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droid
rocketman
Reged: 08/29/04
Posts: 4252
Loc: ohio
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Ok I posted this over in the reflector forum, but got no reply.So...............
how do you make a shroud for a truss tube scope???
Id assume that you need a wedge shape generally ,as the bottem of the trusses are larger than the top.
Any help would be appreciated.
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12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
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csa/montana
Den Mother
Reged: 05/14/05
Posts: 43849
Loc: montana
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Andy, which truss do you have? Depending on which scope; you might have to sew supports or plastic rings in it, to keep it from falling into the lightpath. I have the Astrozap, which has the rings in it. It came with cord, to tighten it at the top & bottom, but it didn't do a great job; so I easily replaced the cords with bungi cord. This works really great!
The photo was before replacing the cord with bungi, you can see it wasn't held tightly.
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Carol
AstroTech 16" Dob (Thanks ASTRONOMICS!)
Vixen 80MF/AstroTech Voyager
Masuyama's 7.5, 15, 25W, 35mm,
Pentaxes; 5XW, 7XL, 10XW.
14mm Meade 4000 UWA
TV Panoptics; 22, 35
DreamCatcher Dobservatory
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Shawn H
Post Laureate
Reged: 05/16/07
Posts: 3961
Loc: Southern France 43°56'N-4°50'E
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Well I guess its simple enough! I ordered mine from Heather at Teeters Telescopes. All she needed was the diameter of my OTA, the diameter of the rocker box, and the length of my trusses! She then sew'd a black nylon stretch material to those specifications! 
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18" David Lukehurst truss Dobson with Sky Commander flash 4 DSC's & Moonlite CR2 focuser & Astrocrumb filter slide
Orion xt10i fully flocked with Telrad on 4" risers & Feather Touch focuser & huge Boston Red Sox decal
The original Orion StarBlast & 15x70 Celestron Skymaster binos & Ethos & Naglers & Dobs oh my!
Orion Ultrablock narrowband filter & Astronomik OIII line filter
Tele Vue 2x Barlow & Antares 1.6x (2") Barlow
CATSEYE collimation tools, TeleGizmos Dob covers
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droid
rocketman
Reged: 08/29/04
Posts: 4252
Loc: ohio
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ok heres my problem I dont have 80.00 to there abouts to toss at it, so I will buy the material from the fabris store and make it myself, Im thinking, how long does the bottem have to be to close snugly around the truss, how long does the top have to be to close snugly around the trusses, and how high does it need to be.
While all three seem easy enough , I know the resulting layout will actually have a curved edge on the bottem and top but reversed.
I know this from making paper shrouds for a couple of my amatuer rockets.In that case I downloaded the plans and transfered them.
In this case I will have no such luxury.
So I wondered if anyone else had done theyre own, could they/or would they pass on information.
Or am I over thinking it???
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12 inch Truss Reflector "John"
102mm Celestron C102HD " Carl "
Tasco 7TE5 60mm Classic
Tasco 9TE5 60mm Classic
Celestron Ultima 2000 SCT "Wilma"
Celestron Comet catcher(orange tube)
1960 Edscorp Space Conquerer 6inch f/8
10x50 Bushnell Binoculars.
60mm Telescope Club
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Shawn H
Post Laureate
Reged: 05/16/07
Posts: 3961
Loc: Southern France 43°56'N-4°50'E
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Andy
Maybe you are over thinking it! Or maybe its not as simple as it seems to me! I'm no tailor!  I thought just cutting the material in funnel fashion, with your outside UTA diameter length on top, then the longer of your trusses, with a few inches added to sew in the elastic, then the outside diameter length of your rocker box at the bottom, then either sew it closed, or Ive seen some with velcro! Now I am just trying to think logically! Ive never made one myself! Soo your probley better off asking on the ATM forum! 
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18" David Lukehurst truss Dobson with Sky Commander flash 4 DSC's & Moonlite CR2 focuser & Astrocrumb filter slide
Orion xt10i fully flocked with Telrad on 4" risers & Feather Touch focuser & huge Boston Red Sox decal
The original Orion StarBlast & 15x70 Celestron Skymaster binos & Ethos & Naglers & Dobs oh my!
Orion Ultrablock narrowband filter & Astronomik OIII line filter
Tele Vue 2x Barlow & Antares 1.6x (2") Barlow
CATSEYE collimation tools, TeleGizmos Dob covers
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Skylook123
Postmaster
Reged: 04/30/05
Posts: 5245
Loc: Tucson, AZ
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The ones I've used are constant diameter Lycra. Although there is a taper to the truss, the upper cage assembly widens back out so a constant diameter of stretchy fabric hugs the whole arrangement very well along the entire length. Make the diameter sufficient for the bottom with the fabric stretching a bit, and put in a pull string in the hem around the top in case it needs a bit of snugging down.
Just get a big rectangle and sew it up the side and put hems at both ends with a drawstring at the notional top end.
Note that the bottom only covers the lower end of the truss; it doesn't pull out to cover the mirror box. Install it before installing the upper cage, and pull it up just to cover the lower end of the cage. Mine is still going strong after 12 years of use.
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Jim
A Bad Night With A Telescope
Beats A Good Night Doing Anything Else
Teeter 18" Truss Dob/Sky Commander DSCs, "Derrick"
Meade 10" LX-5 SCT/Atlas-G "Ol' Blue Eye"
Orion 90mm refractor,
Meade 10" Starfinder Newt/JMI NGCMax DSCs,
Celestron 10x50 Ultima Pro
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dave b
Post Laureate
Reged: 05/10/05
Posts: 3875
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a few pointers for the non tailor:
any place you have cut the fabric needs to be dressed with pinking scissors (the ones that give the zig zag edge). otherwise the edge will unravel over time, ruining your hard work.
the super light weight 'rip stop' nylon makes the best shroud material. stretchy material will allow dew to drip through onto the primary mirror and those tiny holes that invariably appear will continue to grow until they ruin the shroud.
use Pi to get your length of fabric on the UTA.
pin it together for a test run, then sew it using the 'long stitch' mode on the machine. that way if you made it too tight, you can easily remove the seam.
when you are sure its right, sew a permanent seam with nylon thread.
use scrap material to double up the section of the shroud directly across from the focuser, this makes it 100% light tight at this critical point.
you can use a drawstring or elastic to snug up the shroud at the UTA end
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dave bonandrini
30" f/5.2 Dobsonian
President of GCAC
Astromart Moderator
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blueman
Vendor Blue Sky Accessories
Reged: 07/20/07
Posts: 1799
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To make one on the cheap, go to the local fabric store. There is a tube fabric available in black that will fit most scopes 14" or less. You buy it by the yard and the length would be longer than the truss tubes so that it can be folded under and sewn with a standard sewing machine.
The fabric will stretch quite a bit but when you sew the ends you must be sure to use a stretch stitch as this will allow the material to stretch.
This material forms a tube, so it is already to use once a hem is sewn.
You will find that it will fit top to bottom, a little tighter at the bottom of course.
Blueman
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14.5" Starmaster with ServoCat and Argo Navis
1966 Unitron 4" Model 152 EQ
AT 8" RC
TV NP101 f/5.4 APO Telvue .8 Focal Reducer
FLI ML8300 and CFW-2-7 filter wheel
FLI RGBL 2" filters Baader 2" Narrow Band Filters
SBig ST2000xm with CFW-9 filter wheel
Astrodon Gen2 filters RGBL
Baader HA,O-III, H-Beta, S-II Filters
ST80 Guide Scope Orion SSAG Guide Camera
Losmandy G-11 Gemini Auto-guided
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Luigi
Postmaster
Reged: 07/03/07
Posts: 5272
Loc: MA
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>>>use Pi to get your length of fabric on the UTA. <<<
Actually, it's easier and more accurate to use a tape measure and measure the actual circumference, as is done when sizing or sewing clothing...although for some of us, pi times our diameter is close enough.
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17.5" f/5 Dob. IM-715 MCT. 120ED. Lunt 60mm Ha.
Zeiss, Leica, Fujinon, Nikon, Pentax, Bushnell bins
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