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Motors for ultima,meade lx and cg5 mounts??

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#1 whirlpoolm51

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Posted 28 October 2012 - 07:22 PM

Does anyone know exactly what type of motors are used in any of these mounts?? particularly the cg5-agt??

And also do they use 2 motors for tracking and one for slewing??? I would imagine using a lower rpm motor for tracking wouldnt be able to slew at a fast rate so do they have a seperate motor for slewing???

I would love some help on this please!!! hahahaha

what i really need to know is the type of motor ( DC servos??) and what gear ratio and rpms they have

thanks

#2 orlyandico

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Posted 28 October 2012 - 11:36 PM

the CG-5 ASGT, CGEM, and CGEM-DX use Igarashi motors.

They use an USDigital E4P encoder with 256ppr.

The gearbox has a really strange ratio, 47.976... (non-integral ratio)

This motor -
http://www.mpja.com/...or/productin...

has the exact same gear ratio as the CG-5/CGEM/CGEM-DX motors in fact some folks have transplanted the gearbox onto their CGEM motors (the actual motor above is much smaller than the CGEM motors).

#3 ccs_hello

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Posted 29 October 2012 - 07:28 AM

3 compound gears plus one on motor shaft and one on output shaft.

23/8 x 30/12 x 30/12 x 32/12 = 47.9166666667
When compare that figure with 47.9765625:1, it's 800:801 (strange, since 801 has a large prime "89" number in it).

89/32 x 23/4 x 3 = 47.9765625



Re: 2 different motors for different tracking or slewing speed (q from Whirlpoolm51)
No one does that. DC perm-mag has a wide speed range thus can do that. For hybrid stepper, it's the low gear-down mechanical gear box plus microstepping (electronic gear shift) does the wide dynamic range magic.


Clear Skies!

ccs_hello

#4 whirlpoolm51

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Posted 29 October 2012 - 04:29 PM

I know celestron uses a pittman amtek 19.1 vdc motor with a gear ratio of 60 5:1 so i was thinking of getting that but for sre not form celestron hahaha they want 350 for that motor with encoder and i can get it on ebay for 14.00 bucks and i alreayd have encoders hahaha

i have noticed they use very wierd ratios for thier eq mounts i dont get it!!


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