I'm here for more videos on the welding glass and beam splitter- I'm looking forward to making the original and playing with it some, but I'll quickly be looking for more variations to experiment with.
You could look at 2 glass beam splitters rather than Yrvind's original 3 glass. These do not work with plane glass because of attenuation but they do with beam splitters. I have not experimented with them but would be interested.
Thanks for this video you mention using welding glass but in the video you show the construction using only clear microscope slides. Should welding glass be cut to microscope slide dimensions and then affixed as the third pane?
I've been meaning to make a video specifically about the use of welding glass but haven't got round to it yet. I briefly mention it at the end of my video on Bris sextants theory and there is a picture of my arrangement using welding glass as an additional filter at timestamp 9:10 in that video. Yrvind did what you suggest and cut a piece of welding glass to size to act as one of the three glasses in the sextant, the outer one. You could also use it as the inner one but you can't use it as the middle one without altering the relative intensities of the different reflections. The problem with that is that it makes it very hard or impossible to see the horizon through the sextant and it also means you can see fewer reflections because the lower ones become too dim. So I mount it as a fourth glass on the observer's side of the sextant and only covering the top part so that it only filters out the real image of the sun and the first three virtual images. I use a much wider welding glass than the sextant is so that it filters the sun for both eyes; the sextant's only being viewed through one eye. This makes the sextant significantly larger than Yrvind's original but it gives you more reflections, and it also allows you to see the horizon more easily through the sextant.
I don't see why it shouldn't work, but it might be difficult to assemble. It's much harder to get two joints to set correctly simultaneously than it is to get just one. And if you use a wedge, you'd have to get the wedge in position and the second glass at the same time if you glued both joints together. If you didn't and started by gluing the wedge onto the bottom of one glass and then gluing another glass onto the wedge, it would be really hard to keep the second side of the wedge free from epoxy. If any epoxy got onto it, it would alter the angle. I found even for microscope slides with two glued together at one end, often epoxy gets on the outside of one or other of the slides to interfere with a subsequent joint. I imagine it would work well for a sophisticated manufacturing processes, but for making it by hand would probably be difficult.
Thank you for sharing your information and video.
Thanks for making this instructional video Patrick!
Thanks for the comment.
I'm here for more videos on the welding glass and beam splitter- I'm looking forward to making the original and playing with it some, but I'll quickly be looking for more variations to experiment with.
You could look at 2 glass beam splitters rather than Yrvind's original 3 glass. These do not work with plane glass because of attenuation but they do with beam splitters. I have not experimented with them but would be interested.
Fine job! Try Thousand Oaks solar filter...Tank's
Thanks for this video you mention using welding glass but in the video you show the construction using only clear microscope slides. Should welding glass be cut to microscope slide dimensions and then affixed as the third pane?
I've been meaning to make a video specifically about the use of welding glass but haven't got round to it yet. I briefly mention it at the end of my video on Bris sextants theory and there is a picture of my arrangement using welding glass as an additional filter at timestamp 9:10 in that video.
Yrvind did what you suggest and cut a piece of welding glass to size to act as one of the three glasses in the sextant, the outer one. You could also use it as the inner one but you can't use it as the middle one without altering the relative intensities of the different reflections. The problem with that is that it makes it very hard or impossible to see the horizon through the sextant and it also means you can see fewer reflections because the lower ones become too dim. So I mount it as a fourth glass on the observer's side of the sextant and only covering the top part so that it only filters out the real image of the sun and the first three virtual images.
I use a much wider welding glass than the sextant is so that it filters the sun for both eyes; the sextant's only being viewed through one eye. This makes the sextant significantly larger than Yrvind's original but it gives you more reflections, and it also allows you to see the horizon more easily through the sextant.
Thank you for this reply! I do hope you'll have time to make that other video: this and the theory video are both excellent
I have taken up celestial navigation whilst recovering from a medical problem.
Do you have a spare Bris Sextant you can send me?
3d print the wedges to correct angles then glue. Would that work?
I don't see why it shouldn't work, but it might be difficult to assemble. It's much harder to get two joints to set correctly simultaneously than it is to get just one. And if you use a wedge, you'd have to get the wedge in position and the second glass at the same time if you glued both joints together. If you didn't and started by gluing the wedge onto the bottom of one glass and then gluing another glass onto the wedge, it would be really hard to keep the second side of the wedge free from epoxy. If any epoxy got onto it, it would alter the angle. I found even for microscope slides with two glued together at one end, often epoxy gets on the outside of one or other of the slides to interfere with a subsequent joint. I imagine it would work well for a sophisticated manufacturing processes, but for making it by hand would probably be difficult.