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Motor Focus

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#1 foste1cc

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Posted 20 January 2013 - 11:35 AM

Hey everyone. I was just wondering if any of you know of cheap motor focuser that will fit and work well with a Celestron SCT Nexstar 8SE. I see that celestron makes an electronic motor focuser made specially for this telescope but costs $180. I see that orion and a couple others make much cheaper focusers. Do any of you know of cheaper focusers that will work for me?? I can't stand the shaking/vibrations anymore!! thanks in advance guys!

#2 herrointment

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Posted 20 January 2013 - 01:00 PM

emediadesigns.com/focuser/

#3 foste1cc

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Posted 20 January 2013 - 01:33 PM

This looks like a great idea and fun project. Thanks a bunch for the reply and help! the video looks like it works just as good as the expensive ones

#4 StarDusty

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Posted 20 January 2013 - 02:43 PM

Nice and simple. Great idea.

#5 herrointment

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Posted 20 January 2013 - 08:10 PM

I built one and I would be lost without it.

Actually I've built 3 and can say that the mini-servo has the ideal speed range once you get the pulleys sized correctly. Higher torque models cause unnecessary headaches.

#6 Gene7

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Posted 20 January 2013 - 08:26 PM

I would put it on a real telescope though, not a SCT. Gene

#7 herrointment

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Posted 20 January 2013 - 09:01 PM

I actually use mine to control the temperature of my heating pad.....no more bending!

#8 WarmWeatherGuy

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Posted 21 January 2013 - 11:00 AM

You might be interested in this YouTube video How to Focus a Wobbly Telescope. A Bahtinov mask may be all you need.

#9 Geo.

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Posted 21 January 2013 - 10:30 PM

Love the Shack when I can't wait, but check out the Electronic Goldmine.com for parts at a fraction of the Shack's prices. http://www.goldmine-elec.com/

I think a gear head motor will be easier to get good results with as there's less a tendency to cog at the higher speeds you can run it.

This Goldmine Mini Gearhead Motor Sayama 12SM-AT3 looks to be the same one used in Meade's ETX focusers. Item G16300.

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#10 akawaka

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Posted 23 January 2013 - 09:29 PM

I'm working on something like Brian Sumpters design, I'll post some details once I'm done. I couldn't find a micro continuous servo and didn't want to mod my own so I got a slightly bigger size which means I'll probably have to rig up some kind of mounting plate to mount the servo upside down. For the control hardware I'm using an arduino micro because I want to be able to control this over USB also.






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