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polar orfice 90* to scope?

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#1 dragonslayer1

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Posted 24 June 2013 - 09:45 AM

I have a CG-5 ASGT and was just checking the polar align on it. The question I have is that when polar scope tube is aligned for scope the mount for OTA is sitting 90* off from being in same alignment as polar scope would be? Is this normal? will try to attatch a picture, thank you
Kasey

#2 DaveJ

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Posted 24 June 2013 - 10:42 AM

I have a CG-5 ASGT and was just checking the polar align on it. The question I have is that when polar scope tube is aligned for scope the mount for OTA is sitting 90* off from being in same alignment as polar scope would be? Is this normal? will try to attatch a picture, thank you


Yup. Perfectly normal. All German equatorial mounts seem to be this way - at least the ones with polar finder capability. My old LXD650 and Losmandy G-11, my current CGE and CGEM DX are that way, too. Why? No idea! :shrug:

Edit: Oops! My bad. The CGE is NOT polar finder capable and, hence, does NOT have the bore-hole. :foreheadslap:

#3 jrcrilly

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Posted 24 June 2013 - 10:55 AM

Why? No idea! :shrug:


That arrangement was adopted in pre-SCT days so everyone had long optical tubes. Picture trying to get to the polar scope with a long refractor in the way... :foreheadslap:

#4 dragonslayer1

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Posted 24 June 2013 - 11:09 AM

I see, just wondered if my mount was assembled wrong :question:,, The long scope is a good explination :foreheadslap: thank you, Kasey

#5 mclewis1

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Posted 24 June 2013 - 01:05 PM

Oops! My bad. The CGE is NOT polar finder capable and, hence, does NOT have the bore-hole.

Dave, Actually there is/was a polar scope for the CGE. You're right there's no bore-hole but this polar scope fits on the outside. It was never a very popular option and is now completely unnecessary with the All Star polar alignment routine in the hand controller.

#6 EFT

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Posted 25 June 2013 - 09:17 AM

Yup. Perfectly normal. All German equatorial mounts seem to be this way - at least the ones with polar finder capability. My old LXD650 and Losmandy G-11, my current CGE and CGEM DX are that way, too. Why? No idea! :shrug:


The reason for this is actually so that you can rotate the RA axis to get the polar scope in the correct position without the OTA hitting the tripod. If the OTA is located parallel to the RA housing, then you can only rotate the RA to about 30 degrees below the horizontal position without contacting the tripod (further if you have a pier). If you have a rotating polar scope this is not an issue, but most polar scopes do not rotate without loosening them and then loosing their alignment. Thus, you turn the OTA 90 degrees so that in most cases you can rotate the RA and polar scope 360 degrees.

#7 dragonslayer1

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Posted 25 June 2013 - 10:46 AM

Yep got it now :bow:, am using a C9.25 on mine so length of scope never entered my mind,,, It just looked wierd, seemd to be at odds with one would think it should look like :question: So much for thinking, LOL
Kasey






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