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Shaun_Astro

Refractor delivered over fence... Possible damage.

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I left a note on my door stating there is a storage box by my gate, which I left unlocked. 

I came home to find my ar90 had been thrown/dropped over the gate. 

I see the lens assembly is in the dew shield and it doesn't seem to be straight over the tube assembly.

 

I just looked at the clouds and sun, it seems OK. It doesn't look right in the scope though, there is no way to collimate it apparently, this is a used version. What do you think? 

 

 

IMG_20201020_143752.jpg

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If the views through it look ok, it probably is.  Difficult to tell the mechanical alignment from close up, a photo showing the whole telescope length would be helpful in this respect.      🙂

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Put a claim in against delivery company for a new one or get funds back from seller it’s their courier 

Edited by bottletopburly

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It's used, was a good price and there are no others available.  It does look a tad wonky which worries me. 

I'll could check the collimation of the lens against a star next clear night, and if it passes I'll keep it I think. Is there a certain way to check or just see how the difference of in and out focused diffraction rings are circular or lopsided. 

 

Here is the sun through it just a minute ago. Looks OK to me. 

IMG_20201020_144050_604.jpg

IMG_20201020_151552.jpg

IMG_20201020_151541.jpg

Edited by Shaun_Astro

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That doesn't look right, definitely not straight..send it back!

Dave

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Looks like the objective cell has been knocked so that it's no longer properly aligned with the tube. This may well have tilted the objective as well.

If you have a cheshire eyepiece you can check this. If not then a star test will show it as non-concentric diffraction rings around a star (Polaris is a good one) either side of sharp focus.

You could try unscrewing the objective cell / dew shield assembly from the top of the scope tube then screwing it carefully back on so that it is square with the top of the tube.

Awful way to deliver a scope :sad:

 

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Yes it seems it is off a lot! I tried to unscrew the lens, it's either glued or stuck. 

 

 

 

Why would they throw it over a gate when I put in a note to put it into a storage box. 

IMG_20201020_153505.jpg

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With bouncing the laser off a mirror back  square into the focuser... 

 

 

 

IMG_20201020_154153.jpg

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If it is like other refractors in the Bresser range the lens cell is held on by three screws into the tube.

The dew shield is a push fit and can be rotated a bit and pulled off. Then around the rear of the lens cell there are three screws that hold the lens cell and flange in place. Could be the screws are loose or damaged. See if you can remove the screws and check for damage. 

Edited by johninderby
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Just a word of caution that the further you go with investigation/disassembly you may be weakening your case should you appeal against the delivery company.  Your solar image looks fine, although hard to judge focus.  I wonder if it is just the dew shield which has been knocked out of alignment. Good luck with it Shaun, it looks otherwise to be a fine refractor. 

 

Jim 

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As others suggest it could just be the dew shield that had been knocked offline and the optics are fine.

I would flag up the issue to the seller and also do a star test at x200 to check the alignment of the optics

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The dew shield just being a push fit is easily knocked put of line but easily re-seated.

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The dewcap or even the objective cell does look to be skewed.  I actually have one of these, the dewcap does pull off revealing the screws that secure the objective cell.  I would loosen these and then press the cell into contact with the main tube and then retightened in position.  I think the offset laser spot is more likely to be due to the focuser end being out of square, this can be corrected by the same method as that of the objective.         🙂    

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Yes the optics seem great.  Lens is about 1/4 the way up the dew shield as shown, and it doesn't seem to actually have a lens cell per se. It's fixed into the dew shield, which is strange!

The dewshield assembly is absolutely stuck fast. In every other refactor you can unscrew it or pull it off, but not in this case.

This this might be the R&P focuser out of collimation, but there's no way to adjust that either! 

I've contacted bresser and asked if there is a way to fix it my end or they can arrange for UPS to sort out their mess.

Edited by Shaun_Astro

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3 minutes ago, Peter Drew said:

The dewcap or even the objective cell does look to be skewed.  I actually have one of these, the dewcap does pull off revealing the screws that secure the objective cell.  I would loosen these and then press the cell into contact with the main tube and then retightened in position.  I think the offset laser spot is more likely to be due to the focuser end being out of square, this can be corrected by the same method as that of the objective.         🙂    

The dewcap or the dew shield?

How do you collimate the focuser, it seems to have 3 screws holding it in place, and none to adjust it.

Edited by Shaun_Astro

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You have my sympathy.  I've had the same fun with deliveries of bass guitars which couriers seem quite adept at damaging even when packed in hard shell cases and cardboard.  Contact the seller, he/she has the contract with the courier (I assume) and should be able to claim the insurance (hopefully taken). 

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The dew shield will pull off but can be very stubborn. Found rotating the shield a bit breaks it loose most times.

Easier with one oerson to hold the tube while the other wiggles and twists the dew shield.

Edited by johninderby
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39 minutes ago, Shaun_Astro said:

Why would they throw it over a gate when I put in a note to put it into a storage box. 

May not have been able to read English, not a criticism, just a fact of life.

Dave

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Aha! No luck with the dew shield. But I may have found the issue. The eyepiece holder clamp was either knocked wonky or screwed on poorly. It was at an angle and off the threads. 

I've straightened it up and it seems to be reasonably in collimation now. The image shows after in took it off and screwed it back on again. 

I thought the dew shield didn't look wonky enough to cause that much of an issue. I assume the divergence from the centre now is due to that or poor collimation of the focuser. 

 

 

IMG_20201020_162343.jpg

IMG_20201020_162301.jpg

Edited by Shaun_Astro

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That should be plenty good enough for the focuser alignment on a F10 refractor.  It still doesn't guarantee that the objective cell is square to the main tube.  This would be obvious in a star test eventually.  As long as nothing is actually broken, all else is fixable.      🙂

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Shaun sorry to read this especially as you gave proper instructions. Hopefully, it will all work okay in the end.

It is worrying because there have been many reports on damaged scopes/cases by poor delivery arrangements.

 

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3 hours ago, dweller25 said:

@Shaun_Astro
 

Result 😀

Straightening the dew shield may improve your laser test even more.....

It iterally won't budge a single mm. I tried rotating it, it's jammed in place or glued. 

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ahh the old FBH trick, shifts most things 😄

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