NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: The development of bubble sextants
From: Bill Morris
Date: 2009 Aug 24, 22:34 -0700
From: Bill Morris
Date: 2009 Aug 24, 22:34 -0700
Peter You wrote of your A12 sextant battery/bulb holder "I can pull the tube out about an inch or so, but no further. There are slits in the walls of the tube and I can see light from the slit on the opposite side. This means that I'm fortunate that there is no battery in the tube with the resultant corrosion. Do any of you have any special tricks for removing the tube? Heat/cold, etc.?" The A12 is notorious for corrosion and the two battery holders should not be stored in the instrument. You could try pushing it back in and removing the bubble unit and popping out the tinted skylight. Then employ a small child to apply some grease with its finger around the bulb holder, which is an aluminium casting attached to the thin-walled battery holder. Also squidge some grease through the slits from the inside while pulling and rotating. Then try pulling harder while pushing with your own finger. Forcefully rotating the thin casing with a wrench is likely to crush the rheostat housing or buckle the casing. I once had to break up the bulb holder casting and remove it in bits - a bit like old-fashioned obstetrics really - but the battery casing then came out easily. It wasn't too difficult to make a new bulb holder. Bill Morris Pukenui New Zealand --~--~---------~--~----~------------~-------~--~----~ NavList message boards: www.fer3.com/arc Or post by email to: NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
