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Eliminating flexure


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Hi, I have a 130pds and I'm using a skywatcher 9x50 finder scope and qhy5. This seems to guide well but I think it could be better.

What I don't like is the finder scope is sat in the original dovetail on the telescope which isn't the most secure of things. It's also impossible to balance now in RA because of the top end weight.

I have a few options I think. 

1. Finding scope rings for the finder scope and bolting it to the top dovetail of my 130pds? I can't seem to find clamshell type rings.

2. Buying an st80 and get rid of the finder scope altogether. The extra weight isn't an issue on the neq6 I don't think.

I will eventually be buying a refractor so I'm hoping whatever I buy will be compatible when I change over. 

Thanks

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I solved the same problem with a couple of these dovetail adapters with guiderings attached

https://www.firstlightoptics.com/adm-vixen-type-v-series/adm_vdpa_adaptor.html

For my 130 Newt, I clamp to the top dovetail, and for a larger scope I actually clamp upside down to the bottom (longer) dovetail.

Makes a huge difference to the balancing.

 

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AndyK93,

It sits pretty square to the scope but no adjustment (or flexure) as I don't use this for finding objects. I have a telerad that I use for visual location of objects but as I only use this scope for imaging most alignment is done through APT GOTO+ which uses plate solving through the main scope.  Works for me with bang on targets centred every time.

Gareth  

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1 hour ago, Garethr said:

AndyK93,

It sits pretty square to the scope but no adjustment (or flexure) as I don't use this for finding objects. I have a telerad that I use for visual location of objects but as I only use this scope for imaging most alignment is done through APT GOTO+ which uses plate solving through the main scope.  Works for me with bang on targets centred every time.

Gareth  

I also have a telrad for lining up roughly and then plate solve. I use my guidescope with sharpcaps polar align routine so wondered if a slight misalignment would mean worse PA. thanks

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Andy

My thoughts were FWIW if the guide scope is parallel to the main scope and aligned along the spine PA will be the same or the difference so small that it wont matter.

I use sharp cap to polar align and don't seem to have issues when guiding.  The graph looks fine even at 1 scale in PHD 

I can only use 600sec subs due to London light pollution but I get what I consider to be good images :happy7:

 

 

HH.jpg

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2 hours ago, Garethr said:

I use sharp cap to polar align and don't seem to have issues when guiding.

Yes, same for me.  That's what I find.   So although in my solution there are guide rings, I only ever use them to remove the guide scope rather than try to align with the main scope.

 

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