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Criterion Dynascope 12 saved from doom!

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#26 upwinddan

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Posted 01 May 2020 - 09:31 AM

Great story! Keep us posted.
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#27 DAVIDG

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Posted 01 May 2020 - 10:28 AM

 Congratulations on  a great find !  I look forward to watching the restoration. I highly recommend that you test the primary and secondary or have it tested by someone that can test it correctly. Over the years I have seen a number of larger commercial Newtonians with optics that were not very good. I have received PM about other 12"  Criterion Newts that when tested, the primary turn out to  have serious. issue and " was almost  a sphere ". Your going to spend many hours in a  labor of love to restore it mechanically.  Testing the optics which are the heart of any telescope will show if they need attention as well and will take much less time then the mechanical restoration .  As I  have said many times 1/2 wave or even worse don't give a fuzzy image that won't come to focus so many are under a false impression that all is well but  optics of that  poor quality will never give you high magnification images full of "spacecraft flyby" detail  that true 1/8 wave optics  will. 

 

              - Dave 


Edited by DAVIDG, 01 May 2020 - 07:17 PM.

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#28 Jason H.

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Posted 01 May 2020 - 12:14 PM

Wow! What a fun restoration project! I’ve never seen the 12”. What is the fl?

Thanks, and it looks like it's about f/6.3.

 

And for others, once (and if) I get the focuser working and the collimation working (I'll be pulling the mirror cell out at some point to see what's going on down there, but I haven't touched it yet, it's sort of like an archaeological dig right now (having regretted doing the bull-in-the-china-shop thing before), I don't want to over- torque those oxidized elements yet until I clearly understand the final state it was in before locking up, not saying that it was good before, but I'm interested in seeing what the last person who fiddled with it was doing, i.e. did they know what they were doing or is it totally whacked out, as I'd expect it would be.)  Before I even get the focuser back on line, I'm going to drop a cheshire collimator in the EP holder to see what's going on (how whacked out is it?).  Just curious about that after so much environmental damage and people setting it resting on the mirror-end bolts on hard concrete, dirt etc.  Obviously I don't expect it to be collimated at all, but my RV-6 and 8 can take a ridiculous amount of abuse in transit and still hold collimation, and I just have to know if this beast made it through that kind of evident environmental punishment. I expect to be able to pick up the mount this weekend, so if I can get it up onto that, I'll try to get it to the point where we can see what's going on optically (I have absolutely no idea how the mirrors are other than to say that it's scary looking down the tube at the dust (but I've seen what apparently was worse come out better on the cleaning; very hard to see from this distance (the end of the tube), but I have my fingers crossed that I will eventually be able to have them re-coated, and I should be able to get a rough idea about that sooner than later, once I have it up on the mount.  No matter what I have to pull the mirror cell, just want to understand it's current state before moving on (it's only an odd curiosity to me, that I can't re-create that alignment state once I start fiddling with it.)

 

Jason H.    


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#29 starman876

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Posted 01 May 2020 - 12:52 PM

Congrats on an awesome find. Good luck with the restoration.
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#30 Sean Cunneen

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Posted 01 May 2020 - 01:53 PM

I restored one of those a couple years ago for a Camp in Michigan that had it housed in an observatory for 55 years!
It was a great project but took a LONG time to get apart! Liquid wrench, a torch and lots of patience will be your friend.

I second DavidG's recommendation about testing the mirror, mine was one that he aluded to being very near spherical... The thread is somewhere in CN antiquity. As the mirror still focused, the camp board decided it was fine and my tests were probably off(!) Because the strehl was in the 40's.
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#31 Jason H.

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Posted 01 May 2020 - 04:29 PM

This gives a clearer view down the tube.

 

2smDSC00563.jpg



#32 Jason H.

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Posted 01 May 2020 - 04:36 PM

And this is through the focuser.  That scary looking junk on the right, that looks like damage in photo, but I believe it's actually just old spider web in the path; you can see how the mirror actually looks in the post above this one.

 

smDSC00564.jpg


Edited by Jason H., 01 May 2020 - 04:47 PM.

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#33 Jason H.

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Posted 01 May 2020 - 04:43 PM

I don't know the function of this yet, I'll have to look it up, but perhaps for an armature rod that holds something (a camera or projection plate?) to hover over/near the eyepiece?

 

2smDSC00568.jpg


Edited by Jason H., 01 May 2020 - 04:51 PM.

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#34 CHASLX200

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Posted 01 May 2020 - 06:08 PM

I don't know the function of this yet, I'll have to look it up, but perhaps for an armature rod that holds something (a camera or projection plate?) to hover over/near the eyepiece?

 

attachicon.gif2smDSC00568.jpg

May have been a cam holder.


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#35 DAVIDG

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Posted 01 May 2020 - 06:47 PM

I don't know the function of this yet, I'll have to look it up, but perhaps for an armature rod that holds something (a camera or projection plate?) to hover over/near the eyepiece?

 

attachicon.gif2smDSC00568.jpg

 It is part of the camera mounting system. A rod fits in the brackets and there is another bracket with a slot in it that a bolt goes into that screws into the body of camera to hold in it place above the focuser.

 

               - Dave 


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#36 oldejames53

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Posted 02 May 2020 - 12:28 AM

Edmund sold those as an accessory.  It consisted of the bracket which you pictured, a section of aluminum pipe about 24" long, another bracket which would attach to the aluminum pipe, and a white aluminum screen about 6" square.  The bracket on the pipe could hold a camera over the focuser for either prime focus photography or eye piece projection photography.  The white screen could also be attached in lieu of a camera for projection viewing of the sun.  The holes in your telescope mounted bracket which parallels the tube were simply there for storage of the apparatus when not in use, even though doing so it still managed to get in the way of any and all observation, so I just left the pipe and all off.  I watched the total solar eclipse in Virginia (1972?) on the projection screen of one of these gizmos attached to my Edmund 4.25" Newt.


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#37 mattyfatz

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Posted 02 May 2020 - 12:57 AM

That focuser looks like it has a longer base plate that the 6", 8" versions. It will probably be hard to replace. If you can get those four mounting screws loose to remove it, you'll be in business. After you get it free from the tube, I'd suggest soaking in warm oil for a few days. Fully submersed in the FLA sunshine out to do it. 


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#38 John Higbee

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Posted 02 May 2020 - 03:51 AM

As the owner of the much less expensive Criterion RV-6, and an RV-8, (having gotten some good planet images out of them too) there was a telescope that I was looking for almost daily for years and years (but didn't think I could afford even if I found it) on CN, Craigslist, EBAY and everywhere else (looking maybe for 12 years-ish?)  One guy who is on CN even once promised me years ago that he'd deliver a 10" on a trip down the coast of FL (he broke his promise.)  Maybe about a year ago or two ago I pretty much threw in the towel on ever getting a Dynascope, but checked periodically on those forums just in case :^), but I was pretty much resigned that I would never find one.  Then, out of the blue, last night I got a call from a woman I've known for years (but hadn't heard from in as many too) she asks me would I like to come get a telescope that she has.  I had already said yes, and then she said it was a Criterion, and I was like wow (in my head) and then she said it was a 12 inch, and I was like OK, she probably measured the OD and it's really a ten (but I was still elated and was thinking, my luck couldn't be that good, nobody in the entire Universe knows how much I want one of these, what are the odds of one finding its way to me? Really!!!)

 

She had tried earlier on to bring it to the dumpster at the storage place but it was too heavy.  She left it in the hallway at the storage place and somebody complained that it was blocking the way.  Thank goodness her husband told her to bring it back into the unit, and I am so thankful that she remembered me and called.  I'm told it was originally from a well-known affluent family in South Florida, and had been left outdoors (sideways) for a long time by the subsequent owner.  Then it was brought up here to storage near Daytona Beach.  Today I picked it up where it was left for me, not far from the dumpster. :^)  I'm picking up the mount this weekend (hopefully).  It's the big HEAVY observatory one!  I'm told it will need a lot of work, but so will the rest of the scope as you will see in the following images, but I look forward to the adventure!

 

attachicon.gifIMG_1987.jpg

What a find, Jason!  Congratulations!  This will be a "restoration to remember"!   John


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#39 highfnum

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Posted 02 May 2020 - 04:19 AM

a rare bird 

worth saving 

 

i have rv-6


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#40 RichA

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Posted 02 May 2020 - 05:36 PM

Serial number 1590

 

attachicon.gifsmDSC00549.jpg

Amazing looking paint finish. 


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#41 John Higbee

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Posted 03 May 2020 - 08:20 PM

Dis you get the mount this weekend?



#42 Jason H.

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Posted 04 May 2020 - 06:40 PM

Dis you get the mount this weekend?

Hi John, no.   Although I've had been in constant texting contact with him over the weekend, he still hasn't given me the green light yet to come over to pick it up.  He did provide me with some interesting tips on various types of lubrication, and on freeing up the focuser (which is now working, I won't post images of the before and after until I've completely redone the focuser and have the mount here to do a test of it all together.) The current telescope mount location is very near my home, but the current scope mount owner lives one hour away in Daytona Beach area (the place the scope mount is near me just north of Orlando at his other home) and he is not able to make the scope mount available yet.  He tells me that he read our posts the night I posted them on this forum about this telescope.  I worked on some of the OTA elements over the weekend (I did take some shots that I'll eventually be posting after the mount comes, but would like to get it up on the mount to do some of the adjustments for some other shots; I don't want to do a drawn out spamming of the forum with images of minor screw thread cleaning or polishing, so I think I'll post a bunch all at once when a few more interesting shots can be done, so people don't have to keep checking in only to see a post for brass screws :^)  .     


Edited by Jason H., 04 May 2020 - 07:07 PM.

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#43 Jason H.

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Posted 10 May 2020 - 10:22 AM

So starting with the focuser, we had a seized tube due to oxidation.  Looking inside the tube you can see how the iron oxide crept higher than the edge of the brass tube.

 

smDSC00589.jpg



#44 Jason H.

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Posted 10 May 2020 - 10:24 AM

With a little Silicone Liquid Wrench and a steel wool pad, that cleared out nicely.

 

smDSC00603.jpg



#45 Jason H.

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Posted 10 May 2020 - 10:27 AM

With the tube free, it's time to break it down further.

smDSC00608.jpg


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#46 DAVIDG

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Posted 10 May 2020 - 10:29 AM

 Having restored many telescope and cars, you don't have a "basket case" but a very restorable  telescope. From what I see it has some minor corrosion. Heat and penetrating oil will get things apart then sanding, priming a paint will bring the parts back to new condition. The key is to take your time and don't force anything to get it apart. Like  heat and penetrating oil and a bit of patience  to allow things to work are your friend. It amazing what heating a frozen bolt with a propane torch will do  to break it free.  Good Luck !

 

               - Dave 


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#47 Jason H.

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Posted 10 May 2020 - 10:37 AM

On this side you can see the brass focus lock screw (in great condition inside the threaded portion) and a detente hex screw that keeps it aligned.  Although these focusers have been much maligned over the years, as a user of a similar design on the RV-6 and RV-8, I had to learn that this focuser, so long as it is opposed in tube rotation to the counter-weights, is the most robust focuser you can have regarding weight load.  It will not travel at all even with a barlow, heavy eyepiece, an old Orion Steadypix camera mount (heavy itself) and a point-n-shoot camera on it, IF you have it opposed to the weights.

 

 

smDSC00609.jpg


Edited by Jason H., 10 May 2020 - 08:43 PM.

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#48 Jason H.

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Posted 10 May 2020 - 10:40 AM

Most oxidation is off here.

smDSC00649.jpg



#49 DAVIDG

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Posted 10 May 2020 - 10:56 AM

 I have restored a number of these focuser and like you said when adjusted correctly they work very well. One of  the main issues I have found is the U shaped cap that fits over the pinion gear and applied pressure to the shaft. The slots that the shaft fits in gets worn so the cap will bottom out before it can put pressure on the shaft. The result is  the pinion and shaft  is loose and the  focuser feels sloppy. By just sanding down the back of the cap, it now won't hit the focuser body and you can adjust the pressure on the pinion with the two screws that hold the metal plate that goes across the cap. A little grease in the focuser tube and pinion gear and these focusers  are smooth and work great.

 

   By the way you can still get the black wrinkled paint that  was on many parts and the mount of this scope. It  is made by VHT and many auto parts store sell it or you can get it on line.

 

 

                    - Dave 


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#50 Jason H.

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Posted 10 May 2020 - 10:57 AM

I'm thinking Rustoleum Rust Reformer would be overkill here?  Should I prime it?  What color and paint? [EDIT - I SEE DAVIDG's post above, written while I was drafting this]  (I've read some other posts on this, but I can't find a direct reference to doing the iron elements on the Criterion's yet.)  Speaking of paint, if anyone wants to comment on any and all aspects of paint here, I'd very much be interested in that.  I really don't want to go metal flake or neo-post-modern on this one, so does anyone know if there is there an off-the-shelf matching crinkle green Criterion spray paint out there? I probably would wait and go Icon Derelict on the tube until a good solution came along? (I think they spray clear on the old surface to stop further decline?).

  

smDSC00636.jpg


Edited by Jason H., 10 May 2020 - 11:04 AM.



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