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hadyn42

SW ED80 lens cell loose?

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Hello Guys

I hope all of you out there are keeping safe and well.

Please can someone help if possible?

Today I removed the standard focuser on my ED80 and before fitting the new one I thought I would just giving the telescope tube a bit of a wipe down to remove any dirt etc on the outside. When I was turning the telescope around on my worktop I noticed a small rattle coming from front end of the tube. Bearing in mind that there were no fittings attached to the scope at the time. I really do think that the lens/lenses were loose and it did sound like glass on glass etc.

Can anyone tell me is there a away to tighten the lens / lenses and if  so are there are any tools out there that I could use, also can you include a link to them and of course can this job be done without having to send my telescope away please?

Kind regards,

Hadyn - IOM

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If the front end is like the 72 ED then the front has a small retaining ring that holds the lens cell in place. I would expect that all it does is push the cell itself down against some circular stop ring in the OTA body. And has no real or great impact on the lenses themselves. I say none as if you managed to really make the effort no doubt you could have some effect.

The ring has 2 slots diagonally opposite on the ring. The best you can do is get some illumination and a long narrow bladed screwdriver insert the blade carefully into a slot and carefully and gently drag it round clockwise to tighten it up.

I say "long" as on the 72ED the dew shield seems fixed so you need something long enough to cover the length of that. If the 80ED dew shield is removable then remove it as it would make the task immensly easier.

Canot think of an available tool for the task, or at least one specifically. I would think that Synta have some items made for the task. Also they are likely tightened when the dew shield is not in place.

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The ring that holds the objective in place is shown below - the one with two holes in it. You can make a tool to tighten it slightly with a piece of wood with two slim nails though it.

It only needs to be touching the objective enough to stop the rattle though. It should not be tight at all.

Dust on inside lens of new SW 80ED - Refractors - Cloudy Nights

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How loose is it?

The glass needs to expand and contract so a bit of movement is needed.

There is a danger of pinching the objective by overtightening so beware.

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Hello Guys

Thank you all for your answers.

I think I will leave it well alone guys for the moment and check it again under cooler conditions!

Kind regards,

Hadyn = IOM

 

 

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1 hour ago, philj said:

How loose is it?

The glass needs to expand and contract so a bit of movement is needed.

There is a danger of pinching the objective by overtightening so beware.

Hi Philj

When I hold the telescope vertical with focuser end towards the ground and give the scope a sharp shake up and down I can hear the clunking of glass.

As I mentioned, I think I will wait until late evening and try when its much cooler outside, does that sound like a good idea please/

Kind regards,

Hadyn - IOM

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On 20/06/2020 at 18:32, hadyn42 said:

Hi Philj

When I hold the telescope vertical with focuser end towards the ground and give the scope a sharp shake up and down I can hear the clunking of glass.

As I mentioned, I think I will wait until late evening and try when its much cooler outside, does that sound like a good idea please/

Kind regards,

Hadyn - IOM

I would check the retaining ring and if it is loose, at least get in hand tight by rotating with a finger - you don't want to give it a good shake and have a lens or two fall out! My Edge 8" reducer made a clunking noise similar to what you are describing just before it fell apart in my hands.

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