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floastro

My ASA 12"N Focuser modification

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Hi guys,

After my TeleVue NP101is ( http://www.poigetdigitalpics.com/photo-equipment3.html ), i decided to change the focuser of my ASA 12" newtonian reflector. The native focuser was the ASA OK3-Z for heavy imaging train. But i had several big problems with it, mechanical problems, impossible to do automatic focusing, backlash..... etc. It was impossible to me to use the huge KAF-16803 chip of my Moravian G4-16000. And with the mechanical problems, i had a shifting of my imaging train inside the OK3-Z focuser and the CCD chip was not aligned with the optics even if my collimation was great with the CATSEYE kit.

After several nights of tests and when i found the real problem, i decided to change the focuser by a high-end focuser : a low profile focuser.

 

2 choices : one FLI ATLAS as on my TeleVue but very expensive or the new low profile focuser on the market released by OPTEC, the TCF LEO. The LEO specifications are the same that the FLI except for the price, the LEO is 50% cheaper.

After a few mails with Jeff from OPTEC, i ordered their last version, the Split-Clamp, of the LEO designed for heavy Wynne 3" corrector for newtonian.

I calculated the effective length for the adapter installed between the ASA OTA and the LEO focuser. The adapter has been made by Precise Parts in Florida.

 

The last weekend, with the Full Moon, i installed and tested the OPTEC TCF LEO on the ASA 12"N f/3.62 .

 

All is OK now with a high precision Auto focusing. I can use my 16803 chip now on my newtonian.

 

A few images of the mounting :

 

20190723_170920_FB.jpg.ed82d49f43626843da8f1c7a1d3668dd.jpg

 

20190723_171233_FB.jpg.041f285e6c46628cbdb5553a58e32552.jpg

 

20190723_170812_FB.thumb.jpg.742c7914426ba85ca564e547d7ac7d60.jpg

 

 

PSX_20190901_020412.thumb.jpg.e61c6dd8461cc750be3f3f6584c26c13.jpg

 

 

PSX_20190901_020249.thumb.jpg.f2a956749eeeec37a6dc67a70933dc12.jpg

 

 

PSX_20190901_020505.thumb.jpg.d7e4f63407641515b2f729db4f5c0db9.jpg

 

 

20190914_193739-Modifier.thumb.jpg.55c7e7fa2324d73e1a1dbd4d7ed78851.jpg

 

 

ImpressLEO_1.thumb.jpg.1bb9da1cf247914126d00f51be41c0be.jpg

 

ImpressLEO_2.thumb.jpg.8879d57579a9a62001d96cb60e97334c.jpg

 

ImpressLEO_3.thumb.jpg.62e9f9162bcb8cd8392af538186f1473.jpg

 

 

This is a test of 300sec of subexposure taken with the G4-16000 CCD camera / ASA 12"N f/3.62 with its ASA 3" Wynne corrector / OPTEC TCF LEO.

Full 4K x 4K image, no cropped : http://www.poigetdigitalpics.com/Fichiers_Divers/t_NGC7000_RED_[2019_09_14]-001.jpg

 

 

_DSC3347_dxo10-Modifier.thumb.jpg.547c0b919da39b2a86e4e9d61f403e38.jpg

 

 

_DSC3352_dxo10-Modifier.thumb.jpg.55c0452172d2039e1ed0b273471a4c14.jpg

 

 

_DSC3353_dxo10-Modifier.thumb.jpg.86ba6d048732a0483fff36be745bbffa.jpg

 

 

Florent 🙂

Edited by floastro
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Hello, and thank you for sharing the information,

I have the same problem but with my ASA 8N ( from year 2006 ).. and searching also for a solution or a replacement of the focuser.

Cheers

 

Martin

 

image.png.cdcdebc84d2f2626ccba35989eeb3828.png

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12 hours ago, artem said:

Hello, and thank you for sharing the information,

I have the same problem but with my ASA 8N ( from year 2006 ).. and searching also for a solution or a replacement of the focuser.

Cheers

 

Martin

 

image.png.cdcdebc84d2f2626ccba35989eeb3828.png

Hi Martin,

My ASA 12" is from year 2007. The native focuser was a JMI NGF xTn 3" replaced with an ASA OK3-Z. My OK3-Z was catastrophic. The OPTEC LEO is an incredible focuser for imaging.

Florent

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Hi Florent,

Thank you for your answer., my focuser is already partly broken, I must be very patient when I focus + a BAHTINOV, I am now searching for an alternate focuser to exchange the old one..

 Cheers

Martin

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