Zeiss Standard GFL
A little while back I purchased an old Zeiss Standard GFL stand for spares on eBay. The fine focus did not work, but this was of no consequence, as the bits I was after were in the substage assembly.
My father, Colin, who has a long standing interest in horology, thought that
it would be interesting to dismantle the fine focus to see how it worked.
He thought it would make a change to clocks and watches.
It wasn't long before he informed me that the fine focus had a stripped pinion.
At that point he thought it was a terminal problem and the patient would never
recover. Never one to be stopped by a challenge, however, and especially when
egged on by his other engineering friends, he decided to try and rebuild the
fine focus by cutting a new pinion. This he did, with complete success, and
then suggested that it would be a good idea to service my other, good, instrument.
It was fortunate that he did, because this one proved to be in the process
of failing in the same way. Both units
now have working fine focus mechanisms.
The damaged pinions
So, it seems that this particular component is a weak point in the Standard GFL.
I thought others might be interested in this tale, and also in my father's notes (PDF file, 2 MB), which although in pencil I think give a good description of his investigation and repairs.
Here is a link to the Zeiss GFL Manual
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