Helping my school with a telescope, advice appreciated

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Discussion Overview

The discussion revolves around the restoration and usability of a 12.5 inch Newtonian telescope at a local high school, as well as an antique brass telescope. Participants share advice, experiences, and inquiries related to the maintenance and potential historical significance of the equipment.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Historical

Main Points Raised

  • Old Jim describes the condition of the 12.5 inch Newtonian telescope and outlines his plans for maintenance, including fixing motors, cleaning, and aligning the mount.
  • He inquires whether to remove the main mirror and diagonal for cleaning and what type of lubricant to use on the eyepiece rack and mount drive gears.
  • Some participants express excitement and offer encouragement, while others suggest resources for further assistance.
  • Discussion about the antique brass telescope includes speculation about its origins and potential historical value, with references to the Antique Telescope Society and historical figures in telescope manufacturing.
  • Old Jim reports progress on the restoration, including cleaning a smaller finder scope and addressing issues with broken mounting bolts.
  • Concerns are raised about the condition of the main mirror and the need for careful cleaning, with references to a specific cleaning product recommended for its coating.
  • One participant suggests that the mirrors may need recoating due to long-term disuse but notes that minor scratches may not significantly affect performance.

Areas of Agreement / Disagreement

Participants generally agree on the excitement of restoring the telescope and the historical interest in the antique piece. However, there are differing opinions on the necessity of cleaning and recoating the mirrors, as well as the best practices for maintenance.

Contextual Notes

There are unresolved questions regarding the appropriate cleaning methods and products for the telescope mirrors, as well as the historical significance of the antique telescope. Participants express varying levels of expertise and knowledge about telescope maintenance.

Who May Find This Useful

Individuals interested in astronomy, telescope restoration, and historical optics may find this discussion valuable.

jim hardy
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My local high school has a telescope that has sat unused for at least a decade.

I play poker with the principal and have an opportunity to assist getting it back into usability.

Visited it this morning
doesn't appear to need much
it's a 12.5 inch Newtonian in about six foot tube on equatorial mount with clock drive
in a domed silo adjacent the school
mirror looks good - fortunately it was parked pointing down so hasn't accumulated dust
I replaced the dust cover

the motorized observatory dome rotates okay but vertical door doesn't move - probably a simple electrical problem i'll look at early tomorrow morning before it gets too hot in there

A box with probably a dozen expensive looking Meade 2" eyepieces (one is a 40mm ultra wide angle with a glass lens probably a full inch across) and a camera adapter but no camera,
and a solar filter

So my immediate questions are

I just plan to fix and lube motors for door and dome,

brush out the dust in tube

inspect clock drive, clean it and the drive gears on mount
align mount for our latitude
see if I can find Saturn one evening next week

Any pointers?
Would you guys remove the main mirror and diagonal before dusting out the tube? I'm inclined to
I muddled through an alignment on my 4" can probably stumble through this "Real" 'scope
right now I do see my eye smack dab in middle when sight down focuser with no eyepiece so she's not bad now...

Would you guys lube the eyepiece rack&pinion? With what - silicone grease , plain grease, Vaseline,,,,, I'm afraid of vapors getting on the optics is that a worry ? Same for mount drive gears ??

I guess you can tell I'm excited...

Pointers to a guiding article would be appreciated.
I guess i'll re-up subscription to Sky and Telescope...

Also in the basement is an ancient looking brass telescope perhaps 4 feet long
with name engraved in script
F Fritsch
K K Hof Universtats Optiks
Wien Alserstrasse 17
it sits on a solid brass equatorial mount with brass reduction gears & handwheels
sadly the kids have swiped the eyepieces
I quick google turned up nothing on it - is it familiar to anyone?

Anyhow - please wish me luck. I feel like this is an opportunity to learn a lot more about an old hobby, with a very nice piece of equipment.

Pointers to informative articles at low but not quite zero expertise level would be appreciated.

Thanks,

old jim
 
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Good luck Jim! This sounds like a great adventure. Wish I could help you with advice, but I'll leave that to the astronomy pros...
 
That old scope sounds very interesting, you may want to see if the people at the Antique telescope society can be of more assistance in figuring out that mystery. From what I was able to look up that would simply appear to be the address of the owner who worked at the optics university in Vienna. More interesting is the name, Fritsch, there were some gents in Austria in the late 1800s making scopes of various sizes, my knowledge on the subject is pretty much Google (nil) but I did find some possible leads. I found a picture that may or may not be related. If it is real it probably belongs in a museum. The address indicates the Optics school in the University of Vienna. The KK Hof seems to be some sort of exporter licensing. These links assume I am on the right track.

http://commons.wikimedia.org/wiki/File:Jirasko_telescope_2892.JPG

On KK Hof (google translated):
http://translate.google.com/translate?hl=en&sl=de&u=http://de.wikipedia.org/wiki/K.u.k._Hoflieferant&prev=/search%3Fq%3DKK%2BHof%26client%3Dfirefox-a%26hs%3DTqq%26rls%3Dorg.mozilla:en-US:official

Antique scopes:
http://webari.com/oldscope/

Good luck!
 
Last edited:
Thanks guys

dome and door working now. One needs that ventilation this time of year.

I took apart and cleaned the little 2" refractor (pre?)finder

and am working now on the the 4" reflector finder .
Somebody before me has scratched the mirror. But a wash and distilled water rinse (per the Sky & Telescope article ) has it I think quite useable. Mud dauber wasps had built in the tube and somebody before me removed the worst of it but far from all . I suspect that's when the mirror got scratched.
All four diagonal-spider to tube mounting bolts are broken, it was held in place by good fortune. Will fashion a fix, probably just make new ones .

I didn't do anything with main 'scope beyond lookiing so far.
Main 12" mirror looks good from peering down the tube. Fortunately the mud-daubers didn't build in there like they did in the finder. It has a sticker on back says it's coated with a hard coating called "Beral" to facilitate cleaning and recommends a product called "MIR O LEN " with a name Clausing of Skokie Il. I hope he's still in business.. I will approach that task, if it is necessary, with great caution. Hopefully it'll be okay as is.


Thanks for the interest , fellows.

That Fritsch telescope is I believe authentic, Thanks for the links. It's on a cast iron pedestal weighing a couple hundred pounds. The mount looks to be missing a few worm gears, but the big brass wheels and gears are a sight to make a home shop machinist's day. I doubt we'll do much with it.

old jim
 
jim hardy said:
I didn't do anything with main 'scope beyond lookiing so far.
Main 12" mirror looks good from peering down the tube. Fortunately the mud-daubers didn't build in there like they did in the finder. It has a sticker on back says it's coated with a hard coating called "Beral" to facilitate cleaning and recommends a product called "MIR O LEN " with a name Clausing of Skokie Il. I hope he's still in business.. I will approach that task, if it is necessary, with great caution. Hopefully it'll be okay as is.

old jim


If not hopefully you can pull enough details on those product via data sheets, WHMMIS or alternate resource to infer their applications. Unfortunately I can't help much in this thread other than as a fellow technical industry jack of all trades tech. Much like you are from what I've seen on the engineering forums.
 
The mirrors may need recoated after sitting idle for such a long time. I would not worry about an isolated scratch or two. They will have negligible effect on performance if simply ignored. Apparently this scope is designed for wide field views. The best performing eyepieces should be in the 25mm plus range.
 

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