Making a Meade 2080 LX5 operational, help?
Posted 12 September 2021 - 04:14 PM
Posted 12 September 2021 - 04:38 PM
I got more evidence today that somebody has tinkered to an unknown depth with this scope at one time.
After I got the channel locks on the declination setting circles' mounting knobs I noticed that one side had significantly more "drag" when tightening than the other. Took the knobs completely off today and once side had a small washer between the setting circle and the fork arm while the other side did not.
You're right about the seeing, too. It has been 'poor' seeing the last several nights due to humidity and temperature. I sure had some examples of 'lucky seeing' where things would clear up for a brief second or so, then get worse, then clear up again. The primary mirror still has some greasy haze on it as well. When I originally removed the corrector plate I ran my finger and then a cleaning rag along the baffle to see how much grease was left. I nothing damp, and just a bit of black, dry, grease residue on my finger and the rag. The greasy residue on the primary didn't align with anything in the scope, being about 1/3 and 1/2 way out from the center. I figured that that was dead bug, but who knows?
I've got that grease coming this week. I plan to apply very, very little around the baffle with the mirror fully back and run it forward, then apply a similar amount and run it all the way back again to spread it. After that, another test, then start pulling the whole thing apart to fix the electronics and re-grease all of the mechanicals.
edit - I'm also missing the retaining ring / nut from one of the accessory plugs on the front, so that naked wiring behind the panel likes to *ahem* flop around unsecured. I've a small nut on it now, but it isn't the right thread. I imagine I'll be hitting up some fastener stores around here soon.
Edited by jamestheviewer, 12 September 2021 - 04:55 PM.
Posted 15 September 2021 - 10:11 AM
Grease and gloves, some extra tools, and some other stuff came in. I'll be getting back to work on this soon.
I found and failed to bookmark a message from orion61 on here where he gave his baffle tube lube mix (super lube and mobil 1 synthetic oil) and where he also said that (as I recall, it was for 2080s) the secondary orientation doesn't matter, but the corrector plate orientation does -and- I can't find it again. Google-foo, Bing-foo, nothing I try will find that message again. Anybody got the link that I forgot to save?
Posted 05 October 2021 - 11:41 PM
The 2080 coatings are super fragile. Silvered optics group had silvered secondary mirrors and having them start turning black and the need to re surface them is not unusual. They were identified not by the front ring on the corrector plate but by a placard on the back as either Multi-Coated Optical Group or Multi-Coated Silvered Optical Group.
I suggest Dr. Clay's (Arkansas Sky Observatory) formula and procedure for rinsing or washing optics, especially on these older telescopes. It's hard to say what's going on with your mirror haze at this point, but I'm hoping that it's deposited by the stuff you cleaned with and not chemical damage to the mirror. When it comes to SCT mirrors, cleaning is super problematic. But you probably know that by now.
Learned everything here
I have a 2080 that lived a life in the Southern California Desert and had been left with an open back cell. I did all the cleaning with the OTA on a GEM mount. Best holder ever!
I was able to clean it and get good performance. DId NOT wash or wet clean the mirrors assuming they were uncoated and that the multi-coated optics was referring basically to the corrector plate. Just dusted and drew the airborne dust out of the OTA with airflow from a vacuum.
With the corrector plate off, I tilted the OTA downwards and set the vacuum hose near the front to always have airflow drawing dust and debris away from the mirror. I cleaned out the inside of the scope with paint brushes and eventually cleaned the surface directly with wipes always avoiding any contact with the mirror. Finally dusted off the dust that had collected on the mirror with a hand blower to raise dust off the mirror and a bit of compressed air to free up a bit of more stuck sandy dust. The way to look at this process is to think very much about diminishing returns and increased risk on a logarithmic scale. Get the bulk of the cleaning that you can do safely done, and then STOP.. What's left that might get you 'just a little bit cleaner' is most likely connected with very high risk of damage and won't matter anyway. Even a small amount of damage to a mirror or coating is likely far worse than what you are trying to clean off. If it's a small spot on a mirror but it would require you to touch the mirror to get it off. Leave it alone. Trust me on this. You will create more disturbance of the mirror by trying to touch one tiny spot. then the spot itself creates..
Cleaned the corrector first by using the OTA tilted up and put on "backwards" secondary mirror facing out.. Then carefully reversed it and cleaned the outside surface. Had to do the inside only because the dust had turned to sticky dirt formed by the combination of dust and condensation.over time and there was a enough of it that dew formation was happening inside not just outside the scope.
Look for any tiny bit of white paint on the OTA, ring, cork spacer and edge of the corrector plate that might give you a clue as to what the original orientation might have been. As you suspect the telescope had been taken apart, the corrector plate orientation that you started with might not have been correct. These front corrector plates were hand figured to match the mirror so you may need to experiment yet further to get the best positioning.of the corrector. I suspect that's why you are still 'soft'.
Perhaps some advice from this group or the ATM group for how to get this aligned on a bench with a laser collimator or simulated star placed down the street used during the day may be easier than trying to do these experiments at night.
Even distilled water should be filtered through paper filters before use.
Yeah.. I know.. suppress the thoughts "that's crazy", but I yield to Dr. Clay's through testing of multiple cleaning methods and chemicals, and paper coffee filters are cheap compared to the time and frustration that getting streak free optics can bring.
Also, when he refers to Windex. It's the plain old plain blue Windex without ammonia or any kind of scent or acids. I had to go to a 99 cent store to find real "Windex" of the plain old style. I was able to source Kodak photo-flow off of Amazon. You only used a couple of drops, but it's just the right stuff to get the water to roll off the glass.
I found mixing cleaning liquids in really clean GLASS containers worked best for me. By really clean, meaning
rinsed and then rinsed in distilled and then perhaps rinsed in a bit of 98% isopropyl to get the water out and left to dry.dust free. I think the ASO site makes reference to sterilized droppers, etc. I mix a fresh batch, since it's not often that I've needed to do this and discard anything left in plastic spray bottles at the end.
The hardest things for me to find was -- plain Windex and Plain White Kleenex. Kim Wipes are probably easier to buy but quite pricey in comparison. I also wore gloves so that even handling a wipe my finger oil never gets on anything.
I don't know what it would cost to resurface a mirror these days and sind you say the coatings are damaged on the collector what it would cost to get this kind of repair done in an optics shop. I suspect though that you'd be better off buying an OTA that is of known quality and status rather than investing in this one. Do your best with it, and learn a lot in the process, but if it were me I would hesitate putting any serious money into it.
Clear skies and enjoy the process !!