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Author Topic: Custom Ratio Support  (Read 5230 times)

photo444

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Custom Ratio Support
« on: November 08, 2014, 04:32:28 »

Hi Tom,

I have ordered one unit today but I want to make sure it will work with my EQ mount.  RA has 144T worm and a gear set of 42/18 so total ration is 336, and DEC has 300 total.  Any suggestions please?

Thanks,
Paul
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TCWORLD

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Re: Custom Ratio Support
« Reply #1 on: November 08, 2014, 17:28:10 »

Hi Paul,

You didn't say what step angle your motors are.

If they are 7.5 Degree, then it would be possible using 1/32 microstepping, but you would only get 2arcsec resolution.

If they are 1.8 Degree, then you would be able to get up to 0.5arcsec resolution.
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Tom Carpenter (AstroEQ)

photo444

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Re: Custom Ratio Support
« Reply #2 on: November 10, 2014, 16:31:46 »

Thank you for the reply, Tom.
I am thinking of using 200 steps (1.8 deg)or 400 steps (0.9 deg) motors.
Is it worthwhile to make RA/DEC ratio to be 1.0?  This can be done by selecting right gear ratios for RA (144) and DEC (90).
 
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TCWORLD

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Re: Custom Ratio Support
« Reply #3 on: November 10, 2014, 18:06:31 »

The ratios don't need to match.
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Tom Carpenter (AstroEQ)

photo444

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Re: Custom Ratio Support
« Reply #4 on: November 10, 2014, 20:30:51 »

Hi Tom,

Thanks for your suggestions.  I may settle with the gear ratios above and 0.5 or 0.25 arc-second resolution, and may play with electronics until Christmas. Arduino Mega board and several stepper drivers I have will keep me busy for a while.

Thanks,
paul

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photo444

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Re: Custom Ratio Support
« Reply #5 on: December 31, 2014, 21:59:08 »

Receiving an AstroEQ a few days ago, now I have rigged up with my mount.
RA:144 Gear:4 Microstep:32 1.8deg
DEC:90 Gear:6 Mocrostep:32 1.8deg
The ET8 mount is slewing very faithfully, just waiting for clear nights for further trial.


« Last Edit: December 31, 2014, 23:47:03 by photo444 »
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