46 replies to this topic

[Kasmos]

Now on to the objective.

It's main 2 parts are the front cell and onepiece dewshield and the rear connecting ring.

 

Like the focuser, I wasn't completely sure how it should be removed.

Like the focuser it's threaded onto the main tube, but this time there are three small grub screws that need to be loosened before doing so.

I had to use some WD-40 and go back in forth and loosening and tightening it a little at a time to unscrew it without force.

I forgot to mention in the last post, that this was also true of the focuser.

 

Two of the grub screws can be seen here. I marked just above the third one with a white cross to index it's location.

The white dot below it is on the main cell body to mark how they go together.

 

The cross mark on the inside corresponds to this piece of tape on the tube and the dimple left by the grub screw.

When reattaching the cell I'll shine a light in the grub screws hole to see when the dipple is centerd.

 

The arrow points to a piece of tape that aligned with the one on the tube.

I'm glad that I marked how it all originally went together. You'll see why.

 

With the rear tube connecting ring off, it shows a few things.

The arrow points out a paper spacer that collimates the cell with the rear connecting ring.

The cross mark alings with the one made on the connecting ring.

At about 11 o'clock there's glue to hold the retaining ring. Slicing it along it's seam made it easy to unscrew.

The matt like finish idicates that it's rear surface was machined.

 

The spacer appears to be black construction paper. I scratched it's outine on the cell so I'll know where it goes.

This link (scroll down a bit ) shows another 451 with the same type of spacer so it's probably common.

https://www.cloudyni...unt/?p=10302019

 

Here's a view of what I've been calling the rear connecting ring.

 

Once out of the cell I found that the objective's alignment marks have moved. The crown is on the bottom.

It wasn't a complete surprise since the lens rattled quite a bit from being loose in the cell.

I had previously made marks on the cell's edge to show where the three spacers landed but they were now voided by the rotation.

That said, I ended up installing the crown where it was, thinking most likely, it was the flint that moved.

Just a shot of the misc. hardware.

 

The retaining ring seems thicker and heavier than most found on 60mm scopes that screw in from the back.

 

To be continued...

Edited by Kasmos, 16 May 2021 - 08:16 PM.

[Russell Smith]

Nice to see you working on this goto again.

I need the info.

 

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[Kasmos]

Nice to see you working on this goto again.

I need the info.

I've seen others with a visual back like yours, but I don't recall seeing a black pinion cover. Can we assume it's plastic?

 

I also see, like mine, yours has a build of grime where the focuser rotates. Mine is missing or never had the Japan badge at ther bottom. 

 

Lastly, what's going on with your finder? it looks like another one is shoved into it.

Edited by Kasmos, 17 May 2021 - 04:33 AM.

[Russell Smith]

I have to assume the finder has been dropped multiple times over the years. It has been repaired with PVC and I think part of a vacuum cleaner. It just fell apart soon after this photo was taken and is in pieces. 

The cover seems to be some early plastic. Bakelite?

 

 

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[Kasmos]

Finishing up with the Objective.

 

All of the components were washed then polished using Blue Magic.

 

A few things regarding it's reassembly.

I tried rotating the elements to see if it effected the Newton Rings and it didn't, so I aligned them with their original marks.

I also tried taping them together so they wouldn't rotate when the retaining ring was tightened.

For some reason once assembled that screwed up the Newton Rings so I removed it.

By what was left of the glue and how much it had rattled I could tell the point where the retaining ring had previously been.

I then found I had to have it much tighter to keep the Newton Rings centered.

The good news. Neither lens rotated once it was tightened up and there's still a slight rattle.

 

This just shows the gap created by the Collimation Shim.

The gap looks fairly big to me so I hope it's correct.

I wonder if the scratches near it are from the assembler fussing with it?

 

Once again I used tape on the outside to help me posistion it where it was.

 

Before reinstalling the focuser and objective the tube was cleaned and then treated with polishing compound.

The tube was very dirty and appeared to be stained by Tobacco.

I believe it took more time than any of my other scopes to remove all of the blotchy yellow stains.

Edited by Kasmos, 17 May 2021 - 03:51 PM.

[semlin]

cool.  i did not know you could use metal polish for a painted surface like that.

[Kasmos]

cool.  i did not know you could use metal polish for a painted surface like that.

Blue Magic was used on the plastic parts (lens cell parts and cap), and polishing compound (Turttle Wax brand), on the tube's paint. In the past I've experimented with Blue Magic on paint and did try it in some places on this tube's paint, but it didn't do any better, so I went over all of it with polishing compound. The good thing about the polishing compound, it doesn't leave any waxes behind so you can touch up the paint without worring about removing waxes. That said, before doing any paint touch ups I usually clean the surface with something like mineral spirits and or a cleaner like Simple Green or Awesome to remove any powdery residue left from the compound.

 

Bottom line, I've personally found Blue Magic safe to use as a mild polish on paint, but it's made to leave a anti-oxident film for metals. Like anything, you'll want to test it and at least at first, don't rub too hard. Lastly, I'd never recommend using Rubbing Compound as it's way too gritty and will scratch and remove too much paint.

Edited by Kasmos, 17 May 2021 - 10:33 PM.

[Kasmos]

Finder Restoration

 

Like several other accessories, the finder came in pieces. Thankfully it was all there.

It's tube, like with most used scopes, suffers from many scrapes and scratches.

 

Back when I first received the scope, one of the first things I did was fix the dent and reassembling it.

For some reason the threads don't start until a bit into the tube, this makes the eyepiece barley attach. 

Note the black paint near the crosshair cell. The paint made the cell unable to budge.

So I used a brush with laquer thinner to soften it and wipe it out.

 

Since it's a bit deep down inside I cut two nails and used circlip pliers to get it out

I should have taken a photo of the other side of the cell to show how it's beveled to a knife edge towards the apeture. 

 

I tried removing the old solder with a soldering iron but had no luck.

So ended up using a razorbIade to scrape them off.

I used two pieces of my own hair and attached them one at a time.

I tape them down and to increase tension, progressively add more tape moving towards the cell

Then put a dab of super glue on each end using a toothpick.

 

The hardest part was getting the cell started back onto the threads.

It kept getting cocked and or jammed so it took several tries before success.

I decided not to repaint the threads black near it. At least until I know they are at best focus.

Also, before I took it out, I made a little depth gauge so I'd know closely where it was.

 

The objective's retaining ring was tight in the cell/dewshield

so I made a remover from a broken X-acto blade and small Vice Grip.

 

Cleaned and ready to go back in service.

Goto says it's a 17mm but I believe it measured larger (19mm?)

I suppose 17mm is the clear apeture.

 

The eyepiece had to be taken apart for proper cleaning.

It had lots of sticky grease to make it focus smoothly.

Now it's greaseless so it feels a bit loose but i can live with it.

That said, I have some thick grease that I may try.

 

They might be a little thick but no thicker than on some other finders I have.

 

It's always a pain and takes patience to clean these little adjusters.

 

But when finished it's worth the effort.

 

more....

Edited by Kasmos, 18 May 2021 - 02:58 PM.

[Kasmos]

Finder Continued

 

I made a little stand to make the touch ups easier.

Like the OTA the tube was first rubbed out with polishing compound.

 

The mount was washed and a few chips were also touched up using flat black.

Although wrinkle paint isn't flat, flat black hides the chips better than semi or gloss.

 

 The metal ring and dewshield/cell were polished with Blue Magic.

 

While the touch ups are more noticable in person, from a couple of feet, they completely dissappear.

 

 

Since I was in the mode I also touched up the OTA. 

The box made it easy to rotate and do the touch ups.

The good news, most of it's chips were on its bottom.

 

The key to doing good touch ups is to work it by puddling the paint just up to the edges of the chip.

Then, keep it somewhat level and let it tack up before doing another so it doesn't sag to one side.

Also, unless the chip is really small or the paint is already thick, it may take two coats.

Especially since it shrinks and flattens out after it dries.

 

 

[Terra Nova]

Both of my Goto refractor’s finders had the cool little objective cap attached to a teather.

[PawPaw]

Kasmos,

 

Can I  send you my Goto hyscore 451?  Amazing work!

 

Don

[Kasmos]

In May I started on the mount but then left town for awhile, so now I'm back back at it.

 

Everything that would come off was cleaned degreased and or polished.

 

The scope as purchased was missing the hub, but thanks to Stew, I purchased another mount for it's hub.

A former owner had already done some touch ups, but they were done over some crusty corrosion.

 

The way these mounts were made, each component (saddle, body, and hub), are a slightly different gray. 

The hub being a little lighter and a bit greenish in color.

 

First I polished the hub using Polishing Compound but it seemed to make it look even greener so I stopped.

I then spot sanded the old touch ups and the underlying corrosion, before repainting them.

I re-discovered a 20-30 year old can of Machinery Gray I have that was still good.

(Zynolite Epoxy Rust-Mate from Standard Brands Paint Co. I loved these paints)

It's about a perfect match you could ask for the main body, but a little off for the hub.

(it was also perfect for some recent touch ups on the Mayflower 814)

 

This was really just an experiment until I could find time to completely repaint the hub.

Since the hub is a slightly different color than the main body the touch ups show a bit,

but are acceptable. 

 

Just another view showing some touch ups.

 

The tangent arm was completely repainted using a brush.

This old paint really levels well so it doesn't leave much in the way of brush marks.

If you go back to Post #16 you can kind of see how bad the tangent arm was.

https://www.cloudyni...-451/?p=9454060

 

The main body and saddle only needed a few very small touch ups.

 

The flat of the facing hub tine was very chipped and corroded, so it was completely repainted.

Because the lighting naturally changes at the edges, any slight color change isn't very noticable.

 

Again, I really thought I was going to have to completely strip and repaint the hub.

If I knew how good it would come out I would have spent a little more time addressing some of the corrosion on it.

As for now, I like that it's retains the original paint and if any spots bother me, I'll readdress them.

 

I don't know when I'll get the time to build some legs, so for now I'll probably use some extras from a Unitron.

Especially since I'd like to see how this scope performs.

 

A question for other 451 owners.

The OTA attached to the mount with hub (as shown above) will fold and stow in the box.

It's a somewhat tight fit with the hub attached,

so did these scopes originally come stored that way?

Like a Unitron you would think they would be separated at the saddle for storage,

plus having the tube off the mount would make installing the legs easier.

Edited by Kasmos, 30 June 2021 - 03:50 PM.

[Van Do9:3]

Fantastic restoration Chris! The 451 is my favorite classic that I have. The compression fit of the focuser tube holds so nicely that I use a .965” to 1.25” adapter for modern accessories. But the native .965” diagonal and EPs are a pleasure to use.  
 

My

[Stew44]

I believe the hub was not stored in the case.  If you can get it to fit then that's a good thing.  Earlier cases including the Uranus IV (1953-54) have a hole for the mount shaft sans hub to slide into while still attached to the scope.

[Kasmos]

I believe the hub was not stored in the case.  If you can get it to fit then that's a good thing.  Earlier cases including the Uranus IV (1953-54) have a hole for the mount shaft sans hub to slide into while still attached to the scope.

Thanks Stew.

Like mine, I've seen some other 451s with the mount attached to the OTA and without the hub and this lead to some of them being lost with the legs. For ease of use and storage, I'd like to build a separate box for the tripod like the older Unitron 114s did.

 

By the looks of this NOS model 201 on Zen, it's packaging suggests that the mount might be intended to be kept separate, although that just may be for its intitial shipping. 

https://zenmarket.jp...Code=o484330533

 

Also, the layout of it's boxes compartments is a bit different from all the others I've seen.

Edited by Kasmos, 30 June 2021 - 10:38 PM.

[Terra Nova]

Thanks Stew.

Like mine, I've seen some other 451s with the mount attached to the OTA and without the hub and this lead to some of them being lost with the legs. For ease of use and storage, I'd like to build a separate box for the tripod like the older Unitron 114s did.

 

By the looks of this NOS model 201 on Zen, it's packaging suggests that the mount might be intended to be kept separate, although that just may be for its intitial shipping. 

https://zenmarket.jp...Code=o484330533

 

Also, the layout of it's boxes compartments is a bit different from all the others I've seen.

Goto 201.jpg

I always kept the mount of my 451 in another box.

[ColoKeb]

A friend brought a GOTO 451 over for me to check.  It is pretty complete.  He would sell it but the view looks like you are seeing thru smeared applesauce.

 

I suspect this in the lens as it is the same with the rt angle finder or image reverser.

 

Can this be fixed. or could a modern 60mm f15 (900) be swappeLocation:  Colorado

[Kasmos]

A friend brought a GOTO 451 over for me to check.  It is pretty complete.  He would sell it but the view looks like you are seeing thru smeared applesauce.

 

I suspect this in the lens as it is the same with the rt angle finder or image reverser.

 

Can this be fixed. or could a modern 60mm f15 (900) be swappeLocation:  Colorado

Many issues can be fixed, but there's no way to know what's wrong without seeing or knowing more. A modern lens could be swapped but it may not be as good and it would very much devalue the scope. It kind of sounds like you don't have experience working with lenses and telescopes, so it might be best to get a different one.

 

If you can upload some photos of the objective it might help, and if you go that route, it might be best to give it it's own dedicated thread/topic.

[PawPaw]

Agree with Chris.....pictures are a tremendous help.  Goto's have a reputation for good quality control on their objectives and all accessories.  Their mounts were among the best made.  Without seeing pictures we can only guess.  Don't dismiss it without further testing.  

 

Don

[Russell Smith]

The go-to 451 OTA I have fits ( snug ) in a Unitron 128 cradle, if that helps.

[Kasmos]

The go-to 451 OTA I have fits ( snug ) in a Unitron 128 cradle, if that helps.

You don't say 

 

 

Actually, I just need to buy some bolts to attach it's mount to some Unitron legs.

 

p.s. thanks for bumping this thread.

[Bob4BVM]

Thanks for posting your work here

I just bought a Goto 451 (thank you Jimeh ! ) and am looking forward to restoring it.

A brief look at Luna last night has me enthused with this sweet little scope !

 

On mine the ALT slow-mo works, but the AZ knob has no effect.  Will have to see what i can figure out on that, maybe i am just not operating it right.  Anyone have a manual on this scope / mount ?

CS

Bob

Edited by Bob4BVM, 10 April 2025 - 12:53 PM.