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ctcables
professor emeritus


Reged: 11/14/06

Loc: Oregon
The Making of my 20" telescope for a Carl Z mirror
      #5755364 - 03/25/13 01:18 AM

So not sure how all this is going to turn out but we will see.

The Project: Make a telescope to hold a F4.5 20.03" by 1" thick 22lbs quartz mirror being made by Carl Z with a Lockwood 3.5" Flat.

Photos of work done to this point, will add as I get more done.

To help with weight I have used carbon fiber over balsa. Very light and very strong.

For the rings I am using a composit honeycomb board also very strong and very light. The stuf is used in aircraft.



[URL=http://s245.photobucket.com/user/ORduner/media/20130322_043449.jpg.html][IMG]


I hope when done the telescope with mirror will be under 40lbs

Edited by ctcables (03/26/13 12:43 AM)


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Daud
sage


Reged: 08/05/06

Loc: AZ, Scottsdale
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: ctcables]
      #5755393 - 03/25/13 01:49 AM

Whoa, he is back, after 4 years...when can I get a 24" quartz blank form you, Chris ?

Edited by Daud (03/25/13 01:49 AM)


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ctcables
professor emeritus


Reged: 11/14/06

Loc: Oregon
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: Daud]
      #5755417 - 03/25/13 02:19 AM

So changing this post to a list of what people guess for the weight.
Marc 45.7LBS
kfrederick 51.0LBS
ausastronomer 47.4LBS


So NO prize as per CN, sorry wish I could give one out.

Edited by ctcables (03/28/13 12:58 AM)


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mark cowan
Vendor (Veritas Optics)
*****

Reged: 06/03/05

Loc: salem, OR
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: ctcables]
      #5756422 - 03/25/13 03:27 PM

Quote:

I hope when done the telescope with mirror will be under 40lbs




That'd be amazing. I'm guessing 45.7, can you start a contest??

Best,
Mark


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ctcables
professor emeritus


Reged: 11/14/06

Loc: Oregon
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: mark cowan]
      #5757094 - 03/25/13 09:55 PM

Sounds like a good plan Mark, what do you think the prize shold be? Nice Quartz mirror blank? Say in the range of 6 to 12 inches? I will see what I have on hand, so start putting your guesses for the final weight.

To inclued telescope, mirror, foucser, finder, secondary,and eyepice. Anyother ideas would be great. Will post photos as I move along with this project.


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mark cowan
Vendor (Veritas Optics)
*****

Reged: 06/03/05

Loc: salem, OR
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: ctcables]
      #5757230 - 03/25/13 11:26 PM

I'm including the weight of the SIPS Paracorr but no EP...

Best,
Mark


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ctcables
professor emeritus


Reged: 11/14/06

Loc: Oregon
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: mark cowan]
      #5757303 - 03/26/13 12:34 AM

Not sure on the paracorr but will be using a fethertouch light which is only .8 lbs. should I include the base with controler? may do a platform for tracking but not sure yet. Going to talk with Dan Gray about what system will work best with what I want to do. Anyway sounds like a fun give away, nice thing to do for all the people that have helped out over the years. So get the weight right and win a quartz mirror blank. Will post size tomarow. Plan on completing the telescope before OSP.

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GeneT
Ely Kid
*****

Reged: 11/07/08

Loc: South Texas
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: ctcables]
      #5757328 - 03/26/13 12:57 AM

Very interesting project. Keep us updated on how things are progressing.

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tezster
scholastic sledgehammer
*****

Reged: 07/14/09

Loc: Missisauga, Canada
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: GeneT]
      #5757634 - 03/26/13 07:49 AM

Wow... that'll be an super light-weight scope for a 20" - my 10" DobStuff weighs just a shade under 40 pounds, and I already consider that fairly light.

This one will be fun to follow


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ctcables
professor emeritus


Reged: 11/14/06

Loc: Oregon
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: tezster]
      #5757645 - 03/26/13 08:06 AM

should this post be moved to ATM, Optics and DIY Forum? It is a reflector but might be better suited in the DIY area? if so how do I move it or should I just restart it? Anyway Lots to do yet but taking my time.

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kfrederick
Carpal Tunnel
*****

Reged: 02/01/08

Re: The Making of my 20" telescope for a Carl Z mirror new [Re: tezster]
      #5757657 - 03/26/13 08:15 AM

Making things very strong and very light is not very easy . Chris Thanks for the glass I have gotten . I know your telescope will be very nice .A fast 20 is the perfect size . I say 51 lbs .[If no helium is used in the tubes] Ha Ha

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ausastronomerModerator
Carpal Tunnel
*****

Reged: 06/30/03

Loc: Kiama NSW (Australia)
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: kfrederick]
      #5758682 - 03/26/13 05:13 PM

Hi Chris,

I am guessing at 21.5kg which is 47.4lbs.

This is the exact weight of my 10"/F5.3 truss dob, which is designed to be rock solid and steady. It will be a tremendous effort to get a 20" down to that weight.

PS If I win I will pay the freight, after Carl Z turns it into another gem

Cheers,
John B


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Starman1
Vendor (EyepiecesEtc.com)
*****

Reged: 06/24/03

Loc: Los Angeles
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: mark cowan]
      #5758747 - 03/26/13 05:44 PM

Quote:

I'm including the weight of the SIPS Paracorr but no EP...

Best,
Mark



The SIPS does have the advantage of never having to guess about perfect coma correction, but there are advantages to the "slide-in" Paracorr:
--it parfocalizes all your eyepieces. If the truss poles are cut correctly, you may be able to achieve focus very close to the in-most position of the focuser. This has the advantage of minimizing the secondary-to-focal plane distance and reducing sag in the focuser due to the weight of heavy eyepieces. With the SIPS, your eyepieces will focus over a range.
--it is normally already removed when setting up, so collimation doesn't require removal, unlike the SIPS (some people do remove the SIPS lens when tearing down, but I don't think all do).
--it will never insert beyond the end of the focuser drawtube
--it is threaded for filters on the bottom end, standardizing filter diameter and making it possible to exchange eyepieces without changing the filter from eyepiece to eyepiece
--it can be removed easily and used in another scope so it can easily be shared with others or if you have more than one scope set up.
--Depending on your focuser cost, it might be cheaper in combination with the focuser than the SIPS focuser + Paracorr ensemble.
--it makes correction of an already existent scope easier than changing the focuser.

Obviously, this f/4.5 scope will need a coma corrector. If you build the scope assuming a 31 Nagler and Paracorr in the focuser, overall balance will be pretty good.


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ctcables
professor emeritus


Reged: 11/14/06

Loc: Oregon
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: Starman1]
      #5759307 - 03/26/13 10:21 PM

I have posted a photo of the 6" mirror blank that will be given to the winner. Also I have started a list of guesses and will keep it updated in the 3rd post, this should help people save time. So if you want to see what others have put for weight just go to the first page 3rd post. Good luck.

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ctcables
professor emeritus


Reged: 11/14/06

Loc: Oregon
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: ctcables]
      #5759341 - 03/26/13 10:44 PM

So just got informed that Cloudy Nights needs to give the OK for me to give the blank away. should be ok but if things change very sorry. Will post when I find out.

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ctcables
professor emeritus


Reged: 11/14/06

Loc: Oregon
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: ctcables]
      #5761612 - 03/28/13 12:48 AM

Good news I am allowed to give the 6" blank away to the winner or person that gets near the weight of the telescope.
My rules: Items to be included in weight of telescope!
1: Focuser
2: secondairy, wire spider and secondary cell.
3: 20 inch quartz mirror 1" thick
4: 18pt mirror cell with side support
5: main rotation bearing.
Not included in weight is drive system and telescope platform/stand.

6:deadline to get your guess in is April 30
7: winner of the free 6" quartz mirror blank will be contacted when the telescope is completed I hope before Oregon Star Party. Good luck



Edited by ctcables (03/31/13 12:33 AM)


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ctcables
professor emeritus


Reged: 11/14/06

Loc: Oregon
Re: The Making of my 20" telescope for a Carl Z mirror *DELETED* new [Re: ctcables]
      #5761616 - 03/28/13 12:55 AM

Post deleted by ctcables

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ausastronomerModerator
Carpal Tunnel
*****

Reged: 06/30/03

Loc: Kiama NSW (Australia)
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: ctcables]
      #5763109 - 03/28/13 08:17 PM

Hi all,

This thread and giveaway by Chris is all good to go.

Please guess away as you wish.


We have untagged Chris as a vendor as he has wound his business down. There was never any question of Chris's generous intent with this giveaway, but as a tagged vendor it was against the rules and they have to be applied consistently for all vendors.

Good luck in the Giveaway.

Cheers,


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ctcables
professor emeritus


Reged: 11/14/06

Loc: Oregon
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: ausastronomer]
      #5763186 - 03/28/13 09:02 PM

Hay thank you so much for doing this for me. Back on for the 6 inches blank give away. get the weight right and win this very nice 6" mirror blank including shipping with in the USA.







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ctcables
professor emeritus


Reged: 11/14/06

Loc: Oregon
Re: The Making of my 20" telescope for a Carl Z mirror new [Re: ctcables]
      #5763324 - 03/28/13 10:27 PM

Very cool delivery to day, just recived my 3.5" Lockwood quartz secondary mirror, wahooo. Around 1lbs.







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