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.
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?
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.
Now I know. Doesn't help me, but perhaps this warning can save others.
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.
Quote:
Originally Posted by 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.
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.
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.
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?
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.
Quote:
Originally Posted by 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?
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.
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.
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.
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.
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.
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.
Last edited by Ian Robinson; 01-10-2008 at 11:41 AM.
I know that is no time to be jovial, 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.
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. 
