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ED80S fell on the floor

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#26 eyespy

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Posted 28 July 2020 - 11:49 PM

Hi DUbeni,

 

If you have a hobby shop nearby, see if it carries an acrylic paint by Tamiya.  Colour code is 'Flat Black XF-1'.  I am sure that there are other makes.  Acrylic model paint is easy to clean up with 99% Isoproyl alcohol even after it has fully dried.  It's the same alchohol used for cleaning lenses so is OK to use.  I would use a small camel hair artist paint brush and try to paint the actual chipped area if possible, depending upon which side of the lens is chipped and maybe 1/2mm beyond onto the undamaged glass.  One coat should be enough.  If it doesn't work, you can just remove the paint with the alcohol and lens tissue.  I have used this method for blackening the edges of lenses etc and even to paint out a 5mm band around the edge of a reflector mirror to 'cover up' a turned edge.  You will be able to see the painted area in the out of focus positions but not when in focus.  The main thing is to remove any glints, scattering and defects in the image by preventing the light from passing through the chipped area.

 

I found that most marking pens are too transparent and do not cover the shiny edges very well.

 

Good luck.

 

Doug.......


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#27 dUbeni

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Posted 29 July 2020 - 04:41 AM

Thank you very much Doug, your reply is very helpful. waytogo.gif

The glints and scattering were more obvious when observing Jupiter. I know seeing wasn't helping, but the scattering was at an annoying level, really interfering on the observing.

The chipped lens is the outer one, in the photos of the lens cell one can see the whole shim from the inside, from the outside the shim is slightly obstructed by the chipped outer lens.

That is why I masked it with a bit of tape, just for testing on the next good seeing night. If it helps with the scatter, I will follow your instructions. laugh.gif

 

Bernardo



#28 dUbeni

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Posted 29 July 2020 - 07:34 AM

Fourteen months ago some kids were racing on the street outside where I work and one decided to cut off the other, causing him to lose control of the vehicle and collide with a string of three cars.  In total, five cars were destroyed in this accident.  Three of us were inside at work.  

 

My car was one of those destroyed.  It was a 2014 Honda Accord in very good shape, with only 57k miles, and probably good for 150k more.  

 

The insurance company gave me $12000 and buying another one cost $22,000.

 

What I'm getting at here is that sometimes you just have to look at the smoking ruins and open your wallet and pay.  It sounds as if you have done all that may be done by way of appealing to those with expertise.  So now go out and buy a refractor.

 

Yah yah, go out and get the Vixen ED81s, or SD81, whatever they are calling it now.  f/7.7, 81mm.  Excellent color rendition and a sharp image.  You will be happy.

 

Greg N

Hi! Greg, I know that feeling, more than a decade ago I wrecked my Nissan Micra driving at night on a dirt road, I ran over a small boulder and the car tipped and rolled, I was unharmed. Unfortunately the insurance company only payed less then half it's value.

Unfortunately I just spent a ton of money on a paint job of our current family car, a VW Passat van. So all my plans have to be postponed.

Now! I really like all the suggestions presented here, but in order to keep up with my plans of getting a decent 5" ED or APO refractor, I'll have to stick with a used one, a really good one preferably cool.gif . I'm not in a rush because I can't afford anything now.

 

Note: I like the poor man's Taks, Japanese Vixen's are great.

 

Bernardo


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#29 dUbeni

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Posted 30 July 2020 - 08:08 AM

Hi! to you all,

I'm just reporting on last observing experience to tell you that I'm coming to a truce with myself and the telescope. flowerred.gif

After a week of terrible seeing, last night was nice to have a slightly better seeing, maybe Pickering 3-4, poor anyway.

I first did a brief star test on Arcturus, and it shown occasionally nice concentric rings inside and outside of focus, with the obvious flattening on the side where the tape is. This time there was less color (purple) on the inside focus. In focus I could see the Airy disk dancing a bit with shattered rings.

Then I observed the Moon with UO 16 and 20mm Erfles and it was nice and sharp with no color on the limb. The 5 and 9mm orthos presented nice contrast and features on both Clavius and Copernicus, even with the distracting wavering.

Later when Jupiter came into view at my location I used the Vixen HR 3.4mm to push the view beyond it's limits, 0.38mm exit pupil, magnification 212x. The image was a bit soft, mostly due to seeing, on those fleeting moments where it became sharper the GRS was presented as a nice oval brownish red. On good nights this combination have given me sharp details on bands and ovals, with no breaking of the image.

Saturn was a bit easier, but I wasn't able to see the Cassini division, just some banding on the surface of the planet and two moons: Titan and Rhea.

While waiting for the giants I also observed some open clusters northwest of Sagittarius.
The session ended around 4AM with another brief star test on Altair.

 

My next question is: is it safe to transport to a dark location? I'm concerned with the car vibrations, even if well packed.

 

Thank you all, your input has been very helpful. bow.gif thanx.gif

 

Regards

Bernardo

 

Edit: the FOV of the Vixen HR 3.4mm is 0.2ยบ - 12'


Edited by dUbeni, 30 July 2020 - 08:12 AM.

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#30 Nippon

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Posted 30 July 2020 - 11:31 AM

I use a Vixen clamp from a Porta bolted to a Losmandy D plate to use my Vixen ED103s on my GM8. My 103 has the standard stock Vixen dovetail that came with the scope. This type of dovetail can't slide out it can only tip out when the two bolts are loosened sufficiently. I'm at a loss as to how it came loose. I feel for your situation I'd be sick about it and probably tap my savings and order a new SD81s and if that was not possible I'd put it in a box and try to ignore that it happened until I could replace it.


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#31 Nippon

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Posted 30 July 2020 - 11:40 AM

If I remember the ED80s is the scope you were going to take on vacation. If it's just a chip with no tiny crack extending from it my thought is it would be stable and no more delicate to car vibrations or normal usage bumps then it was before.  



#32 dUbeni

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Posted 30 July 2020 - 08:23 PM

If I remember the ED80s is the scope you were going to take on vacation. If it's just a chip with no tiny crack extending from it my thought is it would be stable and no more delicate to car vibrations or normal usage bumps then it was before.  

Yes, it is that same scope. I don't see any extended cracks but I'm still concerned. I may be taking the R200SS instead, it will be a nice first run of the SXD2 mount at a darker sky location. We still haven't decided where and when to go.

 

The clamp I have on my older side by side plate is one of those with springs and a small bar that holds the telescope in place (photo on post #1). The dovetail bar is like yours. It happened because I was on the wrong side of the telescope fixing the dew heater strap. Those springs are tricky and tightening in the dark can be deceiving, because although the knob feels tight I had just compressed the springs and not the bar on the previous night. I must have lifted the front of the telescope while fixing the strap and it slid right off. Believe it or not the Baader T2 Zeiss prism didn't suffer a thing, and it was the first to hit the floor.

 

I really like the Vixen dovetail bars and clamps for my small telescopes, they make me feel safe.

 

Bernardo



#33 Nippon

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Posted 30 July 2020 - 09:07 PM

Okay that saddle looks like an older one from a Stellarvue Alt/Az. Makes more sense now I too feel secure with the stock dovetail in the saddle clamps of Sphinx, GPs and the one from the Porta. With the dovetail nested and the two screws snugged nowhere for the scope to go. But on the bright side didn't you want to find room (or an excuse) to take the R200SS anyway:) 


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#34 Nippon

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Posted 30 July 2020 - 09:33 PM

Oh and I meant to mention. I've taken a lot of aluminum lens cells and focusers off aluminum tubes. Most of them Vixen's by the way. Any way they always seem to screw back on a little further. I think it is because the unscrewing and screwing back polishes the threads a little bit making them smoother so they screw in a little more with the same torque.



#35 Bowlerhat

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Posted 30 July 2020 - 10:21 PM

Yes, it is that same scope. I don't see any extended cracks but I'm still concerned. I may be taking the R200SS instead, it will be a nice first run of the SXD2 mount at a darker sky location. We still haven't decided where and when to go.

 

The clamp I have on my older side by side plate is one of those with springs and a small bar that holds the telescope in place (photo on post #1). The dovetail bar is like yours. It happened because I was on the wrong side of the telescope fixing the dew heater strap. Those springs are tricky and tightening in the dark can be deceiving, because although the knob feels tight I had just compressed the springs and not the bar on the previous night. I must have lifted the front of the telescope while fixing the strap and it slid right off. Believe it or not the Baader T2 Zeiss prism didn't suffer a thing, and it was the first to hit the floor.

 

I really like the Vixen dovetail bars and clamps for my small telescopes, they make me feel safe.

 

Bernardo

You can try replacing the clamp bolts with wingnuts, with nylon tipped bolts. I find it much easier to secure it safely.

 

12


#36 Chesterguy1

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Posted 01 August 2020 - 01:09 PM

I feel for you Bernardo. Same thing happened to me a couple of years ago with my beloved V90FL--and mine fell onto concrete! Thought for sure the glass would be broken or shattered. I must have been under a lucky star that night because no damage was done to the lenses or collimation. It did scuff and slightly dent the very end of the dew shield and the diagonal took a significant hit (no EP in it at the time) as did one end of the dovetail. I think the diagonal will have to be replaced as one of the barrels doesn't maintain snugness. Images are still excellent so it didn't mess up the mirror alignment in the diagonal. I have since bought a dual engagement dovetail from ADM, which provides additional reassurance. I also have been avoiding concrete for setup, preferring the grass in my yard.smile.gif

 

Chesterguy


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#37 Nippon

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Posted 01 August 2020 - 01:19 PM

What's a dual engagement dovetail?



#38 dUbeni

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Posted 01 August 2020 - 01:34 PM

Oh and I meant to mention. I've taken a lot of aluminum lens cells and focusers off aluminum tubes. Most of them Vixen's by the way. Any way they always seem to screw back on a little further. I think it is because the unscrewing and screwing back polishes the threads a little bit making them smoother so they screw in a little more with the same torque.

Hi! Nippon, I only remove the cell once a year or every other year for cleaning purposes, and I did put of tape to register the cell position, just a precaution. Something budged a little according to the Cheshire sketch ( post #9), but donadani on post #10 says that I shouldn't be concerned with the Cheshire register.

 

I have no experience evaluating a chipped on glass, so I took a closer picture to obtain some help on how to fix it, and what kind care should I take to keep it from enlarging.

98 Vixen ED80S chip On lens
 
Thanks
Bernardo


#39 Nippon

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Posted 01 August 2020 - 01:42 PM

I wonder if you could use what car windshield people use on windshield cracks. They do have some kind of compound that they can put on a small crack from a stone hit that keeps it from spreading.



#40 eyespy

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Posted 02 August 2020 - 11:29 PM

Hi Nippon,

 

The car windshield system might not work as it requires that a type of suction cup can be attached to the windshield so that a vacuum is created in the crack or chip.  This allows the adhesive that is injected under pressure to be sucked into the crack or chip.

 

Doug.....



#41 Uwe Pilz

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Posted 03 August 2020 - 06:48 AM

Sorry to hear that. I have a TMB Apo 105/650 which slipped out of the clamp. But it let at the EP side. After that, nothing was real destroyed, but the instrument was decollimated heavily. Similar to your instrument, there are tin pieces between the lenses and one of them felt out. I had it to sent to an ptician, and it is in a fine state again.

 

What I recommend with your scope: Try to re-glue the chip. Start with a good kind of tough clear oil, a tiny bit only. You can remove all traces easisly and check first whether the contrast increases. If that is the case, ask in a microscopic forum which kind of cement they  recommend. If you don't trust them: use canada balsam. It may get yellowish in decades, but it is only a very small part of your lens. I think you may repair it so in works flawless.

 

Keep in mind: Oiled lenses are not polished to the real optical need because the oil covers some of the roughness. In the same way the oil / the cement will cover the chip area.


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#42 dUbeni

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Posted 06 August 2020 - 11:12 AM

Thanks guys,

After some thoughts, I've considered that any repair on the lens is a risk, it's better to keep it as is, and maybe make a 72mm mask to cover the chip. Painting it would probably be a risk to the coatings when the time comes for a cleaning job, same thing with specialized glues, I'm not an optician, so I don't know how to properly fix it. I'm afraid of removing the doublet from the cell blush.gif

 

Bernardo




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