A stream of "something" inside the OTA
Posted 17 May 2009 - 08:01 PM
As I was setting my scope up for viewing tonight I noticed that I have a stream of "something" inside the bottom of the OTA. Not sure if it is grease or oil but it is just a tad disconcerting . It does not appear to be runny but there is a bit of a sheen to it - cannot determine where it is coming from. I have read previous posts of folks who have taken off the front corrector plate and as a person who has been a little to timid to even install the Bob's knobs that I purchased, that seems a little daunting. I have always kept my scope in th down position when storing (as when it is shipped), covered with the heavy-duty Tele-gizmo cover in the garage. Any ideas of remedies, causes and is this severe enough that I should do something (as in taking of the corrector plate to clean it up)?
Below is a picture of the inner OTA - hopefully you can see the little stream of wetness.
Thanks and clear skies,
Posted 17 May 2009 - 11:39 PM
think i somehow got some in my ota once
took the diagonal and adapter off, pointed the thing up
and a little trickle ran out
might leave the scope in a dry place with the diagonal etc removed and the end opened to allow evaporation
but a covering to keep dust out
Posted 18 May 2009 - 12:59 AM
I would consider getting a closer look inside. My tube had a huge glob of lube on the side right behind the mirror. It was not running like yours but I suspect it could have. As it was serving no purpose I removed it.
Check this forum about 6-9 months back. There were several posts with a similar condition.
BTW - I store my scope pointing down with a Telegizmo in the garage as well. Unless your garage gets up in the 100s during the day you're fine.
Posted 18 May 2009 - 06:16 AM
Someone in a previous post said they talked to Celestron who recommended storing it horizontally.
Posted 18 May 2009 - 10:54 AM
Posted 18 May 2009 - 11:23 PM
If you want to totally cure the problem, point the OTA slightly up, extend the mirror all the way (focuser knob CCW), remove the snap ring at the end of the baffle tube (Carefully!), and slide the mirror off the tube, rotate it sideways, and extract through the notches on the front cap.
Then clean the baffle tube and the mirror mount tube with mineral spirits, re-lube with Super Lube General Purpose grease, and reassemble.
Posted 19 May 2009 - 02:29 AM
Posted 19 May 2009 - 07:29 AM
Welcome to the lube running club.
Clean it off, and don't store it corrector down.
Don't bother calling Celestron.
Posted 19 May 2009 - 11:58 AM
Hard to figure why some folks do have the problem and others don't
Posted 19 May 2009 - 07:09 PM
Anyway, I did contact Celestron and they did send me an RMA. After reading some previous posts on cloudynights regarding this issue, I decided to clean the inside of the tube rather risk shipping it back (even though it was still under warranty).
Since then I haven't had the issue re-appear, but I have stored the tube horizontal only. I suppose one day soon I'll re-grease.
Posted 19 May 2009 - 07:11 PM
Thanks for all the replies - I appreciate it. I guess I am going to first start parking my scope in a more horizontal (or 45ish degree) position. I imagine that sooner rather than later I will take the front corrector plate off, there are nice directions with pictures here. Is there any particular substance I should use to clean off the grease, and while I am at it, any particular product that I should use to wipe down the secondary mirror and front corrector glass plate?
Thanks and clear skies,
Posted 20 May 2009 - 05:44 PM
That will be a bit more of a challenge to clean.
You can use windex on your corrector, but see the numerous threads on corrector cleaning before you begin. Seriously, you don't want to scratch it.
Posted 20 May 2009 - 09:02 PM
No, it all appears to be on the inside bottom of the OTA. I also have taken the visual back off and looked inside and that area looks to be clean. The corrector plate has nothing on it but it just looks a tad dusty and I figured when I have it off, it probably is a good time to give it a bit of a cleaning. I will do a search on cleaning the corrector though, because as you said, I do NOT want to scratch it!
Posted 21 May 2009 - 06:14 AM
I use his technique and cleaning solutions and have had very good results. Many here on Cloudy Nights recommend it. Technique is as important as the solutions you use. I know some people, including Uncle Rod, say that using Windex directly will not cause a problem, but to err on the side of caution I'd use Dr. Clay's solutions. Just my opinion.
Posted 21 May 2009 - 06:59 AM
Thanks for the link. After reading Dr. Clay's discussion on cleaning I realize that, other than wiping the grease from the bottom of the OTA (anything special I need to use to do that?), I really only need to remove dust from the corrector as there are no streaks or caked on debris. So, I will follow his instructions on using a brush to lightly wipe away the dust (when I gather enough courage to take the front corrector off ).
Thanks again and clear skies,
Posted 21 May 2009 - 07:06 AM
A puff or two with a rocket (large capacity bulb) blower is probably all that's needed. A small amount of dust will have no effect on the optical performace.
I will follow his instructions on using a brush to lightly wipe away the dust
Posted 21 May 2009 - 06:14 PM
I cleaned up my tube oil streak with just a lightly damp paper towel, dabbed up the moisture with another dry one, and let air dry before putting the corrector back. There is still a faint mark where the streak used to be, but you need to look hard to find it.
Of course I was lucky as my optics were untouched by the grease.
Posted 21 May 2009 - 07:28 PM
The slide/pics were very informative for marking the spacers and removing the corrector. Someday soon I'll get the nerve to try this technique...
Best of luck to all the club members that do give it a go.......
Posted 21 May 2009 - 10:28 PM
Posted 22 May 2009 - 07:31 AM
I have always stored my OTA horizontal. But even still, if the scope has been sitting unused for a month or so I will take a minute or two to run the focuser stop to stop several times. My thinking is that it helps to redistribute the grease and possibly mix it up a little to keep it from seperating and dripping. Now I don't even know if the focuser/baffle tube is where the offending grease is coming from, but so far I haven't had any dripping grease. Could also just be dumb luck though.
Posted 23 May 2009 - 12:09 AM
Posted 23 May 2009 - 10:09 AM