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Light-weight apos. A thing of the past?

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#26 Jon Isaacs

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Posted 05 March 2020 - 12:59 AM

He ain't heavy, he's my telescope!

 

Groan.. but a good Groan..  

 

:roflmao:  

 

That was bad.. 

 

Jon


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#27 25585

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Posted 05 March 2020 - 06:25 AM

Its strength that counts. There are smaller carbon fibre OTA telescopes you can buy. Orion do a 66 & 90 for example.



#28 Jon Isaacs

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Posted 05 March 2020 - 07:03 AM

Its strength that counts. There are smaller carbon fibre OTA telescopes you can buy. Orion do a 66 & 90 for example.

 

Not really.. There are very few parts on a telescope that are loaded to point where stress is a factor.  The 1/4-20 bolt that secures a scope to the tripod, it has proof load of over 2000 lbs, in shear, even a cheap bolt in good for over 1000 lbs.  

 

Carbon fiber doesn't save much weight in a small refractor because the only parts that are carbon fiber are the tube and the dew shield, the rest is aluminum.  The focuser, the topic of this discussion, is aluminum.  I calculate that an aluminum tube and dew shield for the 66 mm Orion would weigh about 10 ounces.  There's not much weight to be saved.

 

Jon


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#29 jeffmac

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Posted 06 March 2020 - 11:11 PM

The Vixen 115mm ED doublet weighs in a little over 8 lbs.

#30 Lookitup

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Posted 06 March 2020 - 11:36 PM

There was an error on the specs referencing the ED103. Still at 11 to 13lb the ED155s was the lightest bigger aperture scope I ever had. Tried to buy the Borg 125 to no availability.  The Tak DF won in everyday use due to size and faster cooling.  


Edited by Lookitup, 07 March 2020 - 12:24 AM.


#31 aa6ww

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Posted 08 March 2020 - 04:53 AM

The OTA on my APM 152ED weights about 20 pounds and thats with the big 3.7" focuser. That's half the weight of my friends 6" F8 TMB triplet and at least 10 pounds lighter then my TOA-130.

 

The FS-102 I use to have seems considerably heavier then the current 100 mm Takahashi doublets.

 

I see scopes getting much lighter now then they ever have been. 

 

...Ralph

 

 

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#32 Moatie

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Posted 14 March 2020 - 01:25 AM

The OTA on my APM 152ED weights about 20 pounds and thats with the big 3.7" focuser. That's half the weight of my friends 6" F8 TMB triplet and at least 10 pounds lighter then my TOA-130.

 

The FS-102 I use to have seems considerably heavier then the current 100 mm Takahashi doublets.

 

I see scopes getting much lighter now then they ever have been. 

 

...Ralph

My friend and I used to go out observing.  He had a Tak TAO-130.  It was heavy, and we are old.  My AP 130 Starfire weighed almost half of the Tak refractor, and that was nice as I'm getting older.  Was always curious how AP made the similar scope with so much less weight, and was grateful for it.


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#33 RichA

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Posted 16 March 2020 - 11:57 AM

The OTA on my APM 152ED weights about 20 pounds and thats with the big 3.7" focuser. That's half the weight of my friends 6" F8 TMB triplet and at least 10 pounds lighter then my TOA-130.

 

The FS-102 I use to have seems considerably heavier then the current 100 mm Takahashi doublets.

 

I see scopes getting much lighter now then they ever have been. 

 

...Ralph

I had the FS-102 Tak and it was heavy to a point, but not as bad as some long 4" scopes.  The Vernonscope/AP 92/94mm apo switched the focuser and objective housing partway through production to make it lighter as the originals were untouched 4" Unitron scope focuser and cells.




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