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Vintage Reflector OTA - Commercial or Homemade?

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126 replies to this topic

#101 Sean Cunneen

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Posted 21 April 2021 - 11:24 AM

Wow! Fantastic posts... I have to admit that the ad was posted the day before I was to drive from Chicago down to Charleston Illinois. It just so happened that I would pass 72 which went down to Lawrence Kansas and it took every ounce of willpower I had not to make the turn on 72 and keep going so that I could pick up the scope myself! seeing you do this tear down reassures me that the scope went to the right person!
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#102 starman876

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Posted 22 April 2021 - 07:04 AM

Last one for tonight, I'm off for a Long Island late happy hour.

 

This is the purple X in the long shaft. It is a 5th worm assembly that allows rotation adjustments between the two ends of the shaft. There are three worms between the hand knobs and the RA axis so this would be too slow for any visual use. There is a separate manual adjustment with a clutch that goes directly to the final worm. The entire housing on the left rotates with the shaft so it can't be motorized to adjust for sidereal/lunar etc. It may have unfulfilled intent, it is way cool, it will be restored. It might get lightened from some redundancy but I love the chain thing - it's about the size of a regular rubber band. 

Some has already been restored. It should be pretty by week end when I can get back to the pier. 

What a wonderful project.  At every turn you find something beautifully engineered and manufactured.   That is one beautiful scope.



#103 apfever

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Posted 28 April 2021 - 07:30 AM

... so that I could pick up the scope myself! seeing you do this tear down reassures me that the scope went to the right person!

 

 

What a wonderful project.  At every turn you find something beautifully engineered and manufactured.   That is one beautiful scope.

 

Uhhhh, welll, it sure has had it's challenges. This occupied several days with off and on attention. Now I'm back to rock n roll when weather permits for media blasting. My media room is outdoors open roof. 

 

The main pipe was a slip fit frozen with rust, 6-3/8" diameter and 7-3/4" embedment. I ran out of room in the press but the last few inches were loose enough to pound out on the forks. I had to find a pounder for direct reach down into the flange. Too much energy would be lost in pounding stacked spacers where a press is efficient. The concrete anchor bolt (slight industrial size) worked great. The slurry on the pipe is rusty rust dissolver goo. 

 

Now I can move all the scope parts by hand. The green base is 84 pounds. 

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Edited by apfever, 28 April 2021 - 08:59 AM.


#104 apfever

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Posted 28 April 2021 - 08:21 AM

Going back to entry #96,  my first attempt to get the base off failed. I bent the pins on the press at 30 ton. 

After failure, I siliconed the bottom of the pipe inside the base to seal off that end. Then I purchased a soft bolt, cut, drilled, and tapped it to make an injection fitting. I clamped the hose to the fitting, poured in the rust dissolver, and clamped an air nozzle to the other end. This was limited to 120 psi as the hose looked intimidating then. This almost failed since only two of the six holes barely passed any fluid. The other four holes took some in but were sealed internally and the trapped air pushed all the fluid (darker) back into the hose. I didn't have all day to exercise the fluid in and out.  The bolt holes are large and could hold 7cc of fluid. I filled the holes, Teflon taped the bolts, and rammed the bolts in with an air wrench. This worked as witnessed by very high pressure 'needle jets' of fluid rupturing out the top of the base. I did the injections a few times a day for a few days. Chunkage started coming out and I was finally able to use the air fitting on the top bolts. Teflon bolts, then air fitting to keep it flooded while standing up.  Fluid work was done outside. I started with it set up in front of a hot blower vent while I figured it out. 

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#105 apfever

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Posted 28 April 2021 - 08:46 AM

  I have used a 20 ton press to take things apart and it is an impressive  sound when the parts finally let go.  I would imagine that 30 tons makes even a louder bang.

 Lucky for me it didn't BANG.  It oozed the second time but I didn't know it would. Sometimes popping loose can be pretty violent. I kept my distance using a 4' allthread sleeved with a pipe for a handle.  

 

The pier pipe is larger than the A frame of the press. The C channels had to be cut apart and spaced off the frame (red circle). This is why I bent the pins the first time. This time I hammered in spacers to utilize 4 pins. The C channel supports were originally welded together with angle iron spreaders, which I had to cut in half for more spread.  This required everything to be clamped up to withstand a bad release. Not recommended, don't do this at home, just don't. I have a lot of experience with stuff like this, was part of my job, I'm single, and a bit nuts. 

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#106 starman876

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Posted 28 April 2021 - 08:54 AM

This has become a labor of love I see.    It is such  a unique scope that makes it all worthwhile.   Glad to see you have all the equipment to tackle a job like this.   Some of us watching these report are envious of your equipment.  I feel like a second rate tinkerer compared to you.


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#107 ccwemyss

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Posted 28 April 2021 - 10:50 AM

I'm single, and a bit nuts. 

You have a sweet dog. Think of how she'd miss you!

 

Chip W. 


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#108 apfever

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Posted 05 May 2021 - 08:56 PM

Chip, I prefer my projects to thrill me not kill me. 

 

This is going to move fast now and I need input on color control not CA.  Two trips through paint remover and then I built a blast room. Next is using up some small bottles of Naval Jelly,  pressure rinse, and a final dowse in metal prep wash. Then a couple of coats of high zinc content primer. The question is what color layout for the mount. So far, I'm staying with duplicate green for the base and top, and red for the weight and shaft as original. I like red for prominent parts to watch for at night but I don't want this to end up a Holiday Pistachio piece or something to put presents around. A lot of stuff bolts to this pier including two main shelves for the drive assembly. The original white in pictures is not old time original but a more recent rough slap on. The white can go.  This is also getting a full float Alt/Az option by rigging the main pier pipe to a bearing assembly for azimuth. A very simple and super duty bearing I'm building myself. I've done these before. It's what the generator armatures at Hoover spin on. 

 

The main shaft before rinsing the first stripper. 

The shaft after some blasting touch up. 

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#109 apfever

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Posted 05 May 2021 - 09:00 PM

The base after first round of stripper. This has original machining marks inside and on the top edge. The marks are light and I want to keep them. Some testing showed that sand blasting would frost out the machine marks. 

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#110 apfever

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Posted 05 May 2021 - 09:10 PM

Custom rigged blast nozzle to pass the walnut media. This will finish with Naval Jelly and Phosphorus wash. This base casting stripped of everything including paint weighs in at 84 pounds. The weight gave me the idea to do the azimuth bearing. 

 

The paint was very thick hand applied. The paint was also held in by an extremely rough textured casting. It was more like an anchored rubber that gave the blaster a fair run. Stripper twice over was the only way to go first. 

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#111 starman876

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Posted 05 May 2021 - 10:00 PM

this scope was the creation of someone who had a machine shop at his disposal.  Do you think this is a one of or were there more made?



#112 apfever

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Posted 21 May 2021 - 01:30 PM

Probably a custom build but I think it was done by a known scope builder of the time. There seems to be too much insight in too many places for a very talented machine shop person to get it all correct from scratch. There also seems to be some spot welding on the primary cell. That welding was through two 1/4" thick plates. 

 

Any leads on some 3/8 X 40 tpi National STupid Fine?  No time for metric discussions. They are 3/8" diameter by 40 threads per inch. Sometimes this stuff shows up on old UK autos but I didn't have any luck. They look like a factory made set screws, straight slot, with smooth turned spherical tips.  They are the collimation set screws. Great for collimation but sad for replacing with longer threaded clamp knobs. 

 

Did this azimuth thing over a week ago, needed to draw a picture. Schematic and function. There are two main reasons this was a no brainer for this scope. The first was that it is designed for balance in RA over the pier pipe instead of just the DEC shaft and weight like most scopes. The second reason is the bearing assembly was too easy. The scope has complete Alt/Az capability, easy switch, small working space, robust mechanics with close tolerances, ability to challenge a Vixen Polaris for smiles. 

 

The base and bottom race sit on a flat floor. No need for anchoring. Bottom race is common 1/4" thick plate any shape between about 6" and 13" diameter. Bearings are 3/4" diameter and not to scale, nothing is scale but the bearings are way off in particular. Top race is another 1/4" thick plate with closer size requirements. Pier pipe goes on top. All parts stay independent, nothing attaches to nothing. Some of this was getting a little heavy so a friend helped get the pipe in. The above sizes hold the pipe at it's original height.  A good flick of the wrist and this would do 360's. Fun to watch. 

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Edited by apfever, 21 May 2021 - 02:06 PM.

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#113 apfever

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Posted 21 May 2021 - 02:04 PM

The top race is the plate I made to press the pipe out. I didn't damage it. It already had a hole in the middle making careful placement easy by hooking it with an allen wrench.

 

I centered the bottom race by eye. The bearings were hand placed with a dab of grease to hold them in place. Each bearing on a slightly different radius so it would make it's own track. 

The center of the bearings are a comfy 1/4" up inside the hole. This lets the hole retain the bearings. No race is needed numerically. No race is needed in practicality. I'd probably make a race anyway for a permanent installation. This will get one more 5 pack of bearings for a total of 10. 

 

I did not have a decent 1/4" bottom race (that I could see), so I used two pieces of warped distorted 1/16" garbage scraps for the test run. Those are the actuals in the picture, rotated to show each one. Not a problem. This form of assembly tends to have very stable relative bearing positions even with structural anomalies. We flinged this around quite a bit, it was fun to watch. The tracks of the bearings can be seen on both races. There is hardly any shifting including across voids. 

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Edited by apfever, 21 May 2021 - 02:18 PM.

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#114 apfever

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Posted 06 June 2021 - 02:09 PM

Some paint thick patina hand rubbed in. A few days looking into how without abrasive. There is a lot of this patina on a lot more. I cut with 800 grit on some solid block parts till I found this fix here in gallons. 

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#115 apfever

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Posted 06 June 2021 - 02:38 PM

The tube is made of 3 rings.

1. main tube

2. slightly larger diameter ring

3. threaded male end ring

 

The cell and end ring might have been cut from a recognizable pattern? All three parts are end soldered. 

No spacers anywhere including between the glass. Brass to glass to glass and brass contact no oil residue. No glass dust or chips in the cell, very clean. I'm checking if it was opened and cleaned out recently before me. I'm making custom clam hiding foil spacers from 0.0035" foil tack. Clean glass in top of previous photo, clam shown, trying to show the glass as bad as revealing. 

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#116 apfever

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Posted 06 June 2021 - 03:05 PM

secondary maybe came with the primary?  It is on a fixed 45 block attached to a shaft. In Newtonian terms it rotates and moves up and down then set screws into position. I don't know if the prism is silvered, it is blackened and in nice shape. Some marks on the 45 but trivial for this. The block has a single sheet of 'fuzzed' phenolic paper or cloth. This was frozen in had to be punched out - cool thrills ville.

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#117 apfever

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Posted 06 June 2021 - 03:19 PM

Before the after.  Commercial or homemade, maybe recognizable. 

The single line front clip is soldered. Possible this has never been removed, imagining what it's been through, in great shape. 

Collimation was very good, plenty large, it's not in the light path. Finder showed a functioning image before dismantle. 

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#118 kansas skies

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Posted 06 June 2021 - 09:57 PM

Somehow, I missed all this and just took the opportunity to read through the entire thread (I spent the whole hour enjoying this thread while walking on my treadmill). Very fascinating, to say the least. When I saw the original pictures, the thought ran through my head of how I would probably be single by now if I were to have brought this scope home - not that I could have, as this looks to be a project on an industrial level. After reading through this thread, it's obvious that the telescopes landed in the proper hands.

 

Bill


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#119 apfever

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Posted 13 June 2021 - 06:37 AM

Done for use but is any part ever done for eternity?  I put on a little higher shine but am letting some patina soak back in. It will get a clear coat on final installation. Field of view is 2.4o  with nicely matched eyepiece, and 5with optional eyepiece that will stay with the set. 

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#120 apfever

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Posted 13 June 2021 - 07:01 AM

Both ends.  Surprisingly nice views. Microscope eyepieces. I will blacken the front more before final mounting. Field of view just touched Vega, double double, and nearest star from the parallelogram. 

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#121 apfever

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Posted 13 June 2021 - 07:07 AM

Original achromat was glass to glass. I added three 0.003" spacers. The clam is on the inner face of the crown and has a custom blocking spacer that doesn't show in the picture. The other spacers are at 120from the clam. 

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#122 apfever

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Posted 13 June 2021 - 07:20 AM

Laser was to check for Newton's Rings with and without spacers. Nice rings, round, centered with spacers. Laser fun highlighted the edges. I blackened the edges (oil paint, not regular marker) which covered everything in the light path except the clam covered by the custom spacer. 

The crown rested in a friendly machined area of the cell but the flint rested in a larger diameter fully threaded section. I was able to fit a band of plastic around the flint and maintain expansion room. 

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Edited by apfever, 13 June 2021 - 07:22 AM.

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#123 apfever

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Posted 13 June 2021 - 07:37 AM

Eyepiece on right came with it, I found the middle one here identical except for barrel finish marked 50mm.  Eyepiece on the left is a lucky find in my parts marked 25mm.  The Left eyepiece is old, etched reticle cross hairs, and fine helical focus built in. It would be nice to identify this microscope eyepiece. Suggestions? The field lens unscrews as a contained cell, exposing the etched reticle. This piece has a larger AFOV than the other two. It is a nice matching style for the finder.

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#124 starman876

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Posted 13 June 2021 - 08:30 AM

absolutely beautiful.  You are the master of restorations.



#125 apfever

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Posted 13 June 2021 - 09:39 AM

Not hardly, I've refrained from repeating choice words here.

 

 Assembled on dolly with the pier bearings, very convenient azm rotation for assembly.  The paint like patina is surpassed by iron corrosion. I could instantly destroy a gallon of EvapoRust. I did. Several learning rounds of paint stripper, rust dissolver, metal prep acid, sandpaper (found 3000 grit at HD few days ago, used to stop at 800), Brasso, Tarnite, and the barrage from under the kitchen sink. Can't get into all the tools but bigger bench grinder with fat wire wheel get H mention. 

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Edited by apfever, 13 June 2021 - 10:28 AM.



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