24" mirror cell.

[Orion]

Hi all, it's been a while since I posted anything but here goes.

I first started thinking about designing this mirror cell about 6 months ago with the idea of having the tailgate fold down for easy access mainly when the mirror needs a bit of a wash, considering that the mirror will be 24inches in diameter I rather not have to lift it out for cleaning.
It had to be aesthetically pleasing and I also wanted more than one fan for cooling purposes so I got on the CAD and away I went.

This is where I got to in about four months of work (on and off) The mirror cell and tailgate are constructed of mild seel, stainless and aluminium. Knowing a bit about spraying cars I used this technique with the metallic blue on the triangles and the tailgate. All the paint work has been hand polished and the collimation knobs have been machined out of aluminium and polished.
The stainless steel wire cable has to be installed and the fan at the bottom, besides that it's pretty much finished.

Hope you like:)

[cristian abarca]

Very nice piece of work. Now I know what I have to achieve when I make mine for my 19 inch.

Regards Cristian

[Starkler]

Gee that looks nice!

How much would you expect to pay ? :whistle:

[[1ponders]]

Wow Ed, what a ripper. It looks like a contempory piece of sculpture.

When do you expect first light?

[Lester]

Wow Ed,

they will me lining up to look through this one, 24".

[Orion]

Thanks All.
I don't really know how much it will cost but going by the 18" that built I think it will cost around the same because I still have most of the building materials from the last project.
I will also add the argonavis and the servocat from the 18".

As first light is concerned :shrug: ...This is a labour of love and as with the 18" it might take a couple of years,
I'm in no rush.

[h0ughy]

pretty ordinary effort there Ed:eyepop: ! Its missing a fan, few screws, the hunk of glass, a few trussy bits , the other hunk of smaller tin reflection bit and a jam tin focuser:D ;)

[Orion]

Hi Houghy, Gee I missed your input!

Well at least you didn't call it an oversized wizbin!:lol: :screwy:

[h0ughy]

you right ED, you need some glad garbage bags for the shroud!:lol:

[acropolite]

Work of art Ed :thumbsup:

[stringscope]

Very nice Ed. Did you use PLOP to determine the support point locations?

Cheers,

[Orion]

I sure did. PLOP takes out the guess work when comes to mirror cell design.:thumbsup:

[Ambermile]

24" :eyepop: Thought mine was rather large! What mirror's going in there? I have BVC 'cos it cools down faster and that's a lot of heat to lose... and I only got a 27 point cell...

Arthur

[Orion]

Hi Arthur
The mirror is a home made mirror, it's in the rough grinding stage at the moment and we are experimenting with thin mirrors.

[astroron]

Hi Ed, my suggestion for a mirror cell I was asked to build for someone was the tailgate design as his mirror is 22", I never built it in the end as the job went to Peter Reid.
Nice looking piece of work, also good to see a post from you.
There is a nice bright supernova in Ngc 1316.:thumbsup:

[Ambermile]

:eyepop: Beats me that grinding... I bought mine roughly ground to f/4.8 but parabolic. It's away in a few days to have final configuration and alumising/quartz coating. I have a set of steps :D

Arthur

(if you're interested... http://myweb.tiscali.co.uk/ambermile/dob.htm )

[Orion]

A bright supernova, thanks for the heads up Ron.

I'll have to get up early in the morning to have a look.

[Orion]

Nice telescope.:thumbsup:
It's a different style.
Having a narrow mirror cage do you experience problems with stray light?

[Ambermile]

Hi Orion

Well, as I said the mirror's not had the final configuring done yet so only an uncoated startest but yes, there is a small issue there. I also have maybe a round 48" baffle that sticks to the outside of the secondary cage to stop this though. Only needed if there's a light problem though and I don't intend to take this scope to places like that ;)

It may be that once it's finished it will become more of an issue but I do also have a lycra shroud for it - because of the 6-pole design though it needs a couple of 2mm fibreglass rod hoops to stop it interfering with the light path.

It's going to be cool when it's finished though, all the woodwork is in the paintshop at the moment. Primary and secondary mirror boxes will be dark blue fleck and the rocker box silver :D

Arthur

PS - I should say it was not built by me, rather by Frank Milsom here in the UK. Here's the first prototype he made. Explains why he did things the way he did...

http://www.fmilsom.demon.co.uk/10-inch/ten-inch.htm