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#1 Don Allen

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Posted 16 July 2014 - 06:37 PM

I had a Gemini 2 on my mount and decided to go with DSC's and the digital drive system given my back yard. With the DDS installed I cannot get the mount to move at any speed close to what I had with the Gemini, even at 12x. I am using same battery source, completely charged.

Did the motor change make that much difference or I am missing something?

#2 JMW

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Posted 16 July 2014 - 06:56 PM

I believe the digital drive system is designed for tracking and minor positioning. I think the idea is you keep the clutches a little loose and push the scope to the object and let the drive do the tracking. Basically you have a push-to gem with DSC and tracking. Humans can slew faster and quieter than motors anyway.

#3 Don Allen

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Posted 16 July 2014 - 07:15 PM

I was thinking that is what I had; but coming from the G11 with a Gemini, I was not sure.

Thanks.

#4 MikeCatfin

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Posted 17 July 2014 - 09:44 AM

Yes, the G11 with the DDS uses stepper motors as opposed to the servo motors on the Gemini, so hence it doesn't really slew - it is meant mostly for tracking or positioning an object once in the approximate area. No need to loosen the clutches - once set up, just push the mount to where your object is, center it and let it track. Works quite well.

#5 JMW

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Posted 17 July 2014 - 10:51 AM

Mike, I don't own the G11 but am actively looking for a DDS with encoder setup that is available at a good used price. So once you have the balance right you set the clutches to allow pushing in RA or DEC and they still hold well enough to track when you aren't pushing on the scope. Is that how it works?

I have a DM6 on a Losmandy extension on my Planet tripod. I would use the G11 for planetary public outreach so I don't have to nudge the scope for the public.

#6 MikeCatfin

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Posted 17 July 2014 - 02:02 PM

Hi Jeff, yes that is exactly how it works. Prior to switching over to Gemini, my G11 had the digital drive, encoders and an Argo Navis unit and it worked great. The reason I switched over was to be able to do some sort of remote imaging.
So, basically put your scope on it, loosen the clutches to balance, then tighten them up again and your good to go. Once the encoders are on and connected to digital setting circles such as the Argo Navis or Sky Commander, all you do is just put in either your object or ra/dec coordinates and push to the object. Once there the tracking picks up.

#7 Don Allen

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Posted 17 July 2014 - 09:11 PM

Thanks Mike.

#8 gnowellsct

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Posted 17 July 2014 - 11:13 PM

Mike, I don't own the G11 but am actively looking for a DDS with encoder setup that is available at a good used price. So once you have the balance right you set the clutches to allow pushing in RA or DEC and they still hold well enough to track when you aren't pushing on the scope. Is that how it works?

I have a DM6 on a Losmandy extension on my Planet tripod. I would use the G11 for planetary public outreach so I don't have to nudge the scope for the public.


YOu have to have *some* clutch tension but not a lot. I basically set the clutches so that if I bump the scope it doesn't go haywire.

YOu set the controller to 16x for visual use.

Please note that as you get closer to the north pole the RA button becomes progressively more worthless in making adjustments. That's not a fault of the mount, it's geometry.

Greg N

#9 gnowellsct

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Posted 17 July 2014 - 11:17 PM

I was thinking that is what I had; but coming from the G11 with a Gemini, I was not sure.

Thanks.


The virtue of the stepper motors is that they are totally un-finicky. No lag errors. Stepper motors either work or they don't. If they can't do the job they stop. They don't burn out. You can work at 100F to -20F without needing to reset the worm gear. Set it and forget it...

Greg N

#10 Don Allen

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Posted 19 July 2014 - 04:54 PM

I put the DSC's on the mount. I hope this is what most people see when they are installed correctly.

Attached Files



#11 Startraffic

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Posted 20 July 2014 - 09:32 AM

Don,
Those are completely different than mine. Mine are the older style & look like aluminum boxes ~2"x1.5"x1.5" with an RJ45 connector on the side. They are fitted into flat spots milled into each of the axis's. I'll try to fins some pics of them to post.


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#12 Startraffic

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Posted 27 July 2014 - 09:29 PM

Don,
I found an older pic of the encoders.
http://www.astrobin.com/25362/
http://www.astrobin.com/25364/



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