80mm long focal length refractor

[savarin]

Thanks Bill but I wish I worked faster.
I'm desperate to start on the binos.

 

[Matthew Gregory]

Gorgeous. How much does the assembly weigh?

 

[Bill Gruby]

Savarin:

Faster is not in the cards for a craftsman such as yourself. It's done when it's done.

"Billy G"

 

[Franko]

What the world needs is more craftsmen such as yourself, Savarin, who take the time required to do a job worth doing.

 

[savarin]

Gorgeous. How much does the assembly weigh?

best guess (bathroom scales, notoriously inaccurate) is around 4Kg (8 lb) it feels around there as well.

What the world needs is more craftsmen such as yourself, Savarin, who take the time required to do a job worth doing.

Thanks Franco much appreciated.

 

[ch2co]

Sir, your craftsmanship and attention to detail are above and beyond anything that I have ever seen. You have a great little lens there, I have a mid '50's Jagers 4" f15 lens that I turned into a scope. For planetary and double star work, this is my go to scope, harder to get around than my C8 cassegrain, but well with the extra effort. Long refractors rule.
What does the interior of your scope look like, baffles, type of antireflective interior tube coating etc?

AMAZING work

CHuck the grumpy old guy

 

[savarin]

Thanks Chuck,
The first baffle is the internal edge of the tube where it screws into the first brass joiner.
This is why the front of the scope has that large black casting to bring the diameters down so the tubes would not cause any vignetting, the second baffle is a thin internal edge in the middle of the second brass joiner, the third baffle is the internal edge of the focusser tube.
Everything inside is painted with a spray can matte black then top coated with thinned Artists carbon black acrylic.
I taped the ends of the tubes, poured the artists paint in and swirled it around to coat every surface, drained it and stood the tubes on end to drain fully and dry.
Of all the matte black paints I experimented with the "Atelier Artists Acrylic" Carbon Black was the flattest and blackest paint I could find.
The paint

Shots where the camera is just sitting pointing down the full length of the scope.
Unpainted inside


Spray can matte only


overcoated with the artists matte

Those two grey dots at 7 oclock were popped bubbles since been smoothed down and re-touched to remove them.
Simple test but looks "black hole" ish to me.

 

[ch2co]

I almost just sent you a series of 3 photos of my latest little refractor tube during blackening, and they look identical to yours. Thanks for the recommendation of the Atelier Artists Acrylic Carbon Black, never came across it before, but I'll have to get a bottle and try it out. John Dobson, of Dobsonian telescope fame, used flat black paint that he mixed sawdust into to get a very black and rough non reflective finish, a real mess, but it works great! Keep up the great work. Let me know how it works when you get around to actually observing with it.

CHuck the grumpy old guy

 

[savarin]

My experiments were very interesting.
Some paints were very black when dead on but turned shiny grey at a glancing angle.
What was very surprising was the ones that looked a shiny grey dead on turned very black at glancing angles.
What paint did you use?

 

[savarin]

I had a re-think regarding the end cap, prising it off by inserting your fingernails into the gap just didnt seem right so I made a knob.



Hmm, large finger print.
Easy to pop off now.
Now searching for some small stainless clips and chain so it wont get lost.