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[-=CROMAN=-]

Hey all..

A buddy of mine asked me to help fix up his wifes fathers old sears refractor.

The Sears model is DISCOVERER Model No 3 - 4454

F 1200mm / D 80mm

The scope has been sitting around gathering dust in a basement since the owner pass away.

Aside from the usual lens cleaning is problem with the focuser. The focuser is so gummed up with old grease that it almost doesnt move. The focuser is also, i believe a .985 type.

Is it possible to purchase a a new 1.25" or 2" system for a scope this old?

[erikruud]

There are some threads on CloudyNights about these scopes. Apparently they were pretty good scopes.

There is a reccomendation in this thread to get a hybrid diagonal from ScopeTronics.
www.cloudynights.com/ubbarchive/showflat.php/Cat/0/Number/6736/page/0/view/collapsed/sb/5/o/all/fpart/all/vc/1

Otherwise, I am sure there are plenty of focuser options that could be adapted.

[erikruud]

I found the manual online.

geogdata.csun.edu/~voltaire/classics/sears/Sears_4454.pdf

[-=CROMAN=-]

Thanks Erik... good find. The scopetronix diagonal seems to have been discontinued. The search continues

[magic612]

I've fixed up some old Sears scopes (geez, I'd LOVE to have a 4454!!!), and the way to get rid of the gummed up grease - if you can really call it that - is to use a solvent. As I recall, I used denatured alcohol to get mine clean, but something like acetone might work too. WEAR GLOVES, obviously, and work slowly and carefully, especially the rack on the focuser tube. Let it sit in solvent and use an old toothbrush to clean up the teeth.

I know some people use white grease, but I've found that a touch of good quality automotive grease makes a good replacement. Careful with the lens - any mold or pitting? If that's in good shape, the scope should perform very well. I once had to take apart the eq mount of a Tasco 10-TE 72mm scope that was gummed up too - gotta be careful with the mounts, no replacement parts for them!

If you have any pictures, I can help if you need any. What a great scope! Should provide wonderful views when it's fixed up. Might want to use some better tripod legs though - that seems to be a weak point on most of those older scopes.

[-=CROMAN=-]

Magic.... The mount is completely mucked up from age,but it is not beyond a good cleaning. the tripod legs could stand a good murphys oil soap treatment as well.

As far as the lenses are concerned they look to be a b it moldy, not pitting though. I was hoping to find a replacement focuser for it but my searches have turned up nothing.

[magic612]

I think finding a replacement focuser for that is not going to yield much. That particular scope, though not what I would term "rare," is nevertheless not exactly floating around everywhere either. Back when it was made and sold, it was a fairly pricey scope.

If the mount can be cleaned, the focuser can too. They're usually pretty simple to disassemble, but if you run into trouble, let me know.

Lenses: Any mold is of concern. A good way to kill it without touching the lens is to take the lens cell off of the tube and let it sit in the sun for a day (obviously not where the sun can focus it into a hot point of light!). This will kill any mold on the glass without using cleaners or potentially scratching the lens with cloths.

There are a couple ways to use these older, .965" focusers and yield good results. One is to keep in mind that they are long focal length instruments; they will work well with the simpler eyepiece designs like Kellners and even Huygens or Ramsdens. I've even been surprised at the eye relief they provide on my older scopes. Another one is to do as Erik suggested, and get a hybrid diagonal - these can be harder to find, but they are out there. Then 1.25" eyepieces can be used in the older scope. And lastly, Antares sells some Plossls through HandsOnOptics.com that are .965" barrels, and they are not terribly expensive. So a better eyepiece design can be had for the smaller focuser. The field of view is going to be narrower, and I think the longest they offer is 25mm, but it's a decent option.

Hope that helps - please feel free to ask any questions. I've read and followed a lot of threads on CloudyNights about classic telescopes, so I should be able to help or at least guide you in the right direction.

And if he ever wants to sell it - please let me know first!!!

[erikruud]

Nov 8, 2011 11:40:49 GMT -6 -=CROMAN=- said:

Thanks Erik... good find. The scopetronix diagonal seems to have been discontinued. The search continues

Then how about ScopeStuff?

Or Antares?

[magic612]

Here's another other option:

www.agenaastro.com/antares-0-965-1-25-90-hybrid-mirror-star-diagonal.html

[-=CROMAN=-]

Thanks for all the information fellas. The mount has been de-gummed and lubricated and cleaned up. I also murphy oiled the wooden tripod legs. The overall condition is actually pretty good. I'm picking up the refractor today and plan on taking it apart tonight. I'll try to snap up some pics as I go along to post.

[-=CROMAN=-]

I've posted part of the story on iskywatch. Lots of pictures

elenin.paranomalo.us/sky-watching/restorations/sears-discoverer-3-model-4454/