
> Hello,
>
> Recently a screw ring became stuck in a velocity housing used with our XL-A. This is the second time this has happened in the last few months. It appears that the screw ring becomes miss-threaded, one time after a 50,000rpm run, and a second during cell assembly prior to a run. In both instances the screw ring was threaded properly, gently tightened and loosened several times to further ensure proper threading, then at some point seizes such that the torque wrench and stand cannot loosen the cell assembly. (Our practice for assembling cells does not include Spin Coat due to the issues I have had with contamination of the windows and such.)
>
> That being said I have two questions. First, am I correct in thinking that the seizing of the screw ring is likely due to deformation of the cell housing? Second, we were able to use sturdier tools (compared to the torque wrench and stand) to separate the screw ring and housing in the first instance of this issue. However, no such luck in the second occurrence, does anyone have any suggestions for recovering at least the windows if not the windows and the centerpiece from the housing?
>
> Thank you in advance,
> Keith Connaghan
>
> Please note my email address is now keith.connaghan at ucdenver.edu<mailto:keith.connaghan at ucdenver.edu>
> -----------------------------------------------------------------------
> Keith D. Connaghan
> University of Colorado Denver
> Anschutz Med. Campus
> Dept. of Pharm. Sciences
> RC-2, Rm. 4450A, Mail Stop C238-P15
> (303)724-6119
>
>
>
>
>
>   
> ------------------------------------------------------------------------
>
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