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hex focuser on ES 127 FCD-100 size

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#1 lowry_pt

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Posted 13 April 2021 - 06:23 PM

Does anyone know the THREAD size for the focuser?  I want to SCREW into the focuser not use the compression rings.

Thank you

 

Dawn



#2 photoracer18

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Posted 13 April 2021 - 06:42 PM

You mean the thread size that is under the compression cap? Likely either 63mm or 68mm as those are the two most common threads. I know Moonlite uses 68mm and Starlight uses both depending on focuser size.  I know Stellarvue uses 63mm on every focuser up to and including 2.5" and I think WO does also. Best way is to find out if the maker has their own reducers and flatteners as FF and APS-C ones usually screw into the top of the focuser with the cap removed.



#3 TrustyChords

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Posted 13 April 2021 - 06:48 PM

You mean the thread size that is under the compression cap? Likely either 63mm or 68mm as those are the two most common threads. I know Moonlite uses 68mm and Starlight uses both depending on focuser size.  I know Stellarvue uses 63mm on every focuser up to and including 2.5" and I think WO does also. Best way is to find out if the maker has their own reducers and flatteners as FF and APS-C ones usually screw into the top of the focuser with the cap removed.

My calipers measured about 67.5mm male thread diameter on my ES127 2.5" hex focuser, so I'd go with the 68mm measurement. Note: my calipers are not the most accurate to the mm.


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#4 NUMBER26

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Posted 06 May 2021 - 12:52 PM

For ES127 FD100 CF I screw in at 68mm. Note that the threading on the tube was poor and it messed up. I have had to return the draw tube for replacement.

So take care. I believe the issue was caused by the poor quality extenders that came with the scope. I have replaced them with others from Baader. I needed about 127mm to help get back focus for the camera!




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