Mount gear ratio calculator

[Astrofriend]

Have you ever had thoughts to build your own motor driven mount? Then you need to know how to get the gear ratios you need. You also need to know what angular resolution your motor works with, what does one step from your motor correspond to in arc seconds.

I have made a Mount Gear Ratios calculator on my homepage. It's new for today and there can be some mathematical erros in the calculation so double check everything before you buy any expensive parts!

Here it is:

http://www.astrofriend.eu/astronomy/astronomy-calculations/mount-gearbox-ratio/mount-gearbox-ratio.html

Let me know if you find anything wrong with it.

/Lars

[Saturnine]

Thanks for the work you do Lars, that is a very handy calculating tool. Have made a few mounts with varying degrees of success and have a partly formulated plan to make an skytracker type mount for widefield astrophotography using geared 12V motor and worm gears. May make working out the ratios easier than my calculation methods.

[Astrofriend]

Hi Jeff,
Thanks, have you find any good hardware driver and software Ascom compatible for DC motors with angle sensor?

/Lars

[Saturnine]

Hi Lars
Almost forgetting to reply, no I haven't got as far as looking at Ascom compatible software, mainly just working on the mechanical aspects of a design. I will have to teach myself how to program stepper motors, are a few guys in my club who are electronically proficient that I could ask for guidance.
Just working on getting the drive ratios correct for the worm drive , then maybe fine tune with an PWM unit / 12V DC motor combo.

[Astrofriend]

Hi Jeff,
Maybe this kit could be interesting:
https://www.astroeq.co.uk/tutorials.php

I have not tried it myself, but a friend bought it to his DIY mount and what I know it working as it should, but for sure a lot of problem to solve during his project.

/Lars