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<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=232264917-12042013>Arthur, FYI my XL-I drive (with ~30
billion revolutions) seems definitely to have started leaking drive oil
over the last year or so. Thus the turbomolecular pumps
will apparently not fix all the oil issues. Fortunately this oil mostly
accumulates on the circuit boards below the removable bottom plate, and at least
when running at 20-25 C isn't a big problem for the optics. Note too
that my XL-A with similar revs still leaks no noticeable drive oil, so
this issue does vary from one drive to another.</SPAN></FONT></DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=232264917-12042013></SPAN></FONT> </DIV>
<DIV dir=ltr align=left><FONT color=#0000ff size=2 face=Arial><SPAN
class=232264917-12042013>John</SPAN></FONT></DIV>
<DIV lang=en-us class=OutlookMessageHeader dir=ltr align=left>
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<FONT size=2 face=Tahoma><B>From:</B> rasmb-bounces@list.rasmb.org
[mailto:rasmb-bounces@list.rasmb.org] <B>On Behalf Of </B>Arthur
Rowe<BR><B>Sent:</B> Friday, April 12, 2013 10:43 AM<BR><B>To:</B> Laue,
Thomas<BR><B>Cc:</B> RASMB<BR><B>Subject:</B> Re: [RASMB] turbo-molecular pumps
in Beckman XLA XLI<BR></FONT><BR></DIV>
<DIV></DIV><FONT class=Apple-style-span color=#950f0b>Hi all</FONT>
<DIV><FONT class=Apple-style-span color=#950f0b><BR></FONT></DIV>
<DIV><FONT class=Apple-style-span color=#950f0b>I warmly endorse the praise for
the work put in by Walter (2005 onwards) in both getting a turbo pump
working in an XLI/A instruments - and in getting Beckman to take this idea
seriously.</FONT></DIV>
<DIV><FONT class=Apple-style-span color=#950f0b><BR></FONT></DIV>
<DIV><FONT class=Apple-style-span color=#950f0b>I recall that I had little
success in the latter area when I tried in 2004. As I posted on RASMB (April 7th
2004):</FONT></DIV>
<DIV><FONT class=Apple-style-span color=#950f0b><BR></FONT></DIV>
<DIV><SPAN class=Apple-style-span style="FONT-FAMILY: Times"><PRE style="WHITE-SPACE: pre-wrap"><FONT class=Apple-style-span color=#02208c>"The problem with oil in the XL-I/A is a notorious and intractable one.
Having a turbo pump instead of that horrible 'straight through, unvalved' DP
system sounds very easy to do, and I have long contemplated doing it. After
all, you can get compatible flanges, I am sure. And as a long-time electron
microscopist and builder of ancillary equipment I just shudder at the
crudity of AUC vacuum systems.
However - such discussions as I have had with Beckman people suggest that
this approach (using a turbo) would help but not really solve the oil
problem, which is at least partially due to oil from the drive shaft of the
motor, not just to oil from blowback from the DP."</FONT></PRE></SPAN></DIV>
<DIV><FONT class=Apple-style-span color=#950f0b>I wonder if the story which
Beckman gave me in 2004 about leakage of oil vapour from the drive shaft of the
motor was other than a 'smoke screen' for inaction? Or is there really oil
leaking in that location?</FONT></DIV>
<DIV><FONT class=Apple-style-span color=#950f0b><BR></FONT></DIV>
<DIV><FONT class=Apple-style-span color=#950f0b>Arthur</FONT></DIV>
<DIV><FONT class=Apple-style-span color=#950f0b><BR></FONT></DIV>
<DIV><FONT class=Apple-style-span color=#950f0b>Professor Arthur J
Rowe<BR>NCMH/Food Sciences<BR>University of Nottingham<BR>Sutton
Bonington<BR>Leics LE12 5RD UK<BR><BR>Tel: +44 115 9516156<BR><A
href="mailto:arthur.rowe@nottingham.ac.uk">arthur.rowe@nottingham.ac.uk</A></FONT></DIV>
<DIV><BR>
<DIV>
<DIV>On 12 Apr 2013, at 16:52, Laue, Thomas wrote:</DIV><BR
class=Apple-interchange-newline>
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<DIV
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma; COLOR: rgb(0,0,0); DIRECTION: ltr">Here,
here!<BR>Tom<BR>
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style="FONT-SIZE: 16px; FONT-FAMILY: 'Times New Roman'; COLOR: rgb(0,0,0)">
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<DIV id=divRpF949963 style="DIRECTION: ltr"><FONT color=#000000 size=2
face=Tahoma><B>From:</B><SPAN class=Apple-converted-space> </SPAN><A
href="mailto:rasmb-bounces@list.rasmb.org">rasmb-bounces@list.rasmb.org</A><SPAN
class=Apple-converted-space> </SPAN>[rasmb-bounces@list.rasmb.org] on
behalf of David Hayes [drdavidbhayes@yahoo.com]<BR><B>Sent:</B><SPAN
class=Apple-converted-space> </SPAN>Friday, April 12, 2013 11:44
AM<BR><B>To:</B><SPAN
class=Apple-converted-space> </SPAN>RASMB<BR><B>Subject:</B><SPAN
class=Apple-converted-space> </SPAN>[RASMB] turbo-molecular pumps in
Beckman XLA XLI<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV>
<DIV
style="FONT-SIZE: 12pt; FONT-FAMILY: arial, helvetica, sans-serif; COLOR: rgb(0,0,0); BACKGROUND-COLOR: rgb(255,255,255)">
<DIV>Hi all,</DIV>
<DIV><BR></DIV>
<DIV
style="FONT-SIZE: 16px; FONT-FAMILY: arial, helvetica, sans-serif; COLOR: rgb(0,0,0); FONT-STYLE: normal; BACKGROUND-COLOR: transparent">Just
wanted to write a public thank-you note to Walter Stafford for pioneering
hardware work to get Beckman to put in turbomolecular pumps in their
analytical ultracentrifuges. We recently had an install of a new XLA and
found out that even the XLA's come with turbo pumps standard. This made
me wonder if Beckman ever wrote a thankyou letter to Walter for pioneering
this hardware improvement, which thought led me to write a thank you letter to
Walter for this and also for all the years managing and contributing to the
RASMB list for biophysics scientists.</DIV>
<DIV
style="FONT-SIZE: 16px; FONT-FAMILY: arial, helvetica, sans-serif; COLOR: rgb(0,0,0); FONT-STYLE: normal; BACKGROUND-COLOR: transparent"><BR></DIV>
<DIV
style="FONT-SIZE: 16px; FONT-FAMILY: arial, helvetica, sans-serif; COLOR: rgb(0,0,0); FONT-STYLE: normal; BACKGROUND-COLOR: transparent">David
Hayes</DIV></DIV></DIV></DIV></DIV>_______________________________________________<BR>RASMB
mailing list<BR><A
href="mailto:RASMB@list.rasmb.org">RASMB@list.rasmb.org</A><BR><A
href="http://list.rasmb.org/listinfo.cgi/rasmb-rasmb.org">http://list.rasmb.org/listinfo.cgi/rasmb-rasmb.org</A><BR></DIV></SPAN></BLOCKQUOTE></DIV><BR>
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