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ATM telescope carbon fiber cell, spider and tube

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32 replies to this topic

#1 CanaryMax

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Posted 31 March 2013 - 05:14 AM

I present my first telescope over, is made of carbon fiber, epoxy resin, aramid and stainless steel screws.

http://canaryastro.w...lbumid=13105589

The cell and the spider are solid carbon fiber and the tube is a sandwich of fiber and aramid honeycomb.

The legs of the spider and the primary support triangles, are laminated.

The focuser is a Moonlite, which seemed too complicated to replicate in fiber :cool:

Even I have some things to give, put a fan to the cell, change the secondary adjustment screws, rings also make a solid fiber, a higher plate. But it is already operating and have also made the first light with a CCD QHY5LII.

I hope you enjoy it.

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#2 neo

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Posted 31 March 2013 - 07:23 AM

Beautiful scope :waytogo: :waytogo: !
How heavy is the tube?

#3 CanaryMax

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Posted 01 April 2013 - 04:37 AM

Thany you Alex.

Tube only 4.5 kg, is oversized, I used a 5mm thick aramid me leftover from another project, this overestimated the weight needed. For an 8", aramid core 2-3mm is enough and the weight had been 1.5 kg less.
I did not mind the weight was not very important.

All tube include rings and plate 9Kg.

Regards
Maximo

#4 careysub

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Posted 02 April 2013 - 01:15 AM

Could you show close-ups of your mirror cell and spider?

#5 timps

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Posted 02 April 2013 - 04:49 AM

Nice. I was thinking about making a 10" carbon fibre tube newt but the tube alone was going to cost $2000!

#6 CanaryMax

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Posted 02 April 2013 - 07:02 AM

Hello:

Careysub, some details of the cell, i added a fan. I dont have now image details of spider.
http://canaryastro.w...lbumid=13105589

Timps, in my local astronomical association built a 14" honeycomb core, the cost was about 1000$ only raw material, if you are talking a commercial tube does not surprise me the 2000$ costing.

http://www.aagc.es/o...orion-optics-14

#7 The Planetman

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Posted 02 April 2013 - 08:13 AM

That looks very nice!!

#8 obin robinson

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Posted 02 April 2013 - 11:52 AM

Timps, in my local astronomical association built a 14" honeycomb core, the cost was about 1000$ only raw material, if you are talking a commercial tube does not surprise me the 2000$ costing.

http://www.aagc.es/o...orion-optics-14


Good job on the tube! Materials must be very expensive where you are. I have fabricated countless aircraft parts from composites and something the size of that tube would not cost nearly as much money here. I was tempted to rebuild my Starfinder 10 out of carbon fiber. Your pictures have inspired me to look closer into it.

Great work!

obin :)

#9 CanaryMax

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Posted 03 April 2013 - 08:10 AM

Thanks Ross.

Thanks Obin, yes the material is expensive and is not where I live, I have to ask out and transport it all even more expensive.
I've added a fan to the cell and a thermometer to measure the temperature of the mirror and the environment. New images, the cell does not think touch more, if I can stand the temptation.

#10 CharlesW

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Posted 03 April 2013 - 09:19 AM

Am I seeing that your support rings are wood? If so, very nicely done.

#11 CanaryMax

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Posted 03 April 2013 - 10:42 AM

The dovetail plate and the rings are not definitive, the rings I want make them in fiber and change the plate probably a 30cm Losmandy or fiber also.
The wooden rings are beautifull but i dont like too much about the flexions induced in astrophotography, I made just to test the equipment.
What I seek is rigidity and stability of the focus to changes in temperature.

#12 careysub

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Posted 03 April 2013 - 01:49 PM

Is your cell solid core?

#13 CanaryMax

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Posted 04 April 2013 - 03:14 AM

Yes the cell and spider are solid carbon fiber, the cell has a laminated layer of fiber on the face side only for aesthetics.

#14 Geo.

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Posted 05 April 2013 - 07:53 AM

I see you covered the tube with plastic. Did you vacuum bag it? What was the weight/thickness of you fiberboard armature? Gracias.

#15 CanaryMax

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Posted 05 April 2013 - 07:30 PM

Hello George:
No, I did not use vacuum, with this type of mold if I had used vacuum, the mold would have deformed between the vanes each wooden disc.

Carbon fiber data:

Fibre: Torayca C 700 SC or equivalent in 12 k, 800 tex
Resin consumption: 465 g/m², laminate thickness: 0.65 mm, laminate weight: 865 g/m²

I used 4 turns of fiber (two+honeycomb+two) and the tube is 1m long and 0.24m diameter. The honeycomb consumpt about 1.5Kg resin.

Maximo

#16 JM La Galette

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Posted 20 April 2013 - 02:19 AM

Nice job Maximo !

Some questions please, why don't you have built the cell with honeycomb as well?

Also how did you do the solid thick part of the cell? It looks like molding coupound. Did you mold and cure it yourself?

Thanks,
JMarc

#17 don clement

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Posted 20 April 2013 - 07:42 AM

What I seek is rigidity and stability of the focus to changes in temperature.

Nice job! If change in focus due to temperature is the primary concern why not compensate using active feedback at the focuser?


Don Clement

#18 Mirzam

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Posted 20 April 2013 - 11:16 AM

There is a better way:

Mixing materials of different CTE

JimC

#19 don clement

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Posted 20 April 2013 - 11:40 AM

John Harrison invented the Gridiron pendulum that did just that. http://en.wikipedia....idiron_pendulum However there are many paths to the same solution. Using a mixture of materials such as low CTE carbon epoxy is one solution and using an active feedback focuser is another. To eliminate the effects of flexure Mark Serrurier invented a truss structure that didn’t eliminate flexure but made the effects of flexure moot.

Don Clement
110100100

#20 CanaryMax

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Posted 22 April 2013 - 12:06 PM

Hello,

JMarc: Mainly in its construction simplicity. With the honeycomb would have earned weight no doubt, but I would meant a lot more work, especially when the threads embed, reinforce those areas and find a strong system to attachment the cell to the tube. My tests making sandwiches with wood, honeycomb or solid fiber, convinced me not to use any kind of sandwich, I saw more flexible than solid fiber.
Making it solid, not had more to drill and countersink threads.
The cell was made in a negative mold.

Don Clement: Active feedback focuser is too expensive and I dont like wires and electrons... My cell has cost me very little compared and it has been relatively simple to construct.

JimC: I think is not a better way, i think is another way. For a project ATM, each seeking the solutions that are most appropriate to their circumstances. ;)

#21 don clement

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Posted 22 April 2013 - 12:30 PM

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#22 polaraligned

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Posted 22 April 2013 - 12:42 PM

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#23 BradleyB

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Posted 22 April 2013 - 09:33 PM

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#24 Howie Glatter

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Posted 23 April 2013 - 08:34 PM

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#25 richard7

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Posted 24 April 2013 - 06:24 AM

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