Is anyone manufacturing custom slide rules?
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Now with solar declination and sine/cosine tables (in addition to height of eye correction, refraction, parallax, and upper/lower limb calendars)
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although this arrangement for the solar declination correction might be better, even though it makes low d changes less accurate.
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No, that is not actually useful as a slide rule.
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It remembers me the scrap of paper the stationery shops leave in the pencil aisle for customers, to test the pencils…
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The slide rule's refraction adjustment is now temperature compensated.
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Paper prototyping reveals that the inner and outer rings of the circular slide rule should have a larger difference in their diameters.
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that's not quite right for the declination compensator.
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Better, although now I'm worried that instead of computing the elevation of the sun, this slide rule will summon a demon instead
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That appears to correctly compute sin(declination)*sin(latitude) now
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Following up on the original question... Concise Products in Japan seems to still be producing circular slide rules https://www.sliderule.tokyo/products/detail.php?product_id=7
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The combined Latitude, Declination, LHA grid didn't work, so instead I've added the normal S/ST, and T/T1/T2 scales to allow computation of Hc and Z from the corrected sextant height.
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Printed and laminated a prototype of my solar slide rule on 350g A3 at the local print shop and it works fairly well! Correcting sextant height for index error, temperature, refraction, height of eye and lower limb is fast, as is computing latitude from the noon sight. Computing Hc and Z is a bit more involved (using additional scales on the reverse side)
