[RASMB] (no subject)

[Tom Laue]

Hi-
I would just add to Bo's response by saying you should make sure the 
screw ring and cell housing have a _thin_ coating of SpinCoat (sp??) grease.
Tom

Borries Demeler 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 appe=
>> ars that the screw ring becomes miss-threaded, one time after a 50,000rpm r=
>> un, and a second during cell assembly prior to a run. In both instances the=
>>  screw ring was threaded properly, gently tightened and loosened several ti=
>> mes 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 h=
>> ad 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 hous=
>> ing? Second, we were able to use sturdier tools (compared to the torque wre=
>> nch 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 window=
>> s and the centerpiece from the housing?
>>
>> Thank you in advance,
>> Keith Connaghan
>>     
>
> Is it possible that there was a small leak of a buffer, and some of the salts
> may have crystallized in the screw ring, making it sticky? In that case, maybe
> soaking overnight in a mild detergent could help, other than that I might try
> rapid heating/cooling cycles to break the deadlock through expansion and 
> contraction. Some torque wrenches have pins on which to set the cell housing,
> rather than the friction type. If you can find one of those, you may be able to 
> loosen it with the wrench.
>
> -b.
> _______________________________________________
> RASMB mailing list
> RASMB at rasmb.bbri.org
> http://rasmb.bbri.org/mailman/listinfo/rasmb
>
>   

-- 
Department of Biochemistry and Molecular Biology
University of New Hampshire
Durham, NH 03824-3544
Phone: 603-862-2459
FAX:   603-862-0031
E-mail: Tom.Laue at unh.edu
www.bitc.unh.edu
www.camis.unh.edu