Andrew May wrote in message
...
On 09/02/2012 14:34, Tim Downie wrote:
Andrew May wrote:

In the meantime dos anyone have any ideas about the purpose of the
spring. It can be seen at the bottom of the photograph on page six of
the document here if anyone is interested.

http://www.vad1.com/photo/dirty-scan...2000-cleaning/

Note: that this is the LS-2000 but the mechanism looks almost
identical.

I would guess it's there to remove any free play in the drive system.
That is, make sure that the there's no microscopic movement caused by
there being no loading on the gears at any point. (There's a proper
technical term for this but I'm darned if I can remember what it is at
the moment. Whiplash maybe)

Tim
That would make sense and would explain why it is not particularly
strong - just strong enough to keep the carriage on one edge of the
screw. I can't imagine it being strong enough to impede the carriage if
it is tensioned too much so I will look at something interfering with
its movement.

Andrew



I'm just wondering if something has gone wrong with microstepping. Course
back and forth movement and then at near focus dropping into microstepping
mode and not enough drive/wrong phasing / interaction with that spring