Some of the items I have made up for use with the Mk IX bubble Sextant.


Lamps More lamps

You can replace a filament "Bulb" with an LED, or, as I do, make up the brass parts as well.


Eye Guard, Original and some early attempts!         An original (left) with a typical production version for comparison



Home brew eye guard mounted on one of my Mk IXs


Battery adaptor. I use a penny for the contacts, not sure about the legalities but it works well.

How to check lamp socket polarity



A few of my sextants had scruffy mirrors and the thoughts were to re silver them or try replacing them with modern glass mirror. I located some mirror made of float glass, I could not get the same thickness so decided to go for thinner material. I cut the glass to size, ground the edges and because I noticed that the screws for the adjusters were removing the silver on the originals I coated the mirror backs with epoxy and placed some pads of stainless steel where the screws would make contact. The end result you see below.

I later realised that I could use as a hard backing, microscope slides. These I cut to size and glue onto the back of the mirror instead of the steel pads. These work well. Overall thickness is the same as the originals so fitting is not a problem. The same warning of course about the slight difference in thickness applies.

The center mirror is viewed from the front, it is flanked by two back views showing the epoxy and steel pads. The outer pair are the backs after a couple of coats of gold paint. Optically the mirrors seem no different to the originals, though theoretically, because of the different thickness of the glass, there will be a increasing error as one gets away from 0°. Once I adjusted the sextant I have done trials that seem, to all intents and purposes, to show the sextant works as well as when it had its original mirrors.


Above are shown a new Mk IX Prism cover. All the original ones I have seen are either a light orange or a deep red. This is an effect caused by age and they should be clear. I thought. WRONG! They should be a light orange colour. The clear ones I make I have found allow too much light in when pointing at the sun. I have had to add an extra light orange filter on top of the existing internal filter above the bubble chamber. If your bubble is difficult to see in daylight, but seems OK with the internal lamp at night,try removing the cover as a test. It may well have become too dark.

Most of my sextants have either lost some or all of their bubble chamber lamp filters. These are the small circular pieces to the right of the prism cover. I made mine out of modern plastic stage lighting filters. The originals are made of gelatine and will dissolve in water.

The bottom shot is of a replacement logging tablet I made. It is printed, not engraved and is more for appearance than utility.







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Things I get up to