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Finished my 8 Inch Travel Scope

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#1 Tim C

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Posted 09 February 2013 - 05:44 PM

Hi Folks,

I recently completed an 8 inch f6 travel scope that I started sketching out last fall. It’s modeled after the Sumerian Optics scopes that I looked at online and also another CN member “what?” posted his 10 inch version made from an Orion back in October and I really loved his version.

I wanted this scope for my annual trips out West and also to take down to the beach. It won’t get used a ton so I just went with GSO optics from Agena. It packs up to a box that is carry on size (measures 9x14x17.5). That is if I’m brave enough to try carrying it on a plane (fear of getting gate checked will probably stop me). I’ll probably just check it and carry on the mirror box when traveling on a plane.

Got 11 pics that I’m posting – here is the first:

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#2 Tim C

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Posted 09 February 2013 - 05:44 PM

2. Here is a close up of the mirror box. The lightweight mirror and small dimensions required meant that I needed to use pulleys to balance (like the Sumerian). The bearings would have needed to be too big. I’m using 3/16” shock cord on both sides. I found I needed two pulleys to get enough range of stretch. Takes some fiddling to figure out how to make it balance and sit still throughout the whole range of motion but wasn’t too hard. The cord stop at the end makes it easily adjustable. It works very well and is pretty insensitive to eyepiece changes.

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#3 Tim C

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Posted 09 February 2013 - 05:45 PM

3. Here is the rear-end shot. I found that stability is best using 4 levelers (they just slide on and off of the box and have felt so it won’t damage the finish). I tried 3 points at first but 4 worked better. Mirror cell is just made from plywood and mirror is attached using silicone (Stellafane design).

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#4 Tim C

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Posted 09 February 2013 - 05:45 PM

4. Here is a close-up of the UTA attachment. Cut from aluminum angle using a table saw. The poles are from Texas Towers using a 7/8” for the lower half and ¾” for the upper. They are joined using tube insert nuts. I got different sizes so they would nest inside one another (there is a picture later).

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#5 Tim C

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Posted 09 February 2013 - 05:46 PM

5. Here is the secondary holder. Curved vane spider using a ruler (thanks Mr. Seronik). I did add collimation thumb screws.

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#6 Tim C

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Posted 09 February 2013 - 05:46 PM

6. Here is the scope with the shroud (sourced from Heather at Teeter Telescopes).

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#7 Tim C

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Posted 09 February 2013 - 05:46 PM

7. One neat thing about the GSO mirror set is that it came with a plastic cap that makes a great protective cover. It sits on the edge of the bevel of the mirror and doesn’t touch the face of the mirror. I added Velcro straps. Best to leave this on while assembling so you don’t drop any hardware on the mirror.

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#8 Tim C

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Posted 09 February 2013 - 05:49 PM

8. Here is the mirror box with its wooden cover on (attached with thumbscrews). This is what I’ll probably carry on for flights. Might even add a handle so it carries like small briefcase. The mirror box measures 12.75” x 12.75”. You can see the nested truss poles in the background.

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#9 Tim C

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Posted 09 February 2013 - 05:50 PM

9. Here is how it fits in the box. I wrap a towel around the loose stuff which holds it firm when the box is closed.

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#10 Tim C

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Posted 09 February 2013 - 05:50 PM

10. Another shot showing the assembled box (weighs about 25lbs with everything inside). I used Formica crystal finish for the laminate.

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#11 Tim C

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Posted 09 February 2013 - 05:50 PM

11. Last pic – this is the side of the box where the Teflon pads attach.

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#12 Pinbout

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Posted 09 February 2013 - 05:51 PM

very nice job. :bow:

how big did you make the alt bearings?

#13 Tim C

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Posted 09 February 2013 - 05:53 PM

Oh, I forgot to say how the optics perform. They seem to be pretty good. I've had it out twice in the yard. Stars are pin point across the entire field and it should be great for low to medium power viewing which is what I wanted it for. Higher power on Jupiter is OK - I'm spoiled probably by the higher contrast in my 8" f8 dob. Central obstruction in this scope is fairly large at 23%.

#14 Tim C

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Posted 09 February 2013 - 05:55 PM

Thanks Danny. They are 24 inch in diameter. I think I would have needed about 35 inches to balance without using the cord.

very nice job. :bow:

how big did you make the alt bearings?



#15 starman345

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Posted 09 February 2013 - 06:43 PM

Beautiful job Tim, I really like the stain, also that ruler spider

#16 zjc26138

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Posted 09 February 2013 - 08:56 PM

Great job Tim! What beautiful scope.

#17 Tim C

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Posted 09 February 2013 - 09:01 PM

thanks guys. Brian - that finish is "Expresso" (General Finishes). My wife talked me into using a darker stain and I'm happy she did.

#18 Pinbout

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Posted 09 February 2013 - 09:11 PM

tell me more about your feet.

#19 Tim C

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Posted 09 February 2013 - 09:34 PM

Pretty straightforward really. Just 3 pieces of 1/2 inch plywood glued together to form a "U". The "U" slides onto the bottom edge of the box and is 1/2" wide with the felt. I have the levelers screwed onto the plywood U's. Hopefully that makes sense.

By they way Danny, I think you're the one that pointed me to the Formica crystal finish for the laminate (reading some of your old posts) so thanks for that. I've used it on two scopes now and it works as good as the ebony star and it's much cheaper and available at the big box stores.

Tim

tell me more about your feet.



#20 mattyfatz

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Posted 09 February 2013 - 09:48 PM

Magnificent!
That is a great looking scope. The box is awesome too.
I would definatley carry that on an airplane.. Those dimensions are well within the carry on limits.. Get yourself one of These puppies to make your life easy when cruising around the airport. I wouldn't worry too much about the primates at the TSA. they won't know what a telescope is but they can't stop you from bringing it on. As soon as they start to say something ask for a supervisor.. Helps to have the website up on your phone too as you go through.
It's better to keep that beauty in your possession the whole time you travel.

#21 David Pavlich

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Posted 09 February 2013 - 09:54 PM

Oh yea...that's a home run!!

David

#22 Scott in NC

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Posted 09 February 2013 - 10:02 PM

Very nice, Tim! That scope is a real work of art. :applause:

#23 bremms

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Posted 09 February 2013 - 11:26 PM

Nice scope. Wanted to do something similar with my 8" F6. I travel a good bit and that is very compact and handsome.

#24 Benson

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Posted 10 February 2013 - 12:40 AM

Extraordinary workmanship. I am impressed.

#25 StarStuff1

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Posted 10 February 2013 - 03:47 AM

Clever design and excellent craftsmanship! :bow:






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