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Updated Schaefer Mount

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#1 Lynnblac

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Posted 25 March 2011 - 12:50 PM

I have updated my Schaefer GEM by installing a Losmandy Digital Drive. Schaefer mounts cane with synchronous motors only. No slewing speeds, just sidereal speed. Now I have 3 guide speeds and 3 slew speeds. I also added a dec gear replacing the original tangent arm. The mount now has a dovetail clamp to attach the ota. Here are some shots of the new mount.

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#2 Lynnblac

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Posted 25 March 2011 - 12:52 PM

more

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#3 Lynnblac

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Posted 25 March 2011 - 12:53 PM

and

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#4 skybsd

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Posted 25 March 2011 - 01:58 PM

Looks fantastic! :waytogo:

Are you all ready to go? Anything else to get done before you can get it out under some night skies?

Regards,

skybsd

#5 Lynnblac

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Posted 25 March 2011 - 08:09 PM

I have observed a couple time with the new drive, works great. This my astro photo set up so now I need to set up the autoguider.

#6 skybsd

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Posted 26 March 2011 - 05:22 AM

Hi,
Thanks for that..,

Its great knowing that there are those of us still around that can take an instrument like this and update and restore it to new capabilities..,

And, it does look so awesome!

Presumably you're aiming for a portable set up?

Regards,

skybsd

#7 SPACEMAN

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Posted 26 March 2011 - 06:41 AM

That's a nice looking upgrade. What is the PE error?

#8 Jeff Morgan

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Posted 26 March 2011 - 12:49 PM

Great looking mount Lynn! I have a refurbished AT-9 and have often thought about doing this. For now I have a power inverter for remote operation. Of course that is no answer for fast slewing, a capability I would love to have.

How about a few more details? What size mount is yours, the -7? How do you determine what size motors are required?

#9 Lynnblac

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Posted 26 March 2011 - 03:40 PM

Jeff and all,

This is a 6" Schaefer, one of the smallest, and yes it is a portable rig. Bill Schaefer used Byers gears which have a reputation for low PE. A friend uses a 9" Schaefer to carry his 12" astrograph, guided with an ST-4, and it works just fine without even PEC correction. He designed and built his own stepper drives for his mount.
This a stock G-11 Digital Drive 492, these come up for sale on Astromart as G-11 and G-8 owners upgrade to Gemini Goto drives. The G-8 has a 8 min. worm cycle, the G-11 is 4 min. My mount has an 8 min. cycle (180 teeth worm wheel) so the G-11 (4 min.) drive required a 2 to 1 reduction to get the needed 8 min. cycle. I added a dec. gear to make the mount more compact, got rid of the large saddle plate and replaced with a dovetail clamp. But this mod could be done using the original saddle and tangent arm drive. My dec gear was salvaged from an old Meade SCT fork drive, that also has a 180 tooth worm wheel. I suppose a Gemini Goto could be added to my mount. BTW when G-8/G-11 owners upgrade to Gemini Goto they have to replace everything, drive box, handcontoller, motors, cables, everything, so you pickup a complete system this way, cool. Lynn

#10 Lynnblac

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Posted 26 March 2011 - 04:05 PM

Skybsd

Saving an old Cave Newtonian was one of my most satisfying ATM project I have completed. It was literally melting in the owners backyard! Now it is in regular use for visible solar system observing. The mount had to be beaten apart during the restore, but now it is a fine telescope. Like I said, satisfying. Lynn

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