11" project

[The Warthog]

A friend of mine sent me an 11.5" mirror that he had lying about in his garage, with the suggestion that I may want to do something with it, like make a dobsonian. Well, I can't turn down a challenge like that. I've been out pricing birch plywood for a structure, and I think I may go with sonotube for the tube at first, and build a proper truss tube later. All I really need to buy is a focuser and a spider.

I don't know how I deserve friends like this, but I can't argue. I'll post pics as I move along with the project. Probably be here asking for advice, too.

[GazOC]

Nice one!!!

[MartinB]

Good luck with that WH. Sounds a great project

[centroid]

An interesting project indeed!!

I'll be watching your progress with interest, keep the updates (and pictures) coming

Dave

[DanDare]

11.5"!!!....you just had to go one better, didn't you? :D

Good luck with that WH, keep us posted.

Roy

[Kaptain Klevtsov]

I'd stick with the tube WH, if you have light pollution, that way you don't need a light shroud. The Skelescope that I built lets lots of light in from the wrong places through the framework so I'm looking at turning it into a tube version soon. Best of luck with the project!

Kaptain Klevtsov

[barkis]

You are lucky to have a friend so generous WH.

Do you know the focal length yet. Is the coating in need of re doing, or is it servicable do you reckon?

Ron.

[The Warthog]

It is serviceable as is, and the ratio is about f/6, but my friend is mailing me the technical specs which he forgot to put in the box. It has a turned down edge, which when masked makes the mirror about 11", but the coating is not too bad as it is.

[barkis]

Pity on the TE WH, You can make a retaining ring to fit the cell that will mask it no problemo.

You have a nice project there, and you will enjoy putting it back into service I'm sure.

If we can give any advice or help in any way, don't hesitate, although you are pretty handy with the tools as we've seen in the past.

Ron.

[The Warthog]

Thanks! My friend also sent me the edge mask he used with this mirror, so I'm very well looked after. 8)

[The Warthog]

I'd stick with the tube WH, if you have light pollution, that way you don't need a light shroud. The Skelescope that I built lets lots of light in from the wrong places through the framework so I'm looking at turning it into a tube version soon. Best of luck with the project!

Kaptain Klevtsov

I would agree, KK, except that a truss is so much more sexy and high-tech looking. I will get Mrs. Warthog to sew a shroud for it. I'm sure she will if I point out that it can come in handy later on...

[barkis]

That's some sense of humour you have . :laughing2:

[The Warthog]

No, no! I was serious, honest! I just did some measuring. The glass is 11 3/4" in diameter, and with the turned down edge, I have 11 5/16" actual reflective surface. The glass weighs 13 lbs (6kg). It has a few minor marks o the surface, but can go a long time without resurfacing. I'll post a picture later.

I'm not excited about this at all, of course.