NavList:

This is a cool sextant!  I would specify a couple of things to make it come out better:

• Select 100% fill for the 3-D printer so that it’s stiffer.
• Make sure you print the parts so that the “growth “ direction is perpendicular to the plane of the part as it lays flat.  Seems obvious, but sometimes vendors try to pack as many parts into a given build and so they print them vertically
• Print it white or grey so it doesn’t warp so much in the hot sun.  Black has always been a stupid color for plastic sextants, and the manufacturers should know better.
• You could specify SLA rather than a 3-D print.  Would give you a much finer detail, even though it wouldn’t be quite as rugged.

Re: Sextant with 3D printer
From: Frank Reed
Date: 2024 May 25, 21:19 -0700

Does anyone have any thoughts on this, any reply to this question, posted two days ago? Clearly, yes, Jan, I agree that the design of this "3D printed" sextant is similar to a Davis Mk3 plastic sextant. Like a Davis Mk3, it has a simple "sight tube" and a vernier scale for minutes of arc. Would there be any special concerns specific to 3D printing itself that would affect accuracy, either positive or negative? And I'll add a question: what would it cost to "print" one, if we sent the files to a service? And what would the additional components (mirrors? shades?) cost?

I'll say this, Jan, I want one, at least to experiment with, and I think the total price would be in the right range to compete with the intro-grade Davis sextant. I think I would want it in black plastic to make it look more "serious" :). And that is one interesting advantage of a 3D printed sextant. You can make small tailored, "bespoke" changes, additions, style choices that are simply impossible with an off-the-shelf item, like that Davis sextant.

Frank Reed

QUESTION FROM TWO DAYS AGO:
"Do you think this would work well enough for navigation? Would it be accurate to a minute of angle? I have a Davis Mark 3 sextant, and this printed one looks simiilar except that the frame is an open circle. Jan"