DIY guide scope

[Mick1]

I've read articles and watched vid's on you tube on how to set up a guide scope with all the required equipment and do it on the cheep.
I see that a 9x50 finder scope is the scope that is used. Would it be possible or feasible to use a 6x30, simply because I have one that is not being used and I would like to do something with it.

[OzEclipse]

Mick,

Optically, there is no reason why it won't work.

You'll lose a bit more than 1 magnitude on the faintest guide stars you can image and a 6x30 tube and brackets isn't as strong as a 9x50 so you'll need to watch for flexure.

Joe

[Mick1]

Joe,
When I purchased my ota it was supplied with a 6x30 finder, the companies web site stated that it is sold with a 9x50 finder. When I questioned why I received my a 6x30 the business promptly sent me out a 9x50 finder scope.
I now have a 6x30 finder scope doing nothing and I would like to utilize it some how.
I was thinking of buying a dual dove tail finder scope type mount from Bintel or somewhere like that and mount them both on my main 102x1000 refractor.

[ZeroID]

The 9 x 50 would probably make a better guide scope having more aperture. A 6 x 30 is pretty undersized in more ways than one as Joe says.
Not knowing what the rest of your setup is makes it hard to suggest best guiding solutions. On equatorial mounts just tracking is good enough for visual. Astrophotography requires guiding to manage various mechanical and alignment errors for long exposures. Even planetary or lunar video can be done just with tracking.

[Rkonrad]

6X 30 is small but there are good 6x30 finders , on my Tasco 10TE its a great finder almost as good as the 9x50 (similat FOV) on my 150 Mac , a proper Achromat with the correct baffle works great , but some of the modern ones are really bad , take it apart to see if it has a good cemented doublet and a large baffle

[jimmyh1555]

I would put that 6 x 30 in the next jumble sale. They are not good for anything apart from maybe taking apart and using the lens as a magnifying glass:P:lol:

[Rkonrad]

Yes modern 6x30 finders are bad but remember in the 60's that was the best finder and was made as a proper scope

[ZeroID]

Still insufficient aperture and field to make a good guide scope as the OP asks.

[Rkonrad]

Probably you are correct but worth a try ans they are cheap

[traveller]

Mick, I suggest you do it once and do it right by using a 8/9x50mm finder. Besides the small aperture , the other issue you need to consider is attachment of the guide camera.
I made my own guidescope using a 50mm straight through finder. I unscrewed the rear "eyepiece" off, used a drimmel to slightly thin out the inner sides of the 50mm OTA tube.
This will now be just allow for a 2" - 1.25" self centering adapter to be pushed into the OTA (use a bit of silicon to make a waterproof fit). Bintel used to sell those adapters, they are like this https://www.telescope.com/Orion-2-to-125-Precision-Centering-Adapter/p/102820.uts
This will allow you to use a 1.25" barreled guide camera like Loadestar or QHYII-5 (see photo below), then you are all set to go!
Cheers
Bo