Oil leak in CPC 925

[johnnyt123]

Hi

I have a Celestron CPC 925 gps which I bought second hand about 2 years ago.

Things were working ok until one night I noticed that the view wasn't as sharpmasmit used to be and I couldn't quite get good focus.
I examined the scope and noticed that there were several oil drops son the secondary mirror that rad ran off the baffle tube.

Does anyone know whynthismhas occurred and how to fix it? Is there a professional place I could send it to,for cleaning and repair.

Any information would be greatly appreciated.

Thanks ....

Johnny

[Allan_L]

Hi Johnny,

Sorry to hear you have equipment woes.
I have heard of this happening before, with several other CPC machines.
Apparently due to an incorrect (or faulty?) oil type used in production.

I recommend you contact Bintel, who may be able to advise the best course of action. (see advertising link on right)

Is the scope still under warranty?

[gb_astro]

One of our Pony Club members had this problem with an out of warranty CPC1100.
Going through Bintel I am pretty sure they had to send it back to Celestron in the USA for cleaning.
His user name on this forum is Bones.
Look him up on the Members List and send him a PM about it.

It is possible to clean it yourself if you are feeling brave and do a bit of research.

gb.

[johnnyt123]

hi Allan..

I spoke to Bintel and they said they can clean it but wont be able to replace the oil used. they also gave no guarantee that the secondary mirror wont be scratched or have the coatings damaged....

So that really doesnt solve the problem but only a temporary patch job.

The scope is no longer under warranty.
It was purchased brand new 4 years ago. Plus i dont have the original receipts.

I have emailed Celestron in the States but have yet to hear from them....

Will see what happens...

I was thinking of doing it myself....but worried i might ruin the delicate optics...

[Allan_L]

That would be a last option... If Bintel (who are experts) can't guarantee no damage, then there is no way I would even try it.

As gb said, contact "bones" I know him and he will set you straight on your best option.

As to warranty, I thought Celestron scopes were warrantied for 5 years?
Do you know where the previous owner bought it from?
This may be worth following up.

[johnnyt123]

it would be impossible chasing up the previous owner,

I didnt ask where or how long he had the scope before selling it to me.
He didnt supply me with any receipts......
I bought it from ebay 2 years ago.....

I still havent heard back from Celestron either....


i dont know what to do....

Maybe just clean it out and replace the defective grease and if i need to then replace the secondary mirror for a new one....

[multiweb]

All you need to do is remove the corrector assembly then the secondary from its cell and wipe everything with acetone. Also wipe the excess grease from the baffle. Maybe you stored your CPC upright facing down.

It's a no brainer really. Just a few things to be aware of.

1_ Note the orientation of the corrector and which side is facing out. Just take a pic of the shims so you know where they go.

2_ Take a note of the orientation of the secondary inside the corrector. There's usually a line at the back that should point at 3 o'clock facing the scope.

That's all there is to it. Don't stress. Any doubt PM me. I'm not far from you. Liverpool just down the road.

[gb_astro]

Did Bintel say why they would not replace the internal grease?

There is not much point in just cleaning the secondary/corrector since it is likely to just happen again.

gb.

[johnnyt123]

Hi Mark. Thanks for that Valuable information.

I was considering using an alcohol based solvent to dissolve the grease but u suggest acetone. I believe acetone is a more powerful solvent.

What would you suggest to replace the existing grease with. Is there a thicker higher density grease that I can use?

Thanks again.

[johnnyt123]

Hi gb

Bintel weren't keen on doing the procedure but would do it. They said they wouldn't be liable for any damage that may occur. Now that wasn't very comforting.

They suggested I contact celestron first. And I have done so and am still awaiting their response.

If I don't hear from them. I might just take it to bintel and we will see what
Happens.

But I don't see how difficult it would be. Just need to replace all the parts back into the exact position they were before I take it apart.

[gb_astro]

There was plenty of discussion about this issue over at Cloudy Nights SCT forum a few years ago. I have not checked lately.

http://www.cloudynights.com/ubbthreads/postlist.php/Cat/0/Board/nexstargps

One of the greases recommended was this one:

http://www.amazon.com/Synthetic-Grease-Syncolon-Purpose-Lubricant/dp/B000XBH9HI

It's pretty disgraceful that Celestron did not do a product recall over this.

gb.

[Capricorn1(Tom)]

See video instruction on starizona.com web site to to remove the corrector lens.:)

[The_bluester]

That would be the most common way to store them, I do that too. The design of the CPC mount means the natural way to store them is with the corrector pointed straight down in between the fork arms. I might start storing mine in a different position.

[multiweb]

I used to as well when traveling especially. But I did get grease drops on the inside of the corrector and figured facing down is not ideal.

[multiweb]

Alcohol is fine too. If you remove the whole secondary just deep it inside water with a little dish washing liquid drop and rince it out. Just wash it with you fingers. You're not going to scratch anything with your skin. Then rince it out. Don't let the grease in for too long or it may get inside your coating depending on its chemical composition.

Get a grease that doesn't fall apart at low or high temperature. Something sticky like a moly paste. That will minimise mirror flop too if any.

You don't need to put much. There is a depression in the central baffle (couple of thous) that acts as a grease trap. All excess will be shaved and pushed in the back cell.

[johnnyt123]

Multiweb, Paul and gb_astro....

Thanks for all your help guys, it isn't a design flaw with the cpc it's just that once they started making them in china they had a bad batch with inferior grease and mine happened to be from that batch. The grease liquifies at higher temps and I had the scope stored in the garage the week before I noticed the poor image quality due to grease on the secondary mirror. We got a couple of hot days back then.

I managed to contact bintel again and I spoke to a gentleman called Don who said he would be able to perform the clean and grease replacement for a nominal fee. It would take 2-3hrs work and would cost $160-$240

Which I think is fair considering I can't use the scope satisfactorily at the moment.

I will be dropping off the scope on sat the 8th.
Hopefully the weather would have cleared up by then.

Thanks guys....


Johnny

[mbaddah]

Hi Johnny,

If my memory serves me right Don used to work for Celestron in the past? I'm sure you'll be in good hands. Hopefully the issue gets resolved.

[multiweb]

I don't think he worked there but I know he went to Celestron in the US for training while at Bintel.

[johnnyt123]

Hi Guys.....

Just picked up my CPC 925 from Bintel in Sydney and it looks like Don did a really good job servicing it and cleaning up the oil that was on my secondary mirror.
He also replaced the grease and collimated the scope once everything was cleaned.

total time spent servicing the scope was 2hrs and 30min approx.
And total charge was $200 which i thought was fair.

Here are some pics of the secondary before it was cleaned.
Now it is like new......

Take care...

[brian nordstrom]

:D Good news , and great service . Yes Bintel do , do a good job .
$200 is awsome .
Clear skies Johnny.
Brian.

[allan gould]

There is an expression going around. "Don is GOOD"
No it's " Don is excellent"

[LewisM]

In all my dealings with Bintel, Don has been super.

[Shano592]

Don is certainly the guy to go to, for these types of issues.

[johnnyt123]

I am yet to take it for a test run but when I do I will come back and give you my final thoughts .....