timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Well,not quite yet.
But I did get a start on my CHief project after spending a few weeks drawing up plans and agonizing over the details.
The lower end shown here is made from 5/8 baltic birch. 45 degree box joints - 240 of them - 
It was a fun trick getting it all glued up and clamped before the glue started to dry. 
The Fedex man dropped off my mirror yesterday While I was cutting the wood. Surplus Shed is gonna supply a 1/20th wave secondary. I've yet to order my lenses though.
The plywood was free! - a cabinet at work was being thrown out and I recycled it. I've got 10 coats of shellac on the box now. More to come in the days ahead - once I start a project things move along pretty quickly. Still a few details to be worked out on the fly.
Tim
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Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion 
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neo
professor emeritus
Reged: 02/12/08
Posts: 619
Loc: Iasi, Romania
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That is beautifull! How did you do those joints so perfect?
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Russian 15x50 binos
Home made 8" f/5 Newton on eq mount
Home made 70mm f/6 (Rodenstock Rotelar lens) Apo refractor
www.astronomy.ro
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kfrederick
professor emeritus
Reged: 02/01/08
Posts: 666
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great very nice /you will love the views/kevin frederick
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senske
sage
Reged: 01/10/09
Posts: 360
Loc: Spokane, WA
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Whoa! That's a fine looking box. Your telescope is going to be beautiful with craftsmanship like that. Nice job.
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Andrew
Orion SkyQuest XT10 Intelliscope with Orion 9x50 and Telrad Finders
Orion WorldView 10x50 Binoculars
Celestron NexStar 8 SE with GSO 8x50 and Red Dot Finders
Galileoscope
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perfessor
sage
Reged: 12/30/07
Posts: 499
Loc: Northern Illinois
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Can you share some of the optical specs? As in, primary size and focal length, details of the corrective lenses, etc.
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Tom
"Don't always know what I'm talkin about"
8" f/7
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rboe
Reged: 03/16/02
Posts: 45400
Loc: Phx, AZ
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The trick I hear for finger joints like that is to use white glue vs. the yellow stuff (which has this nice official name I can't spell  ).
Dang nice job so far. 
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Ron
NS11GPS
Pronto
16" dob
15X70 Obies
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Wes James
Post Laureate
Reged: 04/12/06
Posts: 3455
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Quote:
the yellow stuff (which has this nice official name I can't spell
... Aliphatic Resin... !
Beautiful finger joint work... the 45 degree angles throws a whole 'nother spin on them. Nice job!
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Gary Fuchs
scholastic sledgehammer
Reged: 05/22/06
Posts: 867
Loc: Easton, PA, USA
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Yes, very nice woodworking.
Gary
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Quote:
That is beautifull! How did you do those joints so perfect?
I made a rather simple 45 degree jig for the table saw and use a dado cutter. I can post a pic if anyones interested...
Quote:
Can you share some of the optical specs? As in, primary size and focal length, details of the corrective lenses, etc.
It's an 8" F/8 parabolic mirror - (from Iowa Scientific, by the way, if anybody has any info on thier mirrors I'd love to hear it) I'll be using a round 50mm 1/20th wave secondary from Surplus Shed and one each +/-500mm 50mm dia lenses. The perscription is posted on the Spiderless Yahoo group under files 8" F/8
Thanks All
Tim
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Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Quote:
The trick I hear for finger joints like that is to use white glue vs. the yellow stuff (which has this nice official name I can't spell ).
You mean E-l-m-e-r-s ??? 
Wish I would've know that sooner. Live and learn. Maybe next time...
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Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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tim53
Pooh-Bah
Reged: 12/17/04
Posts: 1454
Loc: Highland Park, CA
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I too love the box joinery!
I can't wait to see how the scope performs. Do you image with your scopes?
-tim
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"We`re just waiting looking skyward as the days come down.
Someone promised there`d be answers, if we stayed around."
-Orchestral Maneuvers in the Dark, "The Romance of the Telescope"
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Quote:
Do you image with your scopes?
-tim
I don't, but someday that may change. I've already got a Dob Driver for this scope on my mind - so maybe...cheaply - point and shoot stuff 
Tim
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Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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Wes James
Post Laureate
Reged: 04/12/06
Posts: 3455
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Quote:
You mean E-l-m-e-r-s ???
Actually, Titebond... Elmers was kind of a latecomer in the "yellow-stuff" game!
Your jig obviously was carefully set up and tweaked! The longer the length of the piece being cut for box joints, the more difficult it is to keep the spacing from developing a cumulative error. I know- I've wasted a lot of wood trying to set up box joint jigs for longer runs!
Wes
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RossSackett
professor emeritus
Reged: 08/17/07
Posts: 692
Loc: Memphis, TN
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I now use Titebond III for complex glueups because of its long open time.
Ross
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"A craftsman relies on science when the state of knowledge allows it, tradition and experience when it does not, and makes art whenever he can."
12 scopes from 4.25 to 18" and a 24" in progress. 12 ATM awards. Webpage: http://stardazed.com/ Some more scope pix at http://www.flickr.com/photos/8315630@N04/
Anagrams: Amateur astronomer = A mature moon-starer; Dobsonian maker = Debonair as monk
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Ed Jones
Pooh-Bah
Reged: 04/06/04
Posts: 1415
Loc: Sin-sin-atti
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Nice joinery Tim! I'm glad to see other folks making these. How tall is your box?
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Ed Jones
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davidpitre
Carpal Tunnel
Reged: 05/10/05
Posts: 1824
Loc: Central Texas
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Quote:
I made a rather simple 45 degree jig for the table saw and use a dado cutter. I can post a pic if anyones interested...
Please do.
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David
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orion63
super member
Reged: 12/10/07
Posts: 140
Loc: Lima, Peru
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Very nice workmanship! pretty impressive!
Ron's right, white glue is the way to go for this kind of joints.
Congrats!
Gonzalo
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rboe
Reged: 03/16/02
Posts: 45400
Loc: Phx, AZ
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They all make white and yellow glue, although Elmers is associated with the white glue - most folks would assume you ment white.
Wes: Shoot, now I can't even pronounce it! Thanks for piping in with the correct name.
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Ron
NS11GPS
Pronto
16" dob
15X70 Obies
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Quote:
Nice joinery Tim! I'm glad to see other folks making these. How tall is your box?
Ed
It's only 15 inches... I'm kinda flying by the seat of my pants here... I'm hoping the extra weight of the 5/8 ply will allow the shorter box... time will tell...
Quote:
They all make white and yellow glue, although Elmers is associated with the white glue - most folks would assume you ment white.
Sorry Ron
I really meant the whole Elmers thing as a joke - I have a strange sense of humor sometimes... 
But the tip on the white glue did sink into my sometimes thick skull - Thanks
Tim
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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rboe
Reged: 03/16/02
Posts: 45400
Loc: Phx, AZ
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Ah! Hard to catch dry humor on the net. Don't ask how I know. 
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Ron
NS11GPS
Pronto
16" dob
15X70 Obies
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Wes James
Post Laureate
Reged: 04/12/06
Posts: 3455
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... And I made a tongue-in-cheek post about how to pronounce "Titebond"... (It's not that difficult to pronounce- 'Tite-Bond'!) but deleted it out of fear it might have sounded disrespectful to you, Ron- something I'd never, EVER want to have happen! 
But dry humor is certainly fun... until it goes awry- or is misinterpreted! I myself am very fond of it... maybe too fond!
Wes
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Quote:
... And I made a tongue-in-cheek post about how to pronounce "Titebond"... (It's not that difficult to pronounce- 'Tite-Bond'!) but deleted it out of fear it might have sounded disrespectful to you, Ron- something I'd never, EVER want to have happen!
But dry humor is certainly fun... until it goes awry- or is misinterpreted! I myself am very fond of it... maybe too fond!
Wes
Thanks guys for laughing along and , of course, no disrespect was ever intended on my part - just having a little fun. Titebond is a little harder to spell than Elmers --- more letters, ya know? I can count too! 
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Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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Wes James
Post Laureate
Reged: 04/12/06
Posts: 3455
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Actually, I think Ron's and my comments were referring back to 'Aliphatic Resin'!
When he was commenting on not being able to pronounce it, I (tongue-in-cheek)switched it to 'Tite-Bond'!
Wes
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Soooo then...
With all this talk about glues and whatnot - would that qualify this as one of those "sticky" threads then? 
OK, OK, I PROMISE! - No more stupid jokes...
for now 
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Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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kfrederick
professor emeritus
Reged: 02/01/08
Posts: 666
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HI HOW are you going to have a ladder like ED does on his ? how are you mounting the corrector assembly ? looks great you will love the refractor like views unobstructed telescopes give / might be cool to build a newtonian uppercage / that way you could use it as a newtonian /then put the CHief together and see the difference/ i could do that with mine but it would be 13 ft high as a newtonian/
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tim53
Pooh-Bah
Reged: 12/17/04
Posts: 1454
Loc: Highland Park, CA
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I asked about imaging with one of these because I'm actually a little "worried" about the 'refractor-like' views introduced by the lens elements.
I prefer my refractors have "newtonian-like views" = "hyperapochromatic" 
-Tim.
--------------------
"We`re just waiting looking skyward as the days come down.
Someone promised there`d be answers, if we stayed around."
-Orchestral Maneuvers in the Dark, "The Romance of the Telescope"
Edited by tim53 (09/22/09 02:11 PM)
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TimD
scholastic sledgehammer
Reged: 02/16/05
Posts: 905
Loc: CA USA
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Beautiful wood work! Wish I had some of your talent over my way.
--------------------
Takahashi TSC 225
WO Megrez 102
Meade ETX 90, ETX 125
Meade LX90
Classic Orange tube C14, C90, C5+
Etc,Etc,Etc!!
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Wes James
Post Laureate
Reged: 04/12/06
Posts: 3455
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Quote:
Beautiful wood work! Wish I had some of your talent over my way.
Tim- Everybody starts somewhere... and it's never too late to start. People can learn this type of work. The biggest mistake one can make is thinking they're too old to learn- or it's too late to learn. Make that mistake and you're shortchanging yourself out of some of life's most enjoyable experiences. For instance- most people as adults say "I wish I had of learned (fill in the blank)... I'm too old now." WRONG! I, for instance, started playing guitar when I was 32... one of the best things I ever did. Started in astronomy at 58... same thing. Had a friend who- in her early 50's, always wished she'd taken up harp instead of piano. I told her- "So- what's keeping you from it?" I kept bugging her... she now has 2 harps- and enjoys playing them very much. (And is really quite good!)
Don't ever feel it's too late to start something. All it takes is a desire- and to follow through on it.
Wes
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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I agree, Wes
I don't think talent is so much inborn as it is aquired by doing. Most anything I've done, including those box joints is by first asking someone who's in the know and then trial and error. Add in a good deal of patience and you'll do most anything. 
The warm feeling of a job well done is the icing on the cake.
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
Edited by timo4352 (09/22/09 09:35 PM)
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rboe
Reged: 03/16/02
Posts: 45400
Loc: Phx, AZ
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It's a skill set that can be learned. When it comes to finger joints I'm not too sure - but it appears do-able. The jig is darn finicky, I'll say that much.
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Ron
NS11GPS
Pronto
16" dob
15X70 Obies
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kb4mxo
member
Reged: 07/17/06
Posts: 58
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Looks great and worked a bit on my chief. I am making mine from walnut and birds eye maple. I bought a house and fixing it up and that takes lots of time.
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Wes James
Post Laureate
Reged: 04/12/06
Posts: 3455
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Right, guys- skills are learned by doing, we aren't born with them. I read a lot of woodworking magazines for YEARS... seeing ideas, how to do things. Jigs are a wonderful asset, making finger joints, dovetail joints, etc. much easier. Jigs are wonderful for sharpening edged tools. We learn by reading, studying, seeing what others do- and how they do it. And then we practice these skills by doing. In almost any project anyone makes, they can look back and see something, somewhere they'd do different. That's how we learn and advance our skills. We just don't pop out into the world knowing how to do this. Any more than anyone is born "knowing" how to grind and test optics.
Wes
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kfrederick
professor emeritus
Reged: 02/01/08
Posts: 666
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is that the mirror box ? canot understand how your walnut base works
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Ed Jones
Pooh-Bah
Reged: 04/06/04
Posts: 1415
Loc: Sin-sin-atti
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Ooooh... walnut and maple, that will look sharp! What size are you making?
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Ed Jones
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kb4mxo
member
Reged: 07/17/06
Posts: 58
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Ed this will be for the 8" f7 optics.
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kb4mxo
member
Reged: 07/17/06
Posts: 58
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The mirror box is inside the base and bearings are not connected. The long maple pieces are for the beam.
Steve
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Quote:
I am making mine from walnut and birds eye maple.
Oh Yeah,
That will be a work of art! Keep at it. We need to see that thing assembled and varnished. 
Scope Update:
Hopefully I can get some pics up tommorrow - I got the cell just about finished... Then it's onto the ladder...
Tim
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Hey guys
A little update on the CHief...
The mirror cell is just about done - got some pics...
1.
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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2.Gotta get the right bolts for it yet.
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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3. Looking at the bottom of the box. The pics doesn't really make it clear, but the cell is mounted at an angle in there. Lots of room for air circulation. 
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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4. Looking down in from the top. The offset isn't as obvious in this pic - shows better in the last one...
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Oh Yeah -
Forgot about the box joint jig...
1.
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
Edited by timo4352 (09/24/09 07:11 PM)
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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2. that's the tricky part - getting the stop set at the exact width of the groove...
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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kfrederick
professor emeritus
Reged: 02/01/08
Posts: 666
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very nice work / like to come out for the first light party kevin
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PitchHitter
member
Reged: 09/23/09
Posts: 23
Loc: Southern Sierras
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Missing is the quote asking about specs.
Well I see this question asked more than once. It looks like something I designed on paper about 20 years ago or more so I am going to take a swing. I inherited a 16.25" that was f:7.5. I had to refigure it but what a performer on just bare glass. Best view of Orion's Nebula that I have ever seen. But I had to borrow a step ladder to comfortably view through it as my eight foot ladder left little to hold on to at zenith. I never would call and in my view the current name is wrong because Herschel was all about NOT having a secondary!
Here is what I came up with but never finished because the coating lab burned down while they had my mirror. It took seven years to get it back.
16.25" f:7.5 intercepted at f:6 with a 4" flat (or f:15 sperical) center of axis 3" out from in coming path of light. I was going to make two low power corrector lenses from bottoms of Mayonaise jars, one negative and one positive of about 1 diopter and 3" diameter. I had a 2" 60 mm eyepiece and this would give me an unobstructed field of 2" with an 8mm exit pupil. The two correctors would be half way between the eyepiece and secondary as convenient and touching on one side with an airspace wedge between them. Because of the possiblity of reflections I was going to Magnesium Flouride coat the correctors in a salt bath.
Hope this helps...
Edited by PitchHitter (09/25/09 08:43 PM)
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kfrederick
professor emeritus
Reged: 02/01/08
Posts: 666
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making corrector lenses from the bottom of mayonaise jars??
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Hey Gang
Lots of work this weekend on my CHief project...
I got the ladder built, focuser mounted, made the top end of the ladder from a piece of 1/4" plexiglass I had laying around - just gotta tap the threads in it for my secondary adjustment screws. Got the ladder mounted to the box. I have to get some good hardware for mounting everthing - I've just been using whatever I had laying around for now...
Next will be the making the lens holders and finishing up my secondary holder. A little more tinkering with the cell too.
Getting closer... 
Tired Tim
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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plexiglass secondary mount plate
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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ladder mounted
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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focuser mounting
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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baffle
Someday I gotta get a new camera... sorry the pics are lousy
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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Ed Jones
Pooh-Bah
Reged: 04/06/04
Posts: 1415
Loc: Sin-sin-atti
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Looks great Tim!
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Ed Jones
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Hey Ed -
What size hole do you put in your lens holders for a 2 inch lens?
I'm thinking 1-3/4" but wanted to consult with the expert...
Thanks
Tim
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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Ed Jones
Pooh-Bah
Reged: 04/06/04
Posts: 1415
Loc: Sin-sin-atti
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Tim,
I would make it 1.90 inches basically a little smaller than the lens diameter to cover as wide a field as possible but allow some centering movement.
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Ed Jones
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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OK Ed, a couple more questions, if you please...
Here's a pic taken through the focuser - with the secondary installed and showing my primary cell (no primary or corrector lenses installed yet). (I used a round secondary so it appears oval when it's mounted on the angle.)
Does everthing look about right to you? About what you'd see in one of your CHiefs? The blue underneath is just a blue board I have it sitting on.
I'm also thinking that seeing how my cell is so open that I'd like to install a baffle maybe an inch (more or less) above the primary. Shouldn't interfere with airflow and I'll need to block that stray light from the bottom...
The lens holders will also cut down the wide open view I have here, I would imagine - maybe wont see so much of the ladder? I'm guessing I'll have to black out parts of the ladder anyways...
What do you think?
Thanks again
Tim
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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Ed Jones
Pooh-Bah
Reged: 04/06/04
Posts: 1415
Loc: Sin-sin-atti
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Yes I'd say it looks reasonable, you can see all of the primary. The lens holders act as a stop so only light passing through them gets to the eyepiece. After you install the lens holders I would paint anything that you can see black and the stop in front of the primary should help. Good control of stray light in the Chief is one of it's advantages.
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Ed Jones
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Thanks Ed - your help is much appreciated.
At this rate I may have the ota done by next weekend. 
Then I'll have to figure out my base pronto so I can use it. I'm gonna look into really large diameter alt bearings 15-20 inches maybe - to work with my shorter box. Gotta check out my balance point once it's all together and go from there...
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
|
timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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I've got the ota pretty much all assembled now. Collimation went OK - fairly easy to set it up so it looks close.
I had a rather uneventful first light tonight... 
No base yet - just aiming the ota at the moon - it seems I'm gonna need an extension piece, but that's not the worst of it - - the best I got was a rather blurry (streaky looking?) image of the moon. I didn't try adjusting the lenses as it's pretty hard when I'm hand holding the ota. That'll have to wait for now. I've got to go back over my drawings and check all the measurements and angles again. Ed tells me the most critical distance is from the focus point to the convex lens, so I'll start over from there. Still gotta make a little angle adjustment gauge - today I just lined them up off of my drawing but I guess that isn't good enough...
The lens boards were really tricky to get right - it's really intricate work and took a looooong time to get them together. 
I've got a few pics to post showing the lens boards and adjustments and stuff...
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
|
timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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The view down the focuser with the lens holders installed
Notice that lack of obstruction?  
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
|
timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Looking up the ladder - after the lens boards were installed
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Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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kfrederick
professor emeritus
Reged: 02/01/08
Posts: 666
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very nice i like the lens adjusting wire .Should not have any dew problem on that secondary up in that box.
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kfrederick
professor emeritus
Reged: 02/01/08
Posts: 666
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the problem i had was when i moved the lens group .it changed the tilt .i think my next one i will have the rod held in a way ,so you could slide the lens group and it would not change the tilt adjutment.great job you will love it.
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Wes James
Post Laureate
Reged: 04/12/06
Posts: 3455
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Tim-
Very nice looking worksmanship!
Wes
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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What a relief!
Turns out the "streaky image" was a HUGE blur??? 
A MAJOR adjustment to the lenses as a group brought that into focus - literaly. Testing on a phone pole looks pretty darn good for now - fine details are evident - ie. spiderwebs and stampings on hardware, etc. The best I can do for now. I was getting worried there... but things are looking up... 
Time for a little nap - I've been up since 5am messing with this. 
Tim
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Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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kfrederick
professor emeritus
Reged: 02/01/08
Posts: 666
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great you will love it . So you made a spiderless telescope[EDs group is called siderless ]and first light you are looking at spiderwebs .
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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In my quest to be frugal I'm gonna try a different bearing material for my mount. I bought a recessed lighting diffuser sheet made by Plaskolite. The cracked ice version.
http://www.plaskolite.com/products/flat_sheet/lighting_panels/lighting_duralens.cfm
The front side is a little too bumpy and sharp, but the backside feels pretty good against a block of teflon. A 2x4 panel is enough to do both the alt and az bearings. The thing only cost $9 so I'm not out much if it doesn't work well. Don't have it together yet, but I'll report on the result...
Tim
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Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
|
timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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The CHief is all together - not pretty yet - but together.
The base works pretty good. I put an adjustable spring on the side to balance it out. Some pics...
Tim
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Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
|
timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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fuzzy pic of the spring setup
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Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
|
timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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And what I'm hoping is good alignment
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Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
|
David L
sage
Reged: 11/12/07
Posts: 278
Loc: Lee County Iowa
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I see your base is a fork mount. When I first started doing fork mounts on my dobs, I used shelf brackets, and who knows, I might even go back to using them. A fork mount allows you to mess around the zenith more easily. Dave
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16" Lightbridge, 10" F4.5 Homemade with Orion optics, 6" F6.5 Antares 1529 refractor, 6" F8 Homemade with Orion optics, 100mm F5.6 finderscope, 22X100 Oberwerk binocs, 8.5X44 Swift Audubon binocs, Orion Atlas mount, equatorial platform, various tripods and altaz mounts
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Ed Jones
Pooh-Bah
Reged: 04/06/04
Posts: 1415
Loc: Sin-sin-atti
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Pretty cool Tim, any trouble getting it balanced?
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Ed Jones
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AV in CMH
sage
Reged: 11/07/05
Posts: 462
Loc: Columbus Ohio
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Great looking scope.
Anthony
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Thanks for the kind words...
Ed - nope the balancing was pretty easy - the only thing being was because the weight is shifted to the one side because of the 45 arrangement - and I put a spring and a turnbuckle on the opposite side- and that seems to work pretty good.
I used shelf brackets too - had them lying around and it just made things quicker and easier.
Tim
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Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
|
timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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FINALLY got a few minutes of clear sky to try out the CHief.
All my daytime fussing must have paid off and I got it adjusted in pretty easily on a REAL star tonight. The rings look good and round in and out of focus.
I still don't have the BFL verified but I must be close because things look pretty good.
Still the seeing was pretty lousy so it may need a little more tweaking when things shape up around here. When I first looked at Jupiter two of the moons were so close I thought the alignment was off showing two moons instead of one... Went inside and checked on the comp. and there was two right next to each other - no problems
High power was not really an option tonight but with a 25mm eyepiece,for 65X, things looked dandy---- At 125X - not so good... We'll see what happens on a better night...
I didn't have to do any adjusting of the lens centering for color correction...good news for those of you who are worried about color with the F/8 - I see NO false color at all. Maybe some will show up at higher powers? - I don't know
I got a couple more pics before it got dark - hope I haven't overloaded you guys with pics...
Tim
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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I added two baffles in the box - one just above the mirror and another below on the cell. There's no stray light getting to the eyepiece from there. And still lots of breathing room.
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
|
timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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from the rear...
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Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
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ottovonrotton
member
Reged: 01/01/09
Posts: 65
Loc: Where is Port Perry?
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Brilliant, but which glue tastes better white or yellow
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Go Modern, Go Gas, Go Bang!
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Ed Jones
Pooh-Bah
Reged: 04/06/04
Posts: 1415
Loc: Sin-sin-atti
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Nice work Tim, is it ready to varnish?
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Ed Jones
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Yes, I'm about ready to do the finishing. Maybe I'll play with it for a week or two first. Might send the mirror in for a new coating while I'm finishing.
Tell me Ed, what harm does it do to NOT have the BFL correct? What abberation would show? Or is it just impossible to adjust in?
With this setup the way it is I can measure the primary to first lens distance easier than the second lens to focus. Unless I build the LED deal you mentioned...
As it is I think I'm pretty close but I'm just guessing.
Tim
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
|
Wes James
Post Laureate
Reged: 04/12/06
Posts: 3455
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Tim-
Looks really nice! What are the rails made out of that support the upper cage? It appears to be fairly small wood stringers, which doesn't look like it'd have enough torsional ridigity to avoid twisting- have you noticed any problems with it flexing? Or does it just look like it might?
Wes
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kfrederick
professor emeritus
Reged: 02/01/08
Posts: 666
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Tim the distance from the last lens to focus can be adjusted by moving the primary up and down.. if you have enough adjustment turn all three bolts one turn and see if it is better. i can move my flat to do this adjustment on the 20 inch//kevin
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Ed Jones
Pooh-Bah
Reged: 04/06/04
Posts: 1415
Loc: Sin-sin-atti
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Tim,
Actually the tolerance on this isn't as bad as I thought. When I increased the BFL +.5 inch from nominal the Strehl drops by .060 and when I decreased the BFL by -.5 the Strehl dropped .017. Better to be short than long but both cases are diffraction limited. So then if your mirror radius actually measures 128 inches then you could use a tape measure to measure the top front edge of the mirror to the bottom rear edge of the first lens which should read 51 & 13/16 inches. If your radius is off a little from this just scale this number proportionally.
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Ed Jones
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Thanks Ed 
And once the moon comes back - then I can try the scotch tape to focus trick too.
Tim
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
|
timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Quote:
Tim,
Actually the tolerance on this isn't as bad as I thought. When I increased the BFL +.5 inch from nominal the Strehl drops by .060 and when I decreased the BFL by -.5 the Strehl dropped .017. Better to be short than long but both cases are diffraction limited.
Ed
So if I'm reading it right I really have at least one inch of room to adjust and I still wouldn't notice any difference at the eyepiece? That just made building this scope a lot easier than we thought then. Do you think?
Tim
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Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
|
Ed Jones
Pooh-Bah
Reged: 04/06/04
Posts: 1415
Loc: Sin-sin-atti
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|
Yes it's a very tolerant design if it can be off +/- .5 inches. It's always best to get it as good as you can though.
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Ed Jones
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timo4352
super member
Reged: 04/16/07
Posts: 160
Loc: Northeast Ohio
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Me, being the perfectionist that I am, will have to get it just right to be happy. It's good to know there's some breathing room though.
BTW thanks for putting my scope up on the spiderless homepage. It made me feel real good that you thought enough of my scope to do so.
Tim
--------------------
Orion 3.6CA Reflector
and 2 homebrew scopes --
8" Hubble Bubble ballscope
8" F/8 CHief - nearing completion
|
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