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Help!.. need instructions to build a dob mount

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#1 morden8uk

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Posted 21 May 2009 - 06:51 AM

Hi All,

I'm trying to find some instructions on how to build a dob mount for 8" Orion Optics OTA. I'm currently using the 1200mm tube on a CG5, but would prefer a dob setup. The Orion Optics dob base costs £260!! - £over $300 which is criminal... surely I could build my own?.

Any help gladly received.

Thanks
Rob

#2 LLEEGE

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Posted 21 May 2009 - 07:38 AM

You may want to post this in the ATM forum.

#3 morden8uk

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Posted 21 May 2009 - 07:56 AM

Ahh, yes... thanks

#4 Doug76

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Posted 21 May 2009 - 08:11 AM

And they are very easy to build. When I bought my Dob Driver for my 12" Lightbridge, I didn't want to cut or alter my original mount, so I built a new one. Easy.

#5 John Carruthers

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Posted 21 May 2009 - 12:37 PM

Hi, first find the ballance point of your tube with all the finders/EPs etc attached, this will give you an idea how high to make the rocker box sides. Decide how big the side alt bearings will be, similar to the mirror diameter is a starting point, larger is good = lower rocker sides = less flex.
Now you can draw up a plan that allows the tube to reach both the zenith and slightly below horizontal (I found this out trying to watch the transit of Mercury as it rose from the sea).
The tube needs to be a snug fit between the sides or you get slop when you slew.
Fit textured hard laminate to the base and alt bearing surfaces.
Make a ground board, triangular for less weight or round so you can fit a setting circle later.
Aply teflon blocks so the overall loading is around 14 psi, ymmv.
Some glue etched teflon, I countersink and pin it.
Point and go.

#6 beachchairbill

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Posted 21 May 2009 - 08:43 PM

Hi,

Ask Dennis at Dobstuff.com and see if he can help you

BB






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