[Garyh]

Originally Posted by uyukon

Hi Gerry,
I dug in my papers and found out that the carbon was rather 340 Euros ( material for the tube, mirror cell+spider+ some extra, just in case something would go wrong( and it did....). I got the stuff from http://www.carbon-vertrieb.com, in case you find a cheaper supplier, please let me know, i might even consider air mail shippment for such a lightweight material.
You could also consider to make the tube out of carbon rowings (monofilament fibre).Much cheaper!
I tried but failed because of a too weak former, it collapsed when wrapping, next time I do it better.
For the 260mm o.d.tube 2mm thickness is also not nessesary, 1-1.5 will do, saves you weight+costs.

Clear skies!

Thanks Uyukon for that info, I will have to chase up the prices over here to see if the cost will be prohibitive..hopefully they won`t be too expensive..
cheers Gary

Originally Posted by David Fitz-Henr

Hello Garyh,
I've actually just joined IceInSpace the other day, and I have 90% completed making some fibreglass components for a prototype telescope (sandwich core fibreglass sectioned tube, mirror cell, counterweight rings). I haven't worked on it for about a year, as I had postponed it to construct an observatory which is still in progress. It is my second fibreglass project, the first being a laundry chute I made a few years ago.

Here are a couple of web pages I can recommend having a look at :
http://astro.umsystem.edu/atm/ARCHIV.../msg00540.html
http://www.geocities.com/natsp2000/fiberglass-tube.html

I have basically learnt it by myself with just web references and supplier info pamphlets for instruction - needless to say it has been a learning experience. However, I haven't tried carbon fibre yet - it costs a fortune and I want to perfect my skills first. I'm glad I did, as although the tube is turning out quite good, I will do it better next time! For one thing, I used too many layers of cloth and too much resin so it is heavier than it should be (but boy is it stiff and strong!!). I don't think there is much difference in technique, although I believe that carbon fibre has different wet-out characteristics to e-glass.

For fibreglass supplies, I use the following sources:
- ATL Composites in Queensland - very helpful staff !!!!!! They also supplied pamphlets on their products and some other info. (website: http://www.atlcomposites.com ) - I use them for most of my supplies - they have specialised laminating epoxy resins, carbon cloth, etc, etc.
- Fibreglass Material Services Pty Ltd, Unit 1/ 19 Boden Rd Seven Hills 2147(02) 9624 2811. They also have a lot of stuff, but not as much as ATL. However, can be more handy as you can drop in and buy over the counter.
- Advanced Composites in Unanderra - not very helpful staff, you've got to know precisely what you want and just order it. However, I believe the company has changed hands / merged / whatever and their website is no longer active, so you would have to chase it up. They were the only place I found that supplied Nomex Honeycomb which I needed,
although there is another company in WA that may have it (http://www.fibreglass-resin-sales.com.au/home.html).

I also have heaps of pictures (and a lot of practical advice) if you are interested.
Regards,
David

thanks David... thats heaps of info for me to chew on..I shall check out the suppliers to see what they have and the costs..
Do you have any pics of how your tube is coming along..?
Thanks again for all that useful info..
cheers