Carbon Fibre Telescope Finished

[TheThing]

Wow, it a labour of love, but worth it in the end.

I've never worked with C/F. Did you have to take any H&S precautions with the fibres (i.e. mask/goggles) when you cut it, or are the fibres not small enough to present a danger? Ditto the E/P - are the vapours harmful at all?

Can't wait to read your first light report!

[Astro_Baby]

wow- thats amazing stuff and it looks beautiful as well.

You should be well pleased with that.

[philj]

Interesting stuff Paul, looks a fine job. The tube build photos takes me back to fibre glass days rebuilding a Lotus Elan body.

[Astro_Baby]

Interesting stuff Paul, looks a fine job. The tube build photos takes me back to fibre glass days rebuilding a Lotus Elan body.

LOTUS - Lots of Trouble Usually Serious LOL

I used to own a 7 and later a Europa.

Oddly I was thinking the same about fibre glass - helped make a canoe once and it was kind of similar.

Whats the weight like of CF ? compared to aluminium on a scope tube.

[George]

Thats a great looking tube Paul

And the $64000 question is (Im surprised noone has asked this yet) what was the total cost for the tube build?

[paul11]

Wow, it a labour of love, but worth it in the end.

I've never worked with C/F. Did you have to take any H&S precautions with the fibres (i.e. mask/goggles) when you cut it, or are the fibres not small enough to present a danger? Ditto the E/P - are the vapours harmful at all?

Can't wait to read your first light report!

I never used a mask when I was gluing up the C/F but I did when I was using the Router and Band saw to cut it.

[Beulah]

I work with CF rods/bars and the splinters are nasssty....

Thanks Paul, I appreciate the time you have taken to answer our questions. It's one of those rare threads where communication is actually going on.

[paul11]

LOTUS - Lots of Trouble Usually Serious LOL

I used to own a 7 and later a Europa.

Oddly I was thinking the same about fibre glass - helped make a canoe once and it was kind of similar.

Whats the weight like of CF ? compared to aluminium on a scope tube.

I can’t tell you what the weight difference is between C/F Metal and Aluminium but I can tell you that this tube weighs in at 7lb and is 5mm thick. I think I better try to explain how this came about. As this was the first C/F tube I’ve made I just didn’t know how strong to make it so I ended up making it 10x stronger than it needed to be. If I made another one this size (250mm) I would use a single layer of C/F, then a layer of 1mm coremat and then one more layer of C/F and that would be more than strong enough and would only weigh about 3lb and be approx 2mm thick.

[paul11]

wow- thats amazing stuff and it looks beautiful as well.

You should be well pleased with that.

I am really happy with the tube and the mirror but this Telescope is a Prototype for the next one I intend to build.

[paul11]

Now it’s back into the workshop to cut the tube to length (1200mm). I put a 6mm bit in the Router set the depth to 6mm and used the fence and just ran it around the stop end on the tube.

[paul11]

Next I gave it a coat of Blakes 2 pack high gloss Polyurethane clear varnish and it was finished,,,,,,Paul.

[paul11]

I’m working tomorrow guys but if I get a chance tomorrow night I will let you know how I made the mirror cell,,,,,Paul.

[paul11]

Thats a great looking tube Paul

And the $64000 question is (Im surprised noone has asked this yet) what was the total cost for the tube build?

Including £40 for the cardboard tube it came to about £220. The next one I will make is going to be 1.8m x 400mm and with a slightly different design it won’t cost any more than £250 and that’s not bad for a C/F tube that size.

[Steve922]

Is that, like a 16" mirror? How long will that take to make?

Steve

[paul11]

Is that, like a 16" mirror? How long will that take to make?

Steve

It's going to be a 14" F5 mirror in a 16" tube and i think the mirror will take about 4 weeks to make if all goes well.

[mattifor]

Hi Paul

are you going into business to produce and sell these tubes?

I am realy impressed by what you have achieved so far.

Good luck with the mirror.

I look forward to your first light report.

[paul11]

Hi Paul

are you going into business to produce and sell these tubes?

I am realy impressed by what you have achieved so far.

Good luck with the mirror.

I look forward to your first light report.

No real thoughts on making them as a business but if someone did want one made I may be able to help them out. I’ve still bit a bit more to learn about the strength and thickness these tubes need to be. If the next tube I make with 1mm coremat works out ok then I think I will have it all worked out,,,Paul.

[Beulah]

How much did the mirror coating cost?

[paul11]

How much did the mirror coating cost?

It was £16 from Galvoptics

[Beulah]

Thanks, Paul.

[paul11]

Now for the mirror cell, for this I Laminated 3 layers of 3mm coremat between 4 layers of C/F. This was made up between 2 layers of 6mm glass, I put peel ply on top of the last layer of C/F to give a matt finish while the first layer of C/F was laid directly on the glass to give a gloss finish. Then a made another one with a matt finish on both sides.

[paul11]

This is how I left the C/F to dry overnight with 3 5kg weights and a bucket of water (very high tech).

[paul11]

The next morning I parted the C/F from the glass, I put a 14tpi blade in the band saw and cut the discs. With a very simple home made jig the band saw will cut perfect circles every time.

[paul11]

Here’s a close up of the edge of the disc, you can see the 3 coremat and 4 C/F. The discs finished up 10mm thick and they are really strong.

[paul11]

Here’s an image of the 2 discs, on the right is the outside disc (gloss finish) with 3 11mm holes in it. On the left is the inside disc that will hold the mirror, I drilled 3 holes and put in the 10mm brass inserts, they look great and really work well.