Bino Scope Project

[Brantuk]

Looking forward to seeing this in action for real - lovely job Phil  ?

[catman161]

This looks amazing Phil. Such an awesome build and unbelievable Astro knowledge and skills. 

[philjay]

Managed about 30 minutes in between clouds to try out the bins under darkish skies before the weather moved in again.

 

The aim of this exercise was to see what DSOs looked like in the bins and also to get used to the handling and collimation.

 

Collimation

Even though I collimated the tubes I found the two FOV circles were off resulting in the object to be viewed being in different parts of each scope FOV, this was not right and I traced it down to the mirror diagonal clamps on each prism. Thus tube collimation wasnt shifting which was good but the movement in the clamps meant the eyepiece angles were not the same and this was throwing things out. This was evident in that I could collimate to get good binocular vision at 75x but when wound down to 24x it would be out again. The other week it wasnt doing this, I could collimate at 75x and collimation would stay on whatever mags I used, so I know it can do it.

 

OK so thats the next area to concentrate on ironing out and beefing up.

 

 

 

Handling,

 with the pan and tilt handle, handling was OK but it felt a little odd at first because the bins are offset from the mount, this was no problem with alt and az locks off but if I put a bit of friction on them it felt odd. I think this is just a matter of getting used to it.

 

I fitted a RA finder to help with finding stuff at the zenith but I had the tripod set a bit too high initially so using the finder was a bit fiddly. I lowered the tripod slightly and rotated the finder to a different position and things were a bit more comfortable.

 

Performance.

Collimated on Mars at 75x and this was a nice view. Mars was small but a definite gibbous shape could be seen and the background stars were good. No detail as at 75x it was a bit small plus the atmospherics were turbulent to say the least. I was glad I was in the lee of the house.

 

M45 at 24x. Yep, lovely colour, depth and really bright. The Vixen zooms are not the widest FOV around, I havent built this scope for wide FOV but the cluster fitted just nicely in view. The brighter stars seemed to stand forward of the fainter ones giving a 3d effect.

 

M31. This surprised me because normally this is just an elongated blob in an 80mm in these skies but I was really surprised at it being brighter than expected with 32 and 110 standing out nicely. In the  fuzzy elongated shape of 31 was a clearly identified darker area corresponding to the darker dust lanes, no detail just the indication that this was a dark patch.

 

Double cluster. Found it easily with the finder then had a look through the vixens and was underwhelmed, then looked  up to see a blanket of cloud, I was trying to look through quite a thick layer. I waited for it to disperse then had another look..... Woah!!!! Talk about 3d.

Because the clusters were at the zenith I set a small stool alongside the scope and the eyepieces were at a perfect height for me to just sit and drink the view in. The colours for a start, yellows and the odd hint of orange. Next, just like with M45 the brighter stars stood right out, I just sat there for 10 minutes drinking the view in until it disappeared behind thick cloud. I looked up to see not a single star visible in the sky, game over due to complete cloud cover.

 

OK it was only a short test but I was buzzing, this scope, despite the few snags that still need ironing out is starting to perform. I am really looking forward to testing this properly now.

 

 

[philjay]

Oh just forgot to mention, the views are far brighter than a single ED80 with binoviewer. I know its an obvious point but when committing to a project like this there is always a little niggle in the back of the mind.

[BAZ]

Fantastic! It's defo getting there. 

[Tweedledee]

Lovely report Phil. Sounds like you're really enjoying the views. ? ?

 

You're ironing out all the bugs, so the big bins will be perfect by the time I buy them for the 300 euros we agreed. ?

[philjay]

13 minutes ago, Tweedledee said:

Lovely report Phil. Sounds like you're really enjoying the views. ? ?

 

You're ironing out all the bugs, so the big bins will be perfect by the time I buy them for the 300 euros we agreed. ?

Hmm, I think your 0 key stopped working there Pete ?

[philjay]

A brief update.

The past week or so has been spent sorting toolless alignment adjustment of the tubes on the bracket and beefing up certain areas.

 

The alignment of the tubes is one tube shifts sideways and the other vertically so in the mk1 bracket I just used allen screws to prove that the alignment works, the next step was to make it easy to align, almost one touch. So a bit of head scratching and some compression spring and here is the finalised designs. The lateral adjuster is straightforward, the screw pushes the bar that the OTA is mounted on against a spring plunger. A lock nob under the bracket locks everything up when aligned.

The vertical adjustment was a bit more of a challenge. My mk1 bracket showed that the tube just had to be tilted from the back just a few thou' so it didnt need much in the way of adjustment so I plumped for a thumb wheel which pushes or pulls the back of the tube. It seems to work.

 

 

 

Ive also found a use for my vintage Gitso tripod pan and tilt handle which means you can move the scope without touching the eyepiece and risking collimation shift.

Its all ready for a clean up now and shaving a bit of ali off to reduce weight a touch plus a paint job.

 

 

 

Edited December 18, 2018 by philjay

[+Graham]

Very nice too Phil. 

I love it when a plan comes together. 

[Tweedledee]

Superb looking job Phil. ?

 

Hopefully you have it sorted now.

[Smithysteve]

Excellent report on progress... with you all the way. I enjoyed the wow moments too especially on the double cluster - these things make it all worthwhile! ?

[philjay]

Thanks chaps.

This has been a great project for me and as I said at the beginning I am taking my time. Making one scope is easy cos you only use one eye, making 2 work together is a whole new experience and I knew I would be learning all the way. I remember Peter Drew saying at Kelling he could knock one up in an afternoon but that's because he has years of experience in making them and I'm new to this. So hopefully once Ive sorted what needs to be sorted I could probably do the same ?

 

Im just enjoying doing the project more than anything else, its been awhile since I did an astro project so I dont know what I will do after Ive finished this one, or will I ever finish it?

[philjay]

Just tested the completed toolless adjustment out terrestrially on some barns in the distance, EEEEE luxury ?, silky smooth adjustment, it works a treat. To quote Graham, I love it when a plan comes together.

A major lesson learned here:-

The thing with binoscopes is unless you have super dupa ultra expensive IPD prisms (like the stunning Matsumoto EMS Japanese versions http://ems-bino.com/ems-product-line-english/ that you can get), using the basic IPD prisms will result in collimation discrepancies no matter how careful you are.

The super dupa ones have collimation adjusters on the back of the diagonals so can be easily tuned, so all you need is a dual CNC'd OTA saddle that keeps the tubes parallel and all adjustments is done on the diagonals. However mine / Peter Drews method is alignment in the tubes only so easy one touch adjustment is essential.

Because when swapping eyepieces or even zooming in on the Vixens collimation shifts and you sometimes loose binocular vision, not because the tubes have shifted, its because of the slight discrepancies in the IPD prisms, clamping arrangements etc.   

Also the higher the mag the more critical the collimation, this is called Super Collimation in posh big binocular parlance and costs a bit to have done to your big Taks but is integral with mine ?

[8472]

Ooh this one went completely under my radar.

 

Epic work there, Phil. I can't wait to see in in action at a future meet!