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Sunday, February 2, 2025

Spur Gears: Cheap Perhaps Scrap Source?

I am looking at the slow motion declination axis control.   This could be a worm gear or two spur gears.  The exact reduction ratio is not terribly important.   A slow motion control is used by an astronomer to make small changes, fractions of a degree at a time.   A worm gear is nice but worm gears with a .5" bore diameter are shockingly expensive.   A couple spur gears could do the job.  There are devices out there likely scrap that have slow gears galore in them.   Buy what sort of devices?

1 comment:

  1. It looks like you can get a 1:120 worm gear set with a 12mm bore on the gear (https://www.amazon.com/Brass-Worm-Teeth-0-4MM-Diameter/dp/B0B6VH2X71).

    12mm is a smidge over 15/32". It shouldn't be too hard to use a reamer (https://drillsandcutters.com/1-2-hss-straight-flute-hand-reamer/) to bring the hole out to 1/2". You are only enlarging the hole by about 0.028".

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