NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Observations with pocket sextant in the Baltic CROSS POST
From: hellos
Date: 2006 Jul 3, 12:07 -0500
Alex-
> I might try to design an eyepiece filter that is missing
> on my pocket sextant. I just wonder how much will it cost:-)
Is your eyepiece filter just an inset or filter glass? (Or something more
complex no doubt?) Can you point me to a URL where I can see a similar
instrument on the web?
(I cite as an evidence that C. Plath apparently
> went out of business because the PROCESS of frame manufacturing
> was too expensive).
Perhaps because they were manufacturing their new frame instead of sticking to
the old type similar to C&P? But given the slim demand for sextants, as
evidenced by the low prices in the used market, one might say it is not possible
to blame any one component for cost problems, rather, the entire concept of a
precision mechanical device, like a good mechanical chronometer, has been
obsoleted from the mass market by electronics. A sextant will be relegated to
the "Ferrari" market. That is, you splurge to buy one if you want one--but
that's "want" with no true practical need. There's actually a good market in "ne
plus ultre" goods of all kinds these days, not just luxury cars and $40,000
motorbikes.
"this is the ball bearing that connects the arm with the frame.
> The part you never see disassembled. I am not sure how to make it
> rotate exactly around the geometric axis of the frame. "
Perhaps if you were to visit the engineering department at your university? It
would seem that this is "just" a pivot point, ball bearings being simply a
reasonable way to make that happen. Maybe with modern materials they could be
eliminated.
And then, a gyro-stabilization device added (as some binoculars have now) or a
mirror-shaking stabilizer (as some digicams have now) both in the pursuit of
greater accuracy?
Seriously...it might interest an engineering class to take on the project of
redesigning a sextant for ultimate accuracy using modern materials and
techniques, as a project, with no further goal. Whether that could then be
transformed into something more....An interesting project anyway.
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to NavList@fer3.com
To , send email to NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---
From: hellos
Date: 2006 Jul 3, 12:07 -0500
Alex-
> I might try to design an eyepiece filter that is missing
> on my pocket sextant. I just wonder how much will it cost:-)
Is your eyepiece filter just an inset or filter glass? (Or something more
complex no doubt?) Can you point me to a URL where I can see a similar
instrument on the web?
(I cite as an evidence that C. Plath apparently
> went out of business because the PROCESS of frame manufacturing
> was too expensive).
Perhaps because they were manufacturing their new frame instead of sticking to
the old type similar to C&P? But given the slim demand for sextants, as
evidenced by the low prices in the used market, one might say it is not possible
to blame any one component for cost problems, rather, the entire concept of a
precision mechanical device, like a good mechanical chronometer, has been
obsoleted from the mass market by electronics. A sextant will be relegated to
the "Ferrari" market. That is, you splurge to buy one if you want one--but
that's "want" with no true practical need. There's actually a good market in "ne
plus ultre" goods of all kinds these days, not just luxury cars and $40,000
motorbikes.
"this is the ball bearing that connects the arm with the frame.
> The part you never see disassembled. I am not sure how to make it
> rotate exactly around the geometric axis of the frame. "
Perhaps if you were to visit the engineering department at your university? It
would seem that this is "just" a pivot point, ball bearings being simply a
reasonable way to make that happen. Maybe with modern materials they could be
eliminated.
And then, a gyro-stabilization device added (as some binoculars have now) or a
mirror-shaking stabilizer (as some digicams have now) both in the pursuit of
greater accuracy?
Seriously...it might interest an engineering class to take on the project of
redesigning a sextant for ultimate accuracy using modern materials and
techniques, as a project, with no further goal. Whether that could then be
transformed into something more....An interesting project anyway.
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to NavList@fer3.com
To , send email to NavList-@fer3.com
-~----------~----~----~----~------~----~------~--~---
