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#1 saemark30

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Posted 02 April 2013 - 12:13 PM

I'm looking to rebuild a 10" Newtonian. What are the better makers of mirror cells and secondary supports?

Who sells tubes of 12" dia. or so?

#2 Pinbout

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Posted 02 April 2013 - 02:42 PM

a 10" cell is easy enough to make, or you could spend 300 for an aurora precision cell that you still have to glue to your mirror...

draw it up.

Posted Image

then cut it up.

Posted Image

#3 Pinbout

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Posted 02 April 2013 - 03:02 PM

i forgot to say, i could have had the two plates and rocker bars waterjetted out of 1/4" alum for only $40 labor $20 material. I just wanted to make it out of wood this time for the halibut.

#4 saemark30

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Posted 02 April 2013 - 03:41 PM

I bet it looks great in alum too. I could modify an existing cell with rocker bars.
What do you use for a secondary holder and spider Danny?

#5 davidpitre

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Posted 02 April 2013 - 04:03 PM

How thick is your mirror?
Here is a nice cell: http://www.aurorap.c...mirror-cell.htm, though it requires silicone. Carl Zambuto says silicone works great on these smaller mirrors. I wouldn't be big on it, but I sure wouldn't argue with Carl. I believe Portaball silicones their mirrors in , and few have anything bad to say about that set-up.
JPAstrocraft will also make you a 6 point cell for your 10". He does wonderful work: http://www.jpastrocraft.com/cells.htm ...and you get edge support.
Some of the better secondary mirror supports come from Astrosystems and Protostar.
Protostar sells a nice non-metallic tube. Hastings is likely the least expensive place for aluminum tubes. There are now several places for carbon fiber 12" tubes if that is what you are after.

#6 saemark30

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Posted 02 April 2013 - 05:13 PM

The mirror is around 1 3/8" thick.

Who makes carbon fiber tubes?
They are very expensive.
Would it be practical to make one?

#7 Pinbout

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Posted 02 April 2013 - 05:17 PM

astrosystems for secondary spiders

#8 Pinbout

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Posted 02 April 2013 - 05:27 PM

Optical Support - $229

but they're temporarily off line 6-12 months.

#9 Starman1

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Posted 02 April 2013 - 05:32 PM

Mirror Cells, cell parts, and knowledge about them:
http://web.telia.com...der/spider2.htm
http://astrosurf.com/altaz/astatic.htm
http://aurorap.com/p...mirror-cell.htm
http://www.bellevill...le-washers.html
http://www.davidlewi...plop/design.htm
http://www.dobstuff.com/mirrorcell.htm
http://www.cruxis.co...ecalculator.htm
http://www.jpastrocraft.com/cells.htm
http://www.mcmaster....springs/=gmve8g
http://www.greenhulk...t=104558&page=2
http://www.meridiant...imarymirrorcell
http://www.atmsite.o...ells/index.html
http://www.cruxis.co...rrorcooling.htm
http://www.oneilphoto.on.ca/news.htm
http://www.opticalsupports.com/
http://www.davidlewistoronto.com/plop/
http://astrosky.home....com/price.html
http://www.universit...g-supplies.html

I do not recommend a full-tube scope, even if the scope will be housed permanently in an observatory. If Alt-Az, the center of gravity will be too high, a rigid-enough structure will weigh a huge amount in any size over 12", and mirror cell design will make insertion of the mirror and cell difficult because of weight. In a truss design, the structure can be very rigid yet significantly lighter. And, the scope will be easier to construct and transport.

This is less of a problem for a 10", but even then, finding a rigid non-steel tube of 12" I.D. will be difficult and expensive. You could almost make the entire housing for the price of a tube, if the tube is fiberglass or phenolic materials. Carbon fiber would be difficult to find, and an aluminum tube will be fairly heavy if you find one that big.

There are just so many advantages to the truss design, I can't recommend a tube for your scope. 8" and smaller, maybe. But the only reason to have a 10" tubed scope is because it came that way, IMO.

#10 rgconner

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Posted 02 April 2013 - 05:45 PM

Carbon tubes are easy to come by on the web...

but you are looking at around $1200 or more.

#11 Pinbout

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Posted 02 April 2013 - 07:16 PM

you can get a wood 12" tube

Aitwood Anerson for $127

#12 Pinbout

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Posted 02 April 2013 - 07:18 PM

don astrosky and optical support are down not out but astrosky won't be back till 2015.

#13 Pinbout

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Posted 02 April 2013 - 07:30 PM

shapes unlimited also sells cardboard tubes

you have to order their standard sizes

but I got a 10in x 96in which they cut in half for ~$70

#14 Daud

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Posted 02 April 2013 - 08:51 PM

What about cost and source for carbon fiber trusses ?

#15 Starman1

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Posted 02 April 2013 - 09:32 PM

What about cost and source for carbon fiber trusses ?

Saw one quote recently for about $180 per foot.

#16 herrointment

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Posted 02 April 2013 - 10:38 PM

Danny...way cool links. Thanks!

#17 Pinbout

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Posted 02 April 2013 - 11:27 PM

both places will veneer the tubes for ya if ya don't won't to bother with that type of work. :grin:

#18 Chucky

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Posted 03 April 2013 - 05:57 AM

Anyone remember California Tubular Designs from ....oh say 10-12 years ago? Mark Wagner used to do some pretty cool custom tubes. I use one for my 10 inch F6. Is really nicely constructed with strong, good looking covering. Has strengthening end rings too.

#19 gaz-in

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Posted 03 April 2013 - 06:48 AM

How thick is your mirror?
Here is a nice cell: http://www.aurorap.c...mirror-cell.htm, though it requires silicone. Carl Zambuto says silicone works great on these smaller mirrors. I wouldn't be big on it, but I sure wouldn't argue with Carl. I believe Portaball silicones their mirrors in , and few have anything bad to say about that set-up.
JPAstrocraft will also make you a 6 point cell for your 10". He does wonderful work: http://www.jpastrocraft.com/cells.htm ...and you get edge support.
Some of the better secondary mirror supports come from Astrosystems and Protostar.
Protostar sells a nice non-metallic tube. Hastings is likely the least expensive place for aluminum tubes. There are now several places for carbon fiber 12" tubes if that is what you are after.


Chatting with Steve Swayze last weekend. He too speaks highly of siliconing mirror to cells.

#20 davidpitre

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Posted 03 April 2013 - 07:20 AM

Optical Support - $229

but they're temporarily off line 6-12 months.

I have a hard time with this cell for a standard (not conical) mirror. The 10" has 4 fixed points for bottom support. How is this a good idea?

#21 Pinbout

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Posted 03 April 2013 - 09:38 AM

The 10" has 4 fixed points for bottom support. How is this a good idea?



it has 6 supports according to this drawing

#22 Jeff Morgan

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Posted 03 April 2013 - 09:55 AM

What about cost and source for carbon fiber trusses ?


A google search will turn up many suppliers. I priced this out a couple of weeks ago. The bottom line is around 12x the cost of anodized aluminum.

On my scope it worked out to around $1500 to drop the center of gravity about 1-1/2".

Perhaps in a few more years additional production capability will come online to satisfy the demands of aerospace.

#23 Pinbout

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Posted 03 April 2013 - 10:22 AM

dragon plate 1" x 72" braided cf tube $126

Moonlite 1" x72" anodized alum. $18

CF x7 more.

#24 davidpitre

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Posted 03 April 2013 - 11:56 AM

The 10" has 4 fixed points for bottom support. How is this a good idea?



it has 6 supports according to this drawing

It looks like you are right, but that doesn't seem any better if they are all fixed. Certainly they don't provide equal or uniform support. For most 10" mirrors I'd rather 3 fixed points than 6.

#25 gaz-in

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Posted 03 April 2013 - 12:19 PM

at $45 this one looks interesting

19 MM OD by 48 inches CF Pole






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