Orpington Astronomical Society

Astronomy => Telescopes Etcetera.... => Topic started by: mickw on Aug 31, 2009, 11:55:37

Title: Pimp my Dob
Post by: mickw on Aug 31, 2009, 11:55:37
I've started to strip down the lightbridge to clean it and repaint as necessary.

I've got the primary out of the tube but it seems attached to the carrier - Is it glued in or is it more likely to be crup ?
Would soaking shift it ?

Oh, I'm also gonna wait until the sun goes behing the house afternearly cooking my belly  :oops:

Cheers

*Sorted, double sided tape now sliced through with dental floss*  :o
Title: Re: Pimp my Dob
Post by: Mike on Sep 02, 2009, 13:34:00
I've got a really bad feeling about this.
Title: Re: Pimp my Dob
Post by: mickw on Sep 02, 2009, 15:33:23
Nothing to fret about, got most of the crud off with brillo pads and ajax  ;)
I remembered what you said about only wiping the pads across the mirror once  :)

OK, at ease  :lol:
I wanted to get the mirror out of the carrier so I could clean it without making anything else rusty
Propped it up at about 30 deg. and used a spray of ordinary water for about 10 mins to soften anything that wasn't soft, then flooded it with de-ionised water.
Then couple of drops washing liquid in de-I water wiped with pukka cotton wool to remove somones fat finger mark on the edge  :oops:
Then wiping with straight de-I water and cotton wool (one wipe per cotton ball).
Finally blow dried with hot air gun at about a foot away.
Looks better than what it was but is still spotty, probably water staining.

I know it's probably OK (certainly was as DSC), but while I've got it in bits, it seems daft not to get it re-coated for the sake of £30

While that's being done I can concentrate on getting the chrome, graphics and sound system done  :lol: :lol: :lol:
Title: Re: Pimp my Dob
Post by: Mike on Sep 02, 2009, 16:19:37
After I cleaned it it had spots on it. I'm afraid it was left out in the rain once or twice too many times at DSC. But, as you say you can get it recoated for not a lot of dosh so it will be worth it to have an as good as new dob again.
Title: Re: Pimp my Dob
Post by: mickw on Sep 02, 2009, 17:41:41
I blame Swine Measles  ;)
Title: Re: Pimp my Dob
Post by: RobertM on Sep 02, 2009, 19:00:26
QuoteWhile that's being done I can concentrate on getting the chrome, graphics and sound system done

Don't forget the dice  :lol: :lol: :lol:
Title: Re: Pimp my Dob
Post by: mickw on Sep 02, 2009, 19:51:42
The dice - I forgot the dice  :o
Title: Re: Pimp my Dob
Post by: Ian on Sep 02, 2009, 22:46:30
and pink leopardskin
Title: Re: Pimp my Dob
Post by: Whitters on Sep 02, 2009, 23:25:11
I hope you didn't forget the scented tree
Title: Re: Pimp my Dob
Post by: mickw on Sep 02, 2009, 23:51:41
Doh

Leopard skin...........
Tree..............

Memory broken...................
Must have beer..........................
:lol:
Title: Re: Pimp my Dob
Post by: RobertM on Sep 03, 2009, 07:29:39
I think the tree might defeat the photons trying to get to the mirror - Thats only my personal opinion mind you.  Remember this is supposed to be a telescope  :o 
Title: Re: Pimp my Dob
Post by: Mike on Sep 03, 2009, 08:50:09
Don't forget the 5 mile long dew shield so you can see through the clouds.
Title: Re: Pimp my Dob
Post by: Ian on Sep 03, 2009, 09:58:38
I think it'd look really trick with little blue LEDs in the windscreen washer nozzles. and fluorescent green downlights underneath so it looks like it's floating as it goes along.

Mick, are you planning on going as far as lowering the suspension?
Title: Re: Pimp my Dob
Post by: Tony G on Sep 03, 2009, 11:22:06
Mac,

Didn't you take some photos of the Dob, so people could re-design it for Mick, with pretty colours and fur etc. in photoshop.

Tony G

Title: Re: Pimp my Dob
Post by: The Thing on Sep 03, 2009, 14:56:48
Nodding dog?! Nice touch when you line up on another beer bottle deep sky object.
(http://www.allproducts.com/gift/sundeal/Product-2005111455519.jpg)
Title: Re: Pimp my Dob
Post by: Ian on Sep 03, 2009, 15:27:06
with a fricking laserbeam on it head...

(Scuse me while I go for a lay down)
Title: Re: Pimp my Dob
Post by: Mac on Sep 03, 2009, 18:07:57
Quotewith a fricking laserbeam on it head.

GREEN EYES.

You know who you are............. 8)
Title: Re: Pimp my Dob
Post by: mickw on Sep 03, 2009, 20:43:55
Quoteare you planning on going as far as lowering the suspension?

I have to be careful, last time I lowered my suspenders I got into trouble with the police  :oops:

QuoteGREEN EYES - You know who you are
Mac, you only have yourself to blame, you should not have let Daft Ada play with your light sabre  ;)

Dew shield on order from Telescope Planet - Not holding my breath  :-?

QuoteNodding dog
I was thinking of being subtle, something like sheepskin cover - No offence Tony.
With added LEDs and cold cathodes to cheer the chaps up at Kelling Heath  :twisted:

Must go, more stuff to order


Title: Re: Pimp my Dob
Post by: Fay on Sep 04, 2009, 14:05:16
Mick, should that have been "Primp my Dob?"
Title: Re: Pimp my Dob
Post by: Ian on Sep 04, 2009, 14:15:16
or "pump my deb?"
Title: Re: Pimp my Dob
Post by: Rick on Sep 05, 2009, 09:08:26
or...

No. Some suggestions are better left un-written.

:twisted:
Title: Re: Pimp my Dob
Post by: Fay on Sep 05, 2009, 09:42:29
sorry Rick
Title: Re: Pimp my Dob
Post by: Rocket Pooch on Sep 06, 2009, 16:30:38
Quote from: mickw on Aug 31, 2009, 11:55:37
*Sorted, double sided tape now sliced through with dental floss*  :o

Hi,

I have just re-fitted the primary back into my scope and added some bobbs knobbs (there great) when you replace the 9 sponge mirror holders use some double sided foam, you can get this from a craft shop, if you can't find any I have some left and I'll get it too you later this week.

Also I have taken out all the old collimation screws from mine, if you need any new ones (from my unused scope) let me know.

My Dob is now pimped, flocking behind the secondary, bobbs knobbs, stronger springs etc, and I had a laugh centre spotting the primary :-)  My newly coated primary is fantastic!


I't will be making an appearance on an EQ6 as soon as I can find some better counter weights.

Chris



P.S. Robo focus will also be on it soon :-)
Now where's Jupiter?
Title: Re: Pimp my Dob
Post by: mickw on Sep 06, 2009, 18:36:52
I'm going to take my primary to Basildon some time this week, possibly tomorrow.
Bobs knobs and springs also on order 8o)
Made a new az tension knob due to surplus of araldite on original, made new alt friction pad due to it being concave  :-?
I've got some d/s foam tape thanks anyway  8)

I'd thought of flock, but didn't want to make it too cozy for the spiders so I'll be taking the secondary and (other) spider out to respray the inside with matt black.

Collimation, after reassembly, may be entertaining - I'm thinking of selling tickets  :lol:

Title: Re: Pimp my Dob
Post by: Mac on Sep 06, 2009, 21:04:18
QuoteI'm thinking of selling tickets

I'll have two for the front please. Or i can swap you an entry ticket for Chris Lintott  ;)
Title: Re: Pimp my Dob
Post by: Fay on Sep 06, 2009, 22:17:15
I will have a ticket...could be a bigger demand than for CL!!!!!!!!
Title: Re: Pimp my Dob
Post by: Tony G on Sep 06, 2009, 23:19:43
Chris who?   :-?

Tony G
Title: Re: Pimp my Dob
Post by: mickw on Sep 23, 2009, 14:00:01
Just picked up the mirror after re-coatong - Ooh Shiny  :)

The centre collimating dot has gone though, fortunately this means I will now be in a position to destroy all the  fine work Galvoptics have done  :cry:
Title: Re: Pimp my Dob
Post by: Ian on Sep 23, 2009, 15:31:46
Mick, you can mark the centre of the mirror using a centre punch and a good size hammer. Make sure you use a reasonably large hammer as glass is hard and doesn't dent very easily.
Title: Re: Pimp my Dob
Post by: mickw on Sep 23, 2009, 15:49:56
Should I put a piece of tape in the middle to stop the punch slipping  :)
Title: Re: Pimp my Dob
Post by: Simon E on Sep 23, 2009, 15:53:15
I would use a hammer drill, worked for me when i was mounting a rear view mirror in the other half's car :o

si
Title: Re: Pimp my Dob
Post by: Fay on Sep 23, 2009, 16:52:50
I think this is going to call for a soothing drink Mick, don't like to force you though :lol:
Title: Re: Pimp my Dob
Post by: Tony G on Sep 23, 2009, 17:00:41
Mick,

Speak to Chris, as he had the same problem to overcome.

Tony G
Title: Re: Pimp my Dob
Post by: mickw on Sep 23, 2009, 17:21:01
Quotea soothing drink
QuoteSpeak to Chris

Both admirable suggestions..............................
As I may see Chris on fight night, it leaves this evening free for Fay's suggestion  :lol:
Title: Re: Pimp my Dob
Post by: Rocket Pooch on Sep 23, 2009, 22:14:08
Quote from: mickw on Sep 23, 2009, 14:00:01
Just picked up the mirror after re-coatong - Ooh Shiny  :)

The centre collimating dot has gone though, fortunately this means I will now be in a position to destroy all the  fine work Galvoptics have done  :cry:

Ah ha, ok thats easy to cure, I used to pieces of cotton and just taped them at right anges until I thought they crossed ok then I measure it just to check, took 5 mins.

John, your technique is safer, can you explain?
Title: Re: Pimp my Dob
Post by: JohnP on Sep 23, 2009, 22:36:19
It was something along lines of get a sheet of paper (probably A3 for your mirror) & draw a circle on it same diameter as mirror. Cut it out & fold in quarters to find centre. Then cut a small hole (slightly larger than one of those sticky paper reinforcers in the middle). Lay paper on mirror & then gently place hole reinforcer sticky side down in midle hole...

Hope that makes sense,

john
Title: Re: Pimp my Dob
Post by: mickw on Sep 24, 2009, 01:27:41
Thanks for that chaps, John's way sounds safest for me - it'll keep my fat fingers away from the surface.

Sadly it sounds like a "no beer" job  :(
Title: Re: Pimp my Dob
Post by: mickw on Sep 24, 2009, 23:58:31

Forgot to mention tonight..................
As you know the lightbridge is completely stripped down - possibly a bad move removing secondary from spider though  :-?

After the spotting of the primary and reassembly will come the C word - collimation.
I intend to use the method demonstrated by Chris at Blacklands - eyeball down the tube at 20 paces to adjust the primary, then align the secondary to the primary as it will also be completely out of whack.
I'm thinking that I should at least be able to get something reasonable as a starting point for proper alignment later.

Am I going about it the right way ?
Title: Re: Pimp my Dob
Post by: Mike on Sep 25, 2009, 07:47:30
I thought you had a laser collimator? Using that is far and above the easiest way to collimate it. Collimate the secondary first, then the primary.
Title: Re: Pimp my Dob
Post by: mickw on Sep 25, 2009, 08:23:32
QuoteI thought you had a laser collimator
I have, I was just thinking of getting things eyeballed first as everything is/will be really messed up  :(

So, laser it is then  :)

Cheers
Title: Re: Pimp my Dob
Post by: Ian on Sep 25, 2009, 09:10:59
you will of course put the fricking laser on your head, won't you...
Title: Re: Pimp my Dob
Post by: Rocket Pooch on Sep 25, 2009, 09:57:19
Quote from: Mike on Sep 25, 2009, 07:47:30
I thought you had a laser collimator? Using that is far and above the easiest way to collimate it. Collimate the secondary first, then the primary.

Hi,

Because its a parabolic mirror (like a bowel) you can use a laser align it and still have the mirror out, the think I showed Mick was just to ensure the primary was set first.

Then use the laser.

Chris
Title: Re: Pimp my Dob
Post by: mickw on Sep 25, 2009, 10:23:11
Yep, that's what I meant  :oops:
Title: Re: Pimp my Dob
Post by: Ian on Sep 25, 2009, 10:31:42
Mick, have you got access to a cheshire? Once you've got your head around what you're looking at (and that's not hard, start from the outside and work in, they work a treat.

This (http://www.propermotion.com/jwreed/ATM/Collimate/Chesire.htm) is one of the best explanations I've seen on using one, including a discussion regarding what doesn't get centred (hint, the secondary reflection *shouldn't* be centred).
Title: Re: Pimp my Dob
Post by: Fay on Sep 25, 2009, 10:42:52
Think it may call for a drink when you have read the article, Mick, it made me head for the bottle!! :o
Title: Re: Pimp my Dob
Post by: mickw on Sep 25, 2009, 12:09:34
Quotemade me head for the bottle!!

Hmm, wise words  ;)

I think I'll make a start before I read it  :D
Title: Re: Pimp my Dob
Post by: Ian on Sep 25, 2009, 12:12:48
DON'T try and understand it without having the scope in front of you. You'll never do it. All you'll do is lever your brain out of your nose, which won't be pretty.

That's the clever bit when using the force to move starships. You have to brace your brain so it doesn't get squeezed down your spinal column.
Title: Re: Pimp my Dob
Post by: Fay on Sep 25, 2009, 12:16:29
bet you're looking forward to this Mick! :o
Title: Re: Pimp my Dob
Post by: mickw on Sep 25, 2009, 12:33:26
QuoteDON'T try and understand it without having the scope in front of you

Doh - too late  :(

I did note that I should have centred the spider though  :oops:

Fortunately I haven't got a cheshire but I have faith in eyeball laser and luck  :lol:

I've got a bit more tinkering to do including changing the dots I bought instead of rings to mark the mirror  :(

Is it beer o'clock yet ?
Title: Re: Pimp my Dob
Post by: Ian on Sep 25, 2009, 12:53:43
you can try with the laser mate, but it won't help do the whole job. Which is what you have to do seeing as you've taken the whole kit apart.

You will end up with a cheshire, one way or another... :)
Title: Re: Pimp my Dob
Post by: mickw on Sep 25, 2009, 13:27:44
Ordered  :(

Title: Re: Pimp my Dob
Post by: MarkS on Sep 25, 2009, 13:42:11
Quote from: Space Dog
Because its a parabolic mirror (like a bowel) you can use a laser align it and still have the mirror out

Bowel?!?
Title: Re: Pimp my Dob
Post by: Ian on Sep 25, 2009, 13:43:18
I took that to be a critique of Meade manufacturing capability.
Title: Re: Pimp my Dob
Post by: mickw on Sep 25, 2009, 13:59:32
No, it's because it looked like sh~t before recoating  :lol:
Title: Re: Pimp my Dob
Post by: Fay on Sep 25, 2009, 14:14:02
Mick, I have a Cheshire, Robert has it at the moment, but you are welcome to try it.
Title: Re: Pimp my Dob
Post by: mickw on Sep 25, 2009, 14:40:06
Thanks Fay that would be great - can you go round and beat Robert up to get it by tonight  :twisted:

It's Ok I've ordered one, should have it tomorrow, I'm bound to bugger up the lightbridge again   ;)
Title: Re: Pimp my Dob
Post by: Ian on Sep 25, 2009, 14:42:18
if you had marked your centre spot with a hammer and centrepunch all your collimation issues would have gone away. It's hardly our fault you can't follow basic suggestions now, is it?
Title: Re: Pimp my Dob
Post by: mickw on Sep 25, 2009, 15:08:12
Damn - I thought you were joking  :(

I'll remember next time   :roll: