Loosen your screws or.....CRACK!

[bloodhound31]

If anyone has tightened their screws on the retaining ring of their corrector plate during the colder times of winter...word of advice from someone who has just learned a very expensive lesson.......

LOOSEN THEM OFF BEFORE THE SUMMER HITS!

I took the cover off for tonight's imaging to find this.

Baz.:sadeyes::(:mad2::bashcomp:

[h0ughy]

Barry I am truely sorry for your loss, i have never touched the screws on the scopes ihave owned around the corrector plate? how hot did it get in the observatory?

[bloodhound31]

Mate, I dont think it got all that extreme. But, when I last took it off and tightened it back down, temperatures here were in the minuses for a couple of months. With the onset of spring, we have been having 20+ days.

Corrector plates are most commonly removed to gain acess to the mirror for cleaning. Anyone who's scope is out of warranty may have done this, as I have. It never even occurred to me to consider metal and glass contraction for the chance of seasons.

My windscreen on my car did the same thing to me a few years ago. A cold morning, turned on the demister and watched a crack go from one side of the car to the other in about 15 seconds....

It doesn't help that correctors are PAIRED with the primary mirror on manufacture. You cant just order a new one in the mail and chuck it in.
:sadeyes:
Now I know. Doesn't help me, but perhaps this warning can save others.

[Ian Robinson]

How are you going explain that the claims assessor when you make your accidential damage claim on the home insurance ?

Looks expensive to repair.

[Ric]

Geez Baz, as another "cat" owner that is a terrible thing to happen to your scope.

[RB]

I'm so sorry to hear that Barry.

:(

[Phil]

That sucks Baz. Sorry to see that mate.
Phil

[bloodhound31]

That's ok folks. I'm a bit upset, as I have grown quite attatched to this scope, but I will live I'm sure. Thanks for your condolences.



Ian, I am not sure if an AD claim would be legit but I am going to ask if it can be done. If not, it will have to be a personal loan I think. I think it is at the point where there is no point repairing. It will never be the same or up to standard again. It's time to replace.

Baz.

[peter brown]

My sceptic wife just said..."sounds like a very good excuse to buy a new telescope!! "

[Omaroo]

Sorry to hear about it Barry.

One thing that has always struck me, is the relative difference in quality between the Celestron and Meade SCT's I've had. Whereas the Meades use a very good quality metal corrector plate flange that distributes the tension of these bolts out along the flange very evenly over the corrector plate itself, the Celestrons use a flimsy crappy plastic flange - well, in the C8 anyhow. The tension under the bolt heads is very localised as the plasticdoesn't have the shear strength to distribute the load. What's the C11's made of? Looks like plastic to me? Maybe there's an aftermarket need for a better system?

Fuuny, huh. I've always thought of my Celestron's better optics (marginal, but nontheless true) but Meade's better tube quality.

[matt]

My C9.25 corrector 'flange' is metal.:)

[Garyh]

That`s terrible Baz,
have you checked to see if it still performs ok even with the crack?
Maybe you could get it repaired like a crack in a windscreen if the crack hasn`t distorted the corrector too much?

[bloodhound31]

Its a metal flange, but yes, it could be more solid to distribute the tension more evenly.

I havent looked through it yet, but the primary use of this scope is imaging. I have done extensive mods to this baby to squeeze as much as I can out of it. This cracked corrector is one giant optical leap backwards. Better to get a new one.:thumbsup:

[Lester]

Not good Baz.

If the scope is buggered and you cannot get a replacement corrector, then what Gary suggested with the windscreen fix type crack removal, is worth a try. If you don't try you will never know.

All the best.

[Satchmo]

Sorry to hear that Barry . You'll probably need to buy a whole new tube assembly. Meade don't individually figure their SCT optics to match each other. They use a mix and match process finding out which mass batch machine polished parts will work best with what. BY the time you send your whole tube back to match a corrector and wait X months, hence you'll probably find it simpler to buy a new tube.

[bloodhound31]

Heres a rough idea how a corrector plate is made (I think)

and how the image distorts when it cracks.

[Lester]

I would presume you would get bright flaring off of most stars, if not all stars.

I had a split many years ago in the prism of a off-axis guider that gave flaring off of the stars. I elliminated the faring by putting a black mask over the cracked area.

If you want the best, and no doubt you do, after seeing the work you have put into peltier cooling your scope; then get a new one. If finances are an issue, I would be trying these other things first.

[Ian Robinson]

Well .... it was the result of accidentially overtightening the screws , so as long as the report from who ever you send it to for inspection states ACCIDENTIALLY DAMAGED is the cause in their report and quote to repair then the insurance company has no option but to accept and either replace the optics or the entire telescope or send you a cheque.
Is perfectly legit to make a claim.
This is why you pay insurance.

[AlexN]

I agree with Ian on that... You dont pay for insurance for your gear only to not use it when something gets damaged....

As far as the legitimacy of the claim, I take it when you tightened the screws on the corrector you did not intend to damage it...

My condolences for your loss... I must admit I whimpered a little bit at seeing it... and thought of my C11

[leon]

I know that is no time to be jovial, :rolleyes: and I'm truly sorry that this happened Barry, but If the insurance company wont cover this, then get someone to knock it off, and claim theft coverage. :whistle: :doh:

Leon :thumbsup:

[bloodhound31]

:scared:Leon Leon Leon.....I am shocked beyond words that you could even think a good Christian boy like me could consider such deception......:rofl:

Baz.

No really.....

Baz.:P

[Ian Robinson]

Or "accidentially" drop said OTA down the back stairs or onto the concrete driveway :whistle:.... it's buggered anyway and then make the claim ....

Thieft claims are bad .... you'll be treated like you are a crook by the insurance company unless the police find evidence of an actual break in. Took me over 12 months to a settlement from GIO on my knicked 4"fluorite apo and GPDX. Needless to say I am no longer with GIO as I found the whole thing very insulting and distasteful .... having to get detailed phone records and explane every call I had made, and similar with every email ,despite the cops agreeing the garage had been broken into but was so dusty that no prints could be lifted , and hard to see how they got the door unlocked. and despite my having all my reciepts.

[bloodhound31]

Ian!:eyepop: Have you been mixing with Leon?

:rofl::lol::rofl:

Baz.:innocent::prey:

[JethroB76]

I reckon you could easily accidentally drop something like that..be careful when you're looking at it next, very round and slippery.:whistle:

[AlexN]

especially when its covered in dew and you're removing it from the mount

[Matty P]

Ouch! That is really painful to look at. :sadeyes:

I'm sorry to hear about this Baz. It must be a real bummer for this to happen now just as the weather is clearing up. It might be a good excuse to purchase a C14. ;)

What are you thinking of doing with it? Flogging it? :scared:

P.S. Just add a couple more cracks and you'll have diffraction spikes in your images. :lol:

[Jen]

:scared: oh no Baz that looks really sad :sadeyes: hope yo can get it fixed :doh:

[bloodhound31]

Thanks for you condolences all. We all know what a dear friend our telescopes can become. It has been my life for the past 7 years. I am sad to see it in such a state.

I still don't know what is to be done about it yet. I am waiting to hear back from Celestron about replacing the optics. I also rang my insurer to see if it was legitemately claimable. The other option is an upgrade.

I don't think I will buy the same scope again. Not even sure if I will buy an SCT again. a 12.5 to 16" RC could be the go. I will definately NOT get a fork mount ever again. Too many worm errors, gear wear and flex in the forks. Autoguiding has never worked with it because of this. Time for a good GE mount. EQ6 at a bare minimum.

[Ian Robinson]

We are all hanging in there for you and hoping it all works out costless or very low cost to get fixed or replaced.
Keep us posted on the verdic wrt the insurer .... you had nothing to loose by starting a claim , and everything to gain if they give you the nod.

I can't understand why people are so reluctant to claim on their insurance policies .... me .... I'll make a claim without hesitation if it looks claimable (ie more than the XCESS), just a matter of getting the right words on the report from the repairer (ie ACCIDENTIALLY DAMAGED) , that's what I pay insurance premiums for.

[CoombellKid]

Gee they actually came around to do finger printing!!!! when I had $4000.00
worth of tools taken from my garrage. All the cops would do was take a
report over the phone, refused to come around and look. Advising me to
see my insurance company... but wait a minute dont I need a police report
for that???? I dont bother calling the police these days, now that I have
sargent baseball bat. And since some years ago I a victom of a home
invassion in Sydney, stabbed nine times about the torso. I'll have a
reasonable excuse to half kill some on my property with a baseball bat.
And if they get away, well it's a long drive and only one road out of
Coombell and I have some mates that live at the start of it ;)

regards,CS

[Screwdriverone]

Bugger, Bugger, Bugger!

I would suggest talking to the manufacturer and seeing whether they can verify in writing if this is something that is possible to do accidentally and therefore back up your claim of the tightening of the screws/thermal expansion etc. Even a repair order/quote explaining what happened might be enough to justify to the insurance company that it is something that isnt listed in the manual and not something to be wary of in the normal wear and tear use of a telescope, certainly it seems its news to most of us here.

I had a tinkle tinkle crack issue with my secondary mirror on my newt as the instructions werent clear on how to correctly adjust the mirror position and the manufacturer explained that it was fairly common and they were changing the instructions to become less ambiguous. In this case ($20 mirror) they replaced it for free, but perhaps a bit of "mate, this is not something that should happend to a quality scope, and I am sure that you can understand the implications of design flaw, so can you help me out with a report for the insurance?"

Nothing wrong with this scenario, all truthful and above board and well within your consumer rights to request.

I hope you can get somewhere with this and it helps you get back to the skies soon.

Cheers

Chris

[bloodhound31]

There is nothing complicated or shady about a claim in this regard. Undoing a few screws to clean a corrector and mirror nullifies the warranty yes, but there has been no warranty on this scope for years. Warranty is not the issue here.

Taking off a corrector for cleaning is a NORMAL practice. Tightening up the screws on a retaining ring after cleaning is also NORMAL proceedure.

It doesn't take a genius to see that the crack originates directly in line with one of these screws. It is also very reasonable to deduct that as temperatures change, metal and glass expands and contracts and is most probably the cause of the crack.

So as you can see, there is no need, to "Accidentally" drop said OTA to make it "more" claimable.:lol:;)

[Ric]

Out of interest Baz, can the mirror be reused without the corrector plate in another scope.

You are a man of many talents, maybe you could design a tube with the correct length to the secondary to overcome the effect of the corrector.

Just a thought

[AstralTraveller]

No, but putting on a pair of steel-capped boots and kicking it around the back yard might make you feel a whole lot better. :lol:

[netwolf]

Can this be converted to a Cassegrain scope without need for the Corrector?
Thats assuming the Insurance company does not take it away.

Regards
Fahim

[CoombellKid]

I would be interested in seeing a couple of image results. Will a crack like
that make must difference to the overall result. Or would stars have a single
diffraction spike.

regards,CS

[bloodhound31]

I will see what I can do about getting a couple of exposures to show here.

I am not sure about using it without a corrector at a different length. I always assumed they were figured that way for a reason, otherwise it would be a Newtonian wouldn't it?

[Terry B]

It wouldn't even be a newtonian as it would have a fast big spherical mirror with terrible optical aberations.

[AlexN]

It wouldnt be a newtonian because the secondary bounces the image back to the rear cell...

I think it will suffer heaps of coma without the corrector, regardless of where you move the secondary to.

[Ian Robinson]

F/1 or F/2 aren't they ? Lensless schmidt is an option maybe ??? Just don't tell the insurance company that (they'll be looking for an out).


Sometimes see a 16" SCT primary for sale on Ebay , with a big cassegrain secondary sometimes too.

[AlexN]

the 11" is F/1.9 primary...

[kinetic]

Hi Barry,

So sorry mate, I can sort of understand, but my mistake wasn't as
big a blue as yours.

My 4" Bausch and Lomb SCT never was brilliant straight out of
the case and one year I decided to clean the corrector plate.
Back then I didn't realise that correctors and mirrors were a matched pair and even needed to be re-assembled so that the corrector sat
where it was on the clock face so to speak. IE corrector at 12 o'clock and
mirror at 12 o'clock.
There usually is a dot on the corrector to show where to sit it.
Stoopid me pulled it out, cleaned it and put it back oblivious to all
this.
Consequently the star images in this scope have never been close to
what it was before......and that wasn't all that great anyway :)

But you must have put some fairly substantial pressure on those screws
to crack a corrector, I would think?
I'd be reluctant to tighten it any tighter than say just past finger tight?
Any tighter would surely be the same as a pinched primary under a primary
clamp?

As others have said Baz, I'd be up-front, go through insurance and get
a probably substantially depreciated payout check.
Fight them if the fob you off. Their first reply will be to sell you way short.
Don't accept that.

Best of luck Baz,

regards,
Steve B.
Fellow Foam-Dome Owner :)