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View Full Version here: : ZWO OAG, EFW and 178MM-cool


GOTO
12-09-2017, 04:03 PM
Hi all,

I hope someone can shed some light on this for me please?

http://i39.photobucket.com/albums/e185/Tokyo1989/IMG_3395_zpsyiqa7ubj.jpg

When I connect the EFW to the OAG the prism is at an angle ~40degreees to the CMOS chip but in every picture I see of the setup it is orthogonal.

Ive included a second image to show the rather odd angles involved from a greater distance.

http://i39.photobucket.com/albums/e185/Tokyo1989/IMG_3397_zpsf4iqi63i.jpg

I would have thought everything should have been in the same plane?

Cheers and thanks
Geoff

PS Sorry I'm not sure why the photos show up in the preview but not the post itself?

GOTO
14-09-2017, 05:20 AM
Has anyone used a ZWO OAG with a ZWO EFW please?
Cheers
Geoff

Bart
14-09-2017, 07:19 AM
What are the three larger thumb screws at the back of the oag? Can they be loosened and the OAG rotated to line up? :shrug:

toc
14-09-2017, 07:41 AM
That is exactly what you need to do - I have the same OAG and filter wheel.

AstroApprentice
14-09-2017, 09:47 AM
The three thumb screws lock against the projections of the T2 insert (#3) or the M48 insert (#4), depending on which one your setup needs. Loosening the screws gives you some lateral movement for alignment, but it is limited by the projection width ie if you rotate too far the screws will not be in contact with anything.
Perhaps you need to add a rotating ring?


https://www.highpointscientific.com/media/catalog/product/cache/image/745x/9df78eab33525d08d6e5fb8d27136e95/z/w/zwo_oag_components.jpg

GOTO
14-09-2017, 08:07 PM
Thanks guys but yes the prongs on the #3 and #4 inserts shown in Jason's post above prevent the AOG from being rotated. Very curious but yes it looks like a roasting ring of some sort.
Cheers
Geoff

simon_rl
15-09-2017, 09:00 PM
Hi Geoff,
I have the same EFW and OAG and EFW. I had the same issue and used the adapter in the below link to resolve this issue. I have also added a photo for reference.

By the way the 3 prong adapters will give you about 15 degrees of adjustment. I just used the adapter to get close and then adjusted the on the prongs to get exact alignment.

https://www.bintel.com.au/product/bintel-t-thread-spacer-with-locking-ring/

GOTO
15-09-2017, 09:52 PM
Thank you Simon, guess where I'm going tomorrow to get one of those rings:)
Cheers
Geoff

simon_rl
16-09-2017, 03:32 PM
Your:welcome: