Noooooooooooo, clunk, **** :-( :-(:-(

[pel]

Morning all ,

I stupidly tried to collimate my secondary mirror last night vertically while I was tired and dropped that stupid yellow screwdriver down the tube resulting in a 2-3mm chip about 30mm from the centre. (I know I should be doing it horizontally). I was almost too embarrassed to post.

I plan on going out tonight to survey the damage, but want to be prepared, how bad will this affect the scope?

Can I buy a new primary, does anybody know how much and where ?

Thanks, Perry

[JamesF]

There was another thread about replacement parts for Skywatcher scopes recently. I can't recall the title at the moment though. I believe the conclusion was that OVL can supply spares.

Or, if you're willing to take the risk, there's a 200P mirror set on astroboot at the moment.

James

[pel]

Thanks James. I've emailed OVL.

I'm not sure on the condition of Astroboot mirrors and whether I could fit them. It's a bit of a worry that 2nd hand mirrors are £115 though :-(

Think I may tatoo don't collimate vertically on my forehead :-)

[palebluedot]

Bad luck! I did something similar, and got the following advice from Ant.

"With any luck the damage will be to the coating only. For a fairly low cost you could have the mirror re-coated.

Several places do it, including Galve Optics in Basildon, Essex and Orion Optics uk (although I am sure that there are others).

If you keep the scope for a few years this is something that you may consider doing anyway."

I have not bothered yet. No noticeable difference in my case.

HTH

[michael.h.f.wilkinson]

Small nicks in mirrors have comparatively low impact on image quality. They mainly add a bit of scatter, so contrast is lowered. The light-gathering surface area is hardly affected. The worst impact (if visible at all) will be on planets and the moon (and double stars maybe), but not on fuzzies.

[Daniel-K]

2-3 mm wont affect your veiwing much but it might have chipped the glass aswell (dont want to scare you) i have just bought a mirror from scopes and skies they are very good and provided a good service. the mirror it self is very easy to take out the tube if you look at the bottom you will see its held in by phillips screws all the way around all you have to do is take them out and your mirror and cell will come out. the mirror from scopes and skies comes with a cell too so all you have to do is pus the new one in and screw the screws back in and recollimate any questions drop me a pm

[Macavity]

Many people work with dusty optics? A random thought... A chip would not *scatter* light, if filled with matt-black paint? <G> The same idea that "holes" in solar film can be cured with tipex? Saddening certainly, imperfect maybe, but worth a TEST, *before* forking out for a new mirror immediately?

[Stephen]

The chances this will impact your visual use (or probably even imaging use!) are so small I wouldn't even worry about it until

a) The problem is seen visually.

The mirror falls apart (highly unlikely ...)

Reflectors can and are used with chunks missing out of them, scratches on them, all sort of crud on the mirror ...

Whilst it's going to hurt resale, I really don't think you've any reason to worry at this point You don't need to buy a new mirror or recoat it!!!

30mm from the centre "may" even be hiding in the shadow of the secondary

[themos]

Just cover it up with something non-reflective, it won't appreciably affect your light gathering and will only damage the wavefront less than the atmosphere already does.

[runoffshed]

Don't be embarrassed, Pel, we all do daft things from time to time...me more than most...

But whenever I do, I console myself with the thought that at least I didn't send a 2.4 mtr 'not fit for purpose' mirror into space in a much anticipated 1.5billion dollar project. Nor did I lose a 125 million dollar Mars orbiter because at some point someone forgot to say " so this is in Kilometres, right?"

Suddenly, our mistakes don't seem so bad after all.

[perrin6]

Is it just the coating that's chipped off (v. thin) or does it look deep ?

[pel]

Thanks everyone, that was brilliant advice from all of you. I'm always amazed by the great advice I get on here, even if I am being incredibly stupid.

It seems to only be a bit of the mirrored surface, that has come off, so I will paint it black. I can't believe I may have got away with something so dumb, I only read the day before to collimate the secondary horizontally :-)

OVL responded very quickly and said I should be ok too.

There isn't any danger of me getting rid of the scope for a long while Khelder, so I'm not worried about the resale value.

Thanks John, the hubble mirror problems put my mistake into some perspective.

I feel a lot better now, thanks guys.

[Gina]

"Paint it black" - the damage that is. Like the others I'm sure you won't notice the difference. It's more psychological than real damage to the light gathering properties.

As for being embarrassed, don't worry - I ruined (I believe) a DSLR camera body by trying to be too ambitious. I paid over £300 for it but managed to replace it for £230. I was embarrassed, I can tell you!! That's calmed me down a bit

[pel]

Thanks Gina, yes I read about your camera body. I felt really bad for you. It looked a very technical job though and the instructions seemed to differ from your camera. My 350D seems easier to work on, but I am going to wait a while until I recover from this ordeal :-)

[Shibby]

Hi Pel, I did something very similar... I used to use a compass which just happened to be a "good" fit as a lens cap on my camera adapter. One time, I forgot that I'd left it on while attaching the camera to the focuser. Of course, it fell inside the tube and with a horrible *clang* took a chip out of both my pride and the primary mirror of my brand new 150PDS

However, the scope performs perfectly well. Beyond my expectations, if anything! So I don't think you have anything to worry about

[pel]

Thanks Lewis, I was inconsolable last night. I'm glad I posted on here it has really cheered me up.

I'm glad I'm not the only one that's done this.

I was worried that every photo I took from now on would be spoilt by my mistake.

[themos]

I was worried that every photo I took from now on would be spoilt by my mistake.

well, to be fair, that's still likely to be true.

The fault, dear Brutus, is not in our stars,

But in ourselves, that we are underlings

[Moonshane]

I agree on the put a black dab of matt paint on it and forget it. As already mentioned the secondary may well hide it anyway and the chances of seeing it (unless you look down the end of the scope) are minimal.

[pel]

Thanks guys, not you though Themos :-)

[michael8554]

I'm not familiar with the scope, but maybe some thumbscrews can be fitted, to avoid a repeat?

[JamesF]

I'm not familiar with the scope, but maybe some thumbscrews can be fitted, to avoid a repeat?

I think that's quite a harsh punishment for dropping a screwdriver.

James

[pel]

:)

[michael.h.f.wilkinson]

BTW,"Noooooooooooo, clunk" sounds like your focal length is HUGE

[pel]

Time slows down when you do something like this, so I probably had time to say all that in my head :-)

[Moonshane]

Time slows down when you do something like this, so I probably had time to say all that in my head :-)

Just like when your biscuit is about to snap off and fall into your tea!