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The Ohio "$10" Edmund 4" f/15 from Facebook

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#51 photiost

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Posted 04 July 2020 - 12:38 PM

Yours is similar to this Rank designed Red Edmund 4in with EQ mount.

 

These telescopes have Excellent objectives.

 

You will be amazed !!

.

 

 

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  • Edmund 4in f15 Rank designed.jpg

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#52 Kasmos

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Posted 04 July 2020 - 01:32 PM

I made a 105mm/F15 using an objective I bought in CN Classifieds for $100. It came in an Aluminium Cell. Here is a picture of my build. You can see the exposed Al cell at the top. Could this be the same Edmunds objective? 

 

I see now that the original you have appears to have a different cell. So either mine is a different one altogether or the cell could have been replaced by the previous owner. The lenses are in superb shape.

It's hard to tell from the photo but the two ridges on the cell makes it look like a Jaegers. They are usually anodized black but it might have be stripped to bare aluminum. A close up photo of the cell would help. Maybe you can post one in Miscellany or it's own thread?

 

Back On Topic: Nice find.

I don't see any issues that will hamper it's use. It looks like all you need to do is find a nut and bolt and some clean up.



#53 Bomber Bob

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Posted 04 July 2020 - 01:51 PM

Bob, Wow!  Congratulations!!  What a great score on a fantabulous 4" refractor.

 

When spread out, that big tripod lets you swing that long scope with ease.  Ah!  And The Views...



#54 Terra Nova

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Posted 04 July 2020 - 01:57 PM

Bob, Wow!  Congratulations!!  What a great score on a fantabulous 4" refractor.

 

When spread out, that big tripod lets you swing that long scope with ease.  Ah!  And The Views...

And that from yet another former 4" F15 Edmund refractor owner! 



#55 ryanr256

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Posted 04 July 2020 - 09:42 PM

I spent some time today cleaning everything. I won't bore you with photos of a clean counterweight, tube or eyepieces. They did clean up very, very well.

 

I will, however, post some pics of the objective. It came out a lot better than I expected. Lots of lens cleaner and cotton balls were used to get it looking like this:

 

20200704_175652_small.jpg

 

-Bob


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#56 ryanr256

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Posted 04 July 2020 - 09:42 PM

20200704_175659_small.jpg


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#57 ryanr256

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Posted 04 July 2020 - 09:44 PM

The imperfection I mentioned previously is still there. It looks to be between the elements, but I am not going to risk taking the lenses out of the cell to find out what it is. It's small enough that it isn't going to affect the view.

 

20200704_175713_small.jpg


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#58 ryanr256

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Posted 04 July 2020 - 09:45 PM

Here it is all set up and ready for Jupiter:

 

20200704_202016_small.jpg


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#59 ryanr256

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Posted 04 July 2020 - 09:46 PM

Different angle:

 

20200704_202054_small.jpg


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#60 ryanr256

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Posted 04 July 2020 - 09:52 PM

Now I need to research how things work with this mount. I have book marked several CN threads that have information on this model.

 

I do have one question:

 

How is the diagonal held in the focuser tube? Is it held by friction? I see there's a small hole at the bottom of the focuser tube but none of the thumb screws I have in my stash are small enough to thread into it.

 

Also, I need to get a shower cap to keep the dust off of the lens.

 

Oh, I did plug the clock drive in. The smoke stayed in and there was no excitement, which is good. I'll do some reading and learn how things operate with this mount.

 

-Bob


Edited by ryanr256, 04 July 2020 - 11:06 PM.


#61 davidmcgo

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Posted 05 July 2020 - 12:06 AM

It was a really tiny screw to hold the diagonal, either a #6-32 or a #4-40.

 

Dave



#62 ryanr256

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Posted 05 July 2020 - 07:07 AM

It was a really tiny screw to hold the diagonal, either a #6-32 or a #4-40.

 

Dave

 

Thanks. I discovered that it's the same as the ones holding the dew shield on.

 

-Bob



#63 CaptKirk

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Posted 05 July 2020 - 08:54 PM

Your lens could be an Edmund, or it could be a Jaegers. Several years ago I built a 103mm f/15 refractor from a Jaegers lens purchased from Surplus Shed.


It wasn't $10. The asking price was $50. I paid more than asking because I am aware of the value. It's not in pristine condition and the price I paid reflected that. At the end of the day, both the buyer and seller were happy with the exchange.


And, the credit for the find goes to jragsdale. I just drove there to get it. ;)


-Bob



#64 CaptKirk

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Posted 05 July 2020 - 08:55 PM

For $50 I would’ve jumped on it.

#65 ryanr256

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Posted 06 July 2020 - 09:56 AM

Interesting situation:

The 'scope didn't have the set screw for the diagonal. In one of the archived thread on CN about this OTA, I came across an image of the focuser and the thumbscrew in the image looked like one of the dew shield screws.

Sure enough, a dew shield screw threads into the hole in the focuser tube. But, when I slide the diagonal in the screw doesn't catch and doesn't thread into the hole.

OK, no biggie, I have some taps and thumb screws. I drill and tap another hole (!) on the opposite side on the tube from the original hole but have the same situation. A screw will thread in no problem without the diagonal in place but when the diagonal is in the tube, the screw won't catch and thread into the hole.

-Bob

#66 zjc26138

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Posted 06 July 2020 - 01:50 PM

Congrats on a great find!

 

Wish I would have seen this sooner, I don't live terribly far from Canton.



#67 danielgolite

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Posted 06 July 2020 - 08:29 PM

    Nice scope! Thanks for posting your story. Please share how the views through it are. I believe Dave Trott made a You Tube video on this scope.



#68 davidmcgo

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Posted 06 July 2020 - 09:43 PM

You may need to grind the tip of the screw to a really flat point with no taper.  Have a nut on it first to run off and clean the threads.

 

Dave



#69 ryanr256

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Posted 06 July 2020 - 10:15 PM

    Nice scope! Thanks for posting your story. Please share how the views through it are. I believe Dave Trott made a You Tube video on this scope.

 

Thanks! We are in our Summer heat/humidity/thunderstorm phase at the moment. It may be a week or two before I get stable enough skies to see its potential. I'm currently working on the mount, doing some of the suggestions in the excellent thread:

 

https://www.cloudyni...mount-overview/

 

 

You may need to grind the tip of the screw to a really flat point with no taper.  Have a nut on it first to run off and clean the threads.

 

Dave

 

I probably shouldn't admit this, but I ran an M3 tap into the original hole. It cut new threads that look very clean. I picked up a few M3 cap screws from Home Depot tonight during my shift and just tried one of them. It works. And, now I have a hole on top where it can remind me to think a little more before acting. smile.gif

 

I think part of my issue was that the the threads in hole of focuser tube were damaged and the screw was catching the very end of them. In essence, there were no threads in the hole until almost the very end. The M3 tap cut strong threads all the way through.

 

I have some knobs on order for the RA and Dec tension. While I wait for them I am going through the mount, and with amicus' and apfever's help, trying to fix some of the design issues. The shafts are gouged pretty good from the tension bolts. I am in the process of cleaning them up. 

 

-Bob


Edited by ryanr256, 06 July 2020 - 10:58 PM.

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#70 jragsdale

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Posted 07 July 2020 - 07:03 PM

Awesome! Glad you got it, I knew that was a winner when I saw the ad.



#71 ryanr256

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Posted 07 July 2020 - 09:51 PM

Awesome! Glad you got it, I knew that was a winner when I saw the ad.

 

Yes, thanks for posting the ad. The optics are near perfect and the mount is disassembled, waiting for shims, knobs, etc. as referenced in the mount overview thread.

 

I've been debating on shimming the worm, but I may as well do it since I have the mount completely taken apart for the other mods.

 

I do wish I would have asked who the owner was. I've wondered if he was a member here.

 

-Bob


Edited by ryanr256, 07 July 2020 - 09:51 PM.

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#72 ryanr256

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Posted 10 July 2020 - 01:52 PM

OK, at first I wasn't going to into deep detail on refurbishing this telescope. But, my OCD got the best of me, so I decided to go through the mount and make the modifications mentioned in a thread referenced in an earlier post. So far so good. I ordered some shims, spacers and knobs.

 

While I'm waiting for those to arrive, I looked at the finder again. I've previously cleaned the lenses and saw this:

 

20200708_130226_small.jpg

 

 

Ugh.

 

-Bob



#73 ryanr256

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Posted 10 July 2020 - 01:56 PM

But, no worries. One of the great things about this website is that there is all kinds of information available on all kinds of topics. I found this thread:

 

https://www.cloudyni...ope-crosshairs/

 

and in Post #17 I saw a pretty neat idea on how to align the crosshairs. Also, as luck would have it, my wife has a spool of "Invisible thread" available for my use. Yay!

 

Here's my jig:

 

20200709_141211_small.jpg

 

Ignore the lines drawn on the cardboard. The thread didn't stay stuck to the mounting tape on my first attempt, so I stuck a small piece of tape on top. That held everything well. I then used the tip of a pin to apply some super glue to hold the thread.

 

-Bob


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#74 ryanr256

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Posted 10 July 2020 - 01:58 PM

This is what is looks like through the finder:

 

20200710_141529_small.jpg

 

I think the Invisible thread is of a smaller diameter than the original copper wires.

 

In the meantime, I received the shims and spacers. The work on the mount will now commence.

 

-Bob


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#75 ryanr256

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Posted 13 July 2020 - 09:33 PM

Polar aligned and ready for first light on July 12th:

 

20200712_223816_small.jpg

 

Unfortunately, the humidity was extremely high. I did take a look at Jupiter and Saturn but everything was covered in dew and the planets were not very high in the sky. Not good conditions to evaluate a 'scope or eyepieces (I have the 28mm, 15mm and 8mm RKE).

 

-Bob


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