5341 replies to this topic

[John Rogers]

I own the 3" REFLECTOR with constellations as shown in "A Guide to Astronomy" a Fawcett magazine from 1958.

Robert 

 

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That is so cool!  It is the only one that I have seen and am glad that it survived and is in good hands!

[apfever]

Ok, way cool.  Both of the above scopes have the same white finder with silver looking band on the front and no band where the slider goes in.  I know mine is Edmund but has an original band where the slider goes in. It came with a complete identical mount. I could take off the back band and paint it white. The finder performance is pathetic, so bad it made me smile. 

 

How does the long part that looks like a focuser extension work?  It looks like you have an eyepiece in it.  My tube fits in the focuser but won't take a .965" eyepiece. The tube mics at 1" O.D.,  0.92" I.D., with a 0.04" wall, all give or take a few thousandths.   Did these come with some sort of microscope eyepiece, or am I missing some adapter, or just missing it as usual?  I have no paperwork for this. 

 

Found it, sorta!   I'll leave the above inquiry for reference. The Edmund catalogs are elusive for eyepiece information on these. There are changes over the different 3" scope versions I mentioned above. Some were 1.25" normal. I did not find any mention of a .965" barrel on any of the ads. The 1977 catalog states that the "The Edmund 3" Reflector" (bottom line scope) takes a .917" barrel eyepiece. The OTA is PVC. 

Most of these ads with the smaller focuser have a small box on the same page that list accessories. The eyepieces listed are usually 1.25" with no further explanation. It's not just elusive but a bit topsy-turvy. 

Edited by apfever, 14 April 2025 - 07:21 PM.

[davidmcgo]

This was the version of the 3” reflector,I always wanted but never managed to get:

 

https://www.cloudyni...und-3-f10-newt/

 

Dave

[deSitter]

This was the version of the 3” reflector,I always wanted but never managed to get:

 

https://www.cloudyni...und-3-f10-newt/

 

Dave

 

I made one from parts as a side scope for my RV-6. It was surprisingly good! Its big moment was Venus and Mercury in the same 100x field of view. It was so light that rings were not required to mount it on the RV - just a threaded rod for up-down and a slide for left-right. Heavy cardboard tube. It was very low rent

 

-drl

[John Rogers]

The 3-inch reflector was first introduced in the 1955 catalog as a kit consisting of 87 pieces that a "nine-year old" could assemble.  It had a black tube and mirror cell that fit entirely within the tube.  By 1958, they were selling completely assembled telescopes, with a cap-style mirror cell at the back of the tube.  It came with a 1/2" focal length Ramsden eyepiece of .917" diameter and a barlow lens.  One could purchase optional 1/4" and 1" focal length eyepieces as accessories.

 

It should be noted that Edmund kept this telescope at the $30 price point for almost 20 years.  

 

[apfever]

These will be the last pictures here. I will be moving this to an existing Edmund string.

I lied. Since everybody has been sharing, here's the full set. From left to right: SC, DSC, SSC, 8".   The DSC, SSC, and mount for the 8 are all restored. The SC needs some cleaning and touch up, and the 8" needs minor OTA fixes. 

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[apfever]

Here's the other side. 

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[apfever]

The DSC and SSC have ever infiltrating dust and some lube creep from sitting (covered). These will still give an idea of where it's all going. The SC only needs cleaning and the secondary glued back on. I have no idea where I might find the .917 eyepieces. Technically these are all finds. I found them somewhere.  Oh nnnngh Gonk...I just got clocked (corrected). The SC found me. It was time. 

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[John Rogers]

The DSC and SSC have ever infiltrating dust and some lube creep from sitting (covered). These will still give an idea of where it's all going. The SC only needs cleaning and the secondary glued back on. I have no idea where I might find the .917 eyepieces. Technically these are all finds. I found them somewhere.  Oh nnnngh Gonk...I just got clocked (corrected). The SC found me. It was time. 

Nice display!  The .917 eyepieces show up from time to time.  They appear identical to their 1.25" Ramsden counterparts in a photograph.  If I spot one, I'll give you a heads up.

[deSitter]

The DSC and SSC have ever infiltrating dust and some lube creep from sitting (covered). These will still give an idea of where it's all going. The SC only needs cleaning and the secondary glued back on. I have no idea where I might find the .917 eyepieces. Technically these are all finds. I found them somewhere.  Oh nnnngh Gonk...I just got clocked (corrected). The SC found me. It was time. 

 

0.917 is 23.3mm which is very close to microscope standard, 23.2mm. Try it.

 

-drl

[deSitter]

The DSC and SSC have ever infiltrating dust and some lube creep from sitting (covered). These will still give an idea of where it's all going. The SC only needs cleaning and the secondary glued back on. I have no idea where I might find the .917 eyepieces. Technically these are all finds. I found them somewhere.  Oh nnnngh Gonk...I just got clocked (corrected). The SC found me. It was time. 

 

Here is a WF 10x eyepiece which translates to a 25mm eyepiece - probably Huygens design, might be Ramsden, both will be fine at f/10.

 

(Not sure what 18mm refers to here. In general Mag x F/L = 250mm. Might be the field stop diameter?)

 

https://amscope.com/products/ep10x23-s

 

-drl

Edited by deSitter, 15 April 2025 - 07:13 PM.

[clamchip]

The focuser is made up of a cast Bakelite body with a phenolic resin impregnated fiber tube measuring 2-1/2" long

29/32" inside diameter 1" OD with a small piece of felt to make the .917" microscope eyepieces a snug fit.

Robert

 

 

 

[apfever]

I do not need eyepieces. Thank you. All I needed was a trigger - again, but I never know that at the time.  The above link worked. The eyepieces in the link are the same as in my StereoZoom4. I use the Zoom every week. From there I remembered my microscope right behind me that I enjoy looking at Every Day. It is a large 1876 J. Swift bino microscope with the smaller eyepieces. Then I remembered a bunch of microscope eyepieces in a .965" junk parts box. Now I have a few eyepieces that fit perfectly and I don't have to steal anything from my microscopes.  I have already tried one and it fits the scope perfectly. 

[CHASLX200]

The focuser is made up of a cast Bakelite body with a phenolic resin impregnated fiber tube measuring 2-1/2" long

29/32" inside diameter 1" OD with a small piece of felt to make the .917" microscope eyepieces a snug fit.

Robert

 

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Never saw one like that.

[YourNotSirius]

The DSC and SSC have ever infiltrating dust and some lube creep from sitting (covered). These will still give an idea of where it's all going. The SC only needs cleaning and the secondary glued back on. I have no idea where I might find the .917 eyepieces. Technically these are all finds. I found them somewhere.  Oh nnnngh Gonk...I just got clocked (corrected). The SC found me. It was time. 

My old man has several 4-1/4" and 6" models. We also have at least one 8" model. I think he has the tripod/mount for one of the 3" models but not the OTA. I've seen a number of the original Edmund EPs in his pile of stuff, too.

 

He is keeping one of each in factory condition and then customizing the rest of them. He says there are enough to go around that are in original condition to last for centuries and he is going to start doing some "RESTOMOD" work on the rest. Very much like has been done with so many old cars. He says it's time to put some pizzazz into these things. So, here come the custom paint schemes and who knows what else!

 

FWIW

 

Q

[deSitter]

"(Not sure what 18mm refers to here. In general Mag x F/L = 250mm. Might be the field stop diameter?)" https://amscope.com/...ucts/ep10x23-s 

 

It does indeed refer to the field stop diameter - in microscope world that is called the field number. So to get the actual linear extent of a microscope view, you divide the field number by the magnification.

 

So, to move a microscope eyepiece to telescope land, you need to get the field of view from the field number N assumed to be in millimeters. And that is

 

AFOV = 2 arctan ( N / 2F )

 

From above,

 

F = 250mm / M

 

so

 

AFOV = 2 arctan ( N M / 500)

 

For the above eyepiece M = 10 and N = 18 so

 

AFOV = 2 arctan (9/25) = 40 degrees, which implies a Huygens eyepiece.

 

I directly measured the field stop of my WF16x eyepiece and came up with 14. AFOV=50 degrees. It's a Kellner. Focal length = 16mm. Nice telescope eyepiece, sharp black field stop.

 

Now my 5x eyepiece has a field stop that pretty much maxes out the 23mm barrel, 20mm internal. So AFOV = 23 paltry degrees - it's Huygens so no biggie. This translates to a focal length of 50mm as mentioned before. Still useful in a long classic refractor because it gives a 3mm to 4mm exit pupil depending on the classic - 5mm at f/10.

 

-drl

[apfever]

I know all that math, but no need too. Thank you so much for the link in entry #5336 that triggered my thinking.  I put them in and they work, that is all that's needed for the toy side of the series. Functionality trumps, looking cool next, tech specs is last. They are a text book fit with no shimming to hold in upside down. I'm still finding more microscope ep parts and adapters now. I will eventually get very close to the original e.p. if not find an original.

 

My old man has several 4-1/4" and 6" models. We also have at least one 8" model. I think he has the tripod/mount for one of the 3" models but not the OTA. I've seen a number of the original Edmund EPs in his pile of stuff, too.

 

He is keeping one of each in factory condition and then customizing the rest of them. He says there are enough to go around that are in original condition to last for centuries and he is going to start doing some "RESTOMOD" work on the rest. Very much like has been done with so many old cars. He says it's time to put some pizzazz into these things. So, here come the custom paint schemes and who knows what else!

 

FWIW

 

Q

I'm going to be asking about paint help on the SC OTA. The original white wrap won't clean up and I'm not satisfied with the appearance. I'll be checking in with scheduled help at Hobby Lobby with an experienced person on the original white wrap and what they have. 

 

Enough on this in this string. It is imposing on "Finds".  Go to the Edmund Space Conqueror Rebuild.