NavList:

   

Reply

Bill,

It is nice. Can you show the additional mirror mounting
from behind, so that the adjusment mechanism could be seen?
Or it is only adjustable in a workshop?
Actually two ajustments are needed, as for the ordinary sextant.

1. Both mirrors must be perpendicular to the plane of the sextant arc,
and
2. Index error. The rays from the front and from behind must
be parallel when the drum is at 0.

The second adjustment is in fact not necessary, one only has to
determine this index error, as we do with normal sextants.
And your collimator arrangement does this. But for the first
adjustment one needs to be able to regulate the angle between
the second additional mirror and the plane of the arc.

I am also curious about any sea trials you can make.

Alex.

On Thu, 5 Apr 2012, Bill Morris wrote:

>
> In case anyone is still interested in the subject after a diet of SNO-T, 
station pointers, and lubricants, I have adapted on old sextant to make a dip 
meter, for fun rather than for serious use. I give an account of it on my web 
site at:
>
> http://sextantbook.com/category/navigational-miscellany-other-navigational-instruments-and-devices/
>
> Bill Morris
> Pukenui
> New Zealand
> ----------------------------------------------------------------
> NavList message boards and member settings: www.fer3.com/NavList
> Members may optionally receive posts by email.
> To cancel email delivery, send a message to NoMail[at]fer3.com
> ----------------------------------------------------------------
>
>
>
>
> : http://fer3.com/arc/m2.aspx?i=118727
>
>
>

   

Reply