4 replies to this topic

[k5apl]

Some months ago, I bid on and won a GOTO Hy-Score 451 telescope with accessories but no mount.  When it arrived, It was apparent why many close-up pictures were not taken.  It had been damaged and repaired-  the tube was in good condition but the focuser and the objective cell had been glued to make them whole again.  And, there was a clam chip on the edge of the objective.

With the help of a nice guy here on  CN I was able to purchase a complete focuser and objective in the cell, and now they are on the tube and the telescope works great.  Its performance actually surprised me with how well it works. Now I understand why GOTO is mentioned in the same company as Nikon and Zeiss.

 

Time rolls on, and I purchased from another auction a Sears Discoverer 60 X 900mm telescope with accessories, no mount, but tripod legs.  The scope needed collimating, and cleaning.  The was an optical flaw in the objective- most bright objects had a red

color on one side and a blue color on the other side.  I tried reorienting the spacer ring, substituting foil spacers, and substituting

brass shim stock spacers.  Nothing worked to cure the colors.  So why not substitute the GOTO chipped objective for the Sears

(TOWA?) objective.  Good idea but the GOTO was just a bit too wide to fit in the cell.  So, the next step was to adapt the GOTO

partial cell to the Discoverer's tube.

 

I found a can of green chili peppers in my pantry that was about the right size to fit over the Discoverer's tube.  I cut it, cleaned it, and epoxied it to the GOTO cell.  I also glued two brass pieces around the O.D. of the cell to help strengthen it from its previous damage.  I used Higgins black india ink to blacken the clam chip.  Painters tape shimming the can on the tube, and electrical tape securing it to the tube aligned the objective to the focuser just right.  The Discoverer came with a finder stalk, but no finder, so I used an old Celestron finder I had on hand.  The telescope has a GOTO objective, Celestron finder, and Sears focuser.  

 

Another auction provided me with an EQ-2 Mount, but no tripod.  The legs from the Discoverer purchase fit it fine.  The tripod tray and the small lamp worked too.  My Frankenstein body parts have yielded a <60mm (clam chip) refractor with really nice images.

I still need to fill in the missing chunk in the objective cell and paint it black, and add a RA motor (Orion) on the EQ-2.  It is a fun

project and has ended up with a usable telescope.

 

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[LukaszLu]

Some time ago I damaged my Unitron 114 lens in a similar way. After unsuccessful attempts to buy a replacement lens, I finally bought a whole new refractor. The truth is, however, that my desperation stemmed rather from the claims I had towards myself for carelessly playing with the disassembled lens. The image after this damage did not change noticeably and I guess it was just to not see the chip and not recall the unpleasant moment when I heard THAT SOUND, before I understood and saw what I had done :-)

 

And the new Unitron - I guess it does not give a better image at all, even though the lens looks like new... Great that you made use of this lens if you happened to come across good quality optics!

[k5apl]

Yes, it is heartbreaking when we have an accident with our astronomy stuff.  I have dropped eyepieces and a friend

dropped my binoviewers.

 

I have the same findings as you did-  I cannot visually see any difference between the complete telescope and the

clam chip telescope.  I did compare objectives before starting the project, and it gave me incentive to carry on with finding a way to use the clam chip objective.  Many thanks to CN Classic Forum members for ideas and tips.

You can see from the photo why I call it my <60 telescope---but I haven't calculated the amount of area lost.

The other photo is the GOTO objective, Celestron finder, Sears tube and focuser, unknown mount origin, and Sears

Discoverer tripod legs.

 

Clear skies for you

Wes

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[deSitter]

Yes, it is heartbreaking when we have an accident with our astronomy stuff.  I have dropped eyepieces and a friend

dropped my binoviewers.

 

I have the same findings as you did-  I cannot visually see any difference between the complete telescope and the

clam chip telescope.  I did compare objectives before starting the project, and it gave me incentive to carry on with finding a way to use the clam chip objective.  Many thanks to CN Classic Forum members for ideas and tips.

You can see from the photo why I call it my <60 telescope---but I haven't calculated the amount of area lost.

The other photo is the GOTO objective, Celestron finder, Sears tube and focuser, unknown mount origin, and Sears

Discoverer tripod legs.

 

Clear skies for you

Wes

 

You only need cover the clam by a circular (perfectly circular) lune of black paper in front of the lens (for solar use). The only real harm it can do is a tiny reduction in brightness, undetectable, and a very slight increase in diffracted light so a very tiny loss of contrast, also undetectable. There is no loss in resolution - not even undetectable, none whatsoever.. Uncovered, it can however scatter a lot of extra, unfocused light into the image when viewing the Moon.

 

As for breaking/dropping things - it's awful just to read the stories. I have never dropped anything because I think of all the ways I could screw up beforehand. Visualize what might happen. This seems to work

 

-drl

[LukaszLu]

The other photo is the GOTO objective, Celestron finder, Sears tube and focuser, unknown mount origin, and Sears

Discoverer tripod legs

The tube, the tripod as well as the mount look like typical Towa products and could easily come from the same telescope. But the most important thing is that you have a lamp. The lens is a secondary issue - the most important thing is the lamp :-)

 

 

I have never dropped anything because I think of all the ways I could screw up beforehand. Visualize what might happen. This seems to work

Well... sometimes it doesn't work. Especially when you're tired and it's late. I've dropped a lens a few times and it was always at the very end of work. Then you lose concentration, your alertness drops - and the worst thing is to get the idea to "try one more, last time"... You only snap out of this blissful carefreeness when you hear THAT SOUND... :-)

Edited by LukaszLu, 06 May 2025 - 04:17 PM.