JohnH
professor emeritus
Reged: 10/04/05
Posts: 734
Loc: vancouver near the wilds of B...
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Quote:
The 8 splines were overkill, I think you coulda stood on the thing after it was together. Placing them was not bad, once I got the first couple in. I held them in place temporarily with pieces of masking tape.
I wanted to make the skin from 3/32" or maybe even smaller but it was just not available anywhere in the Houston area in the quantities I needed. (Lotsa places had 1 or 2 pieces....) As for walnut veneer, have you priced that stuff lately?????
I haven't priced it lately, I just have friends who have friends.....etc etc. I belong to one of those groups of people into "wood porn". WE buy piles of materials and simply stockpile it. We go out and move it around every once and awhile or just to look at it.
Currently I am doing the same with pyrex blanks. Tragic, really.
As for walnut veneer, you are correct about the price. I do have an ace up my sleeve. A friend who moved to CA bought a piece of property with 25+ acres of walnut trees. He lives in one of those areas where the police will pull you over if you have wood like that in the back of your vehicle to see if you can account for it. He says if I come down there, I can have my choice of a tree.
Getting it home might be a problem as Hertz doesn't rent 5 tom flatdecks with cranes.
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Owen
professor emeritus
Reged: 06/21/07
Posts: 514
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Lets see if I can answer a few back 
A router with a circle cutter jig would have made very short work of the center circles (and the circle jigs are available to diy as easy as a very easy thing), which would have sped up the process...
The veneer need only have been used for the top and bottom sections of the OTA, the remainder would be stiff enough without the skin.
To save the expense of a dado blade all you needed to do was to slightly offset your jig - the kerf is around 3mm on a good blade (up to 6 on a monster carbide job), and that would have given you a wider stringer slot (infact if you performed the offest twice (so four passes), then you could get quite a wide groove ....
Have fun - this is an interesting build, and I'm looking forward to the developments.
Owen
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tim53
Pooh-Bah
Reged: 12/17/04
Posts: 1454
Loc: Highland Park, CA
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I like the jig you used for making the hexagons. I may try to rig up something like that next time I make a 9-sided tube with bulkheads. But these days I do that for refractors only.
I made my 8" f/6 Springfield's tube using bulkheads similar to the way you did it, though instead of the stringers, I routed grooves into the 1/4" plywood sides for them to live in. That was 1981. For years, I couldn't figure out why the planetary views I used to get with that primary were seldom up to snuff - I thought I might have selected a bad secondary mirror when I built the scope.
But when I had a similar problem with my 12.5" Cassegrain, I realized it was the bulkheads/baffles that were causing the poor definition. They were acting like stair steps for the tube currents to get into the light path, rather than hugging the walls of the tube.
The new (and final) tube for the Cass, I made with 1/4" Teak plywood with longitudinal corners made from poplar (of all woods!, but I selected samples that look pretty good with the teak), and I made the tube ID big enough (like 15") that tube currents (and glare) aren't a problem anymore.
-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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Pedestal
Post Laureate
Reged: 03/11/06
Posts: 3857
Loc: Smoggy Bottom, Baytown,Texas
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Here is a shot of the first (of many, I suspect) coats of "Sunrise Red". I put a reinforcing band around the bottom, where the mirror cell will mount. Boy, I hope I got all the holes in the right place!
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Hubert
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www.smoggybottom.org
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Pedestal
Post Laureate
Reged: 03/11/06
Posts: 3857
Loc: Smoggy Bottom, Baytown,Texas
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Here is a shot of the final (I think!) version of the mirror mount. Sent the mirror off to Spectrum for coating.
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Hubert
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www.smoggybottom.org
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Pedestal
Post Laureate
Reged: 03/11/06
Posts: 3857
Loc: Smoggy Bottom, Baytown,Texas
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Shot 1 of the mount cradle. The unpainted portions will be felt covered when the paint is done.
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Hubert
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www.smoggybottom.org
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Pedestal
Post Laureate
Reged: 03/11/06
Posts: 3857
Loc: Smoggy Bottom, Baytown,Texas
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The cradle will have a Vixen style rail. I think I'm going to use a "strap system" to hold the tube in the cradle. Still contemplating that one.
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Hubert
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www.smoggybottom.org
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polaraligned
sage
Reged: 12/26/08
Posts: 229
Loc: P. R. of New Jersey
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Beautiful work.
That red is the same color as the first telescope I built. It was a square wood tube. Somehow I wish I still had it.
Look forward to seeing the completed scope.
Scott
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Pedestal
Post Laureate
Reged: 03/11/06
Posts: 3857
Loc: Smoggy Bottom, Baytown,Texas
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Things are progressing. Got the mirror back from Spectrum. Here it is mounted in the cell.
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Hubert
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www.smoggybottom.org
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Pedestal
Post Laureate
Reged: 03/11/06
Posts: 3857
Loc: Smoggy Bottom, Baytown,Texas
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Making progress on the mount. Thought I had the counterweight situation figured out, until I priced lead shot. At $4 a pound, I'll figure something else out. For a sense of scale. The turned plate is 8" in dia, the dec shaft is 1".
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Hubert
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www.smoggybottom.org
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droid
rocketman
Reged: 08/29/04
Posts: 4040
Loc: ohio
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updates????????? I was holding my breathe waiting for the final pics, but I ran out of air.. 
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12 inch Truss Reflector "John"
102mm Celestron C102HD
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT
Remains of an 8 inch dob
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
11T 4.5 inch Tasco reflector Lunograsso?
60mm Telescope Club
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Don W
Postmaster
Reged: 05/19/03
Posts: 14621
Loc: Wisconsin, USA
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I think you'll find it here:
First Light
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Don Wyman
Obsession 18" f/4.5 #1166
W/Argo Navis DSC and Torus Primary
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Pedestal
Post Laureate
Reged: 03/11/06
Posts: 3857
Loc: Smoggy Bottom, Baytown,Texas
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Sorry-I forgot about this thread. I also decided it wasn't Rita anymore, it was the Red $$$ch 
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Hubert
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www.smoggybottom.org
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