Cheap alternative to finder guider rings

[Jonk]

I had thought of buying some ADM or other finder rings for the Skywatcher 50mm finder to be used as a lighter, more compact guidescope.

Davey-T suggested pipe clips, so I found these on ebay and at less than a tenner for 2, I bought them.

I also bought a small dovetail bar from the SGL classifieds, and 2 x 10mm stainless hex bolts.

The rings are really strong as they have rubber covers, but these could be removed if necessary.

I bought a finder guider to c-mount adaptor for the DMK camera and hey presto - a very light and cheap guidescope set up.

 

This weighs less than 1kg.

Compared to the ST80 which is nearly double (the camera wasn't attached either).

So, hopefully it works fine (it should do!), I'll have eliminated some flexure and weight.

Thanks to 2 people - Dave for the rings suggestion and Olly for some advice I read a while ago "just bolt it down".

Total cost something like this:

Rings - £8.10

Bolts - £2.00

C-Mount Adaptor - £30

Dovetail - £13.

Total on the bits - <£55.

Finder rings alone would cost more than this and they don't appear to be as sturdy.

Camera and scope I already had.

[hobsey]

Nice to see someone else using this idea.

I remember posting about using these at the back end of 2014 under the title 'poor man's guide scope rings'

[Jonk]

I suppose I would have found it if I had searched exactly for that!

Not that I'm poor or a cheapskate, but I like value for money!

Pipe clamps, will hold pipes or tubes - a scope is a pipe or tube...voila!

[hobsey]

I was poor at the time and terrible at thinking up titles for posts, hence the really bad one that won't come up in forum searches.

[Moonshane]

On a similar vane, I bought these http://www.ebay.co.uk/itm/131340161087?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[Stu]

Munsen rings work very well for this sort of thing. I used a pair to mount my Carton 60 on a dovetail, worked beautifully.

http://www.ebay.co.uk/bhp/munsen-rings

[Jonk]

Yes, that's exactly what they are, rubber lined.

[Jonk]

1st test of new finder guider successful!

Set up in the kitchen with my new hubble artificial star on a tree at the bottom of the garden, about 15m / 50ft away.

PHD picks up the 'stars' ok so proves focus etc.

 

Here's what the artificial star looks like: Canon 6D, 10 seconds, iso 1600, f10, 400mm.

Once it's out on the mount properly, Polaris will get a good look first as it moves the least, then if that all works well, hopefully onto some guiding tests.

Hopefully the move from ST80 to this will be worth it.

I think it will.

 

 

[StuartJPP]

Looks good to me...I am always interested in other people's ideas, especially when it comes to weight reduction. Out of interest what is the focal length of the 50mm finder scope? I read somewhere that it is 175mm, is this correct?

I use the QHYCCD miniGuideScope and the QHY5L-II-M, f/4.3 @130mm, quite happy with it on the few occasions I have been able to use it. Total weight is less than 450g including camera, scope, rings and clamp.

 

 

[Jonk]

Looks nice. I don't know the fl or fr of the 50mm finder, lots of different answers depending where you look.

They all appear to be  around the 200mm mark.

[StuartJPP]

Thanks...that is what I found...circa 170-200mm...

I used to use a 200mm lens as a guider and there doesn't seem to be much difference between it and the 130mm scope in use.