80mm long focal length refractor

[savarin]

Still waiting for the block of ally so I started on the finder scope.
I'm using a doublet from an knackered binocular.

The right hand joiner was already made, one end of the tube was threaded, so today I cut it to length and threaded it, also there is approx 30mm of taper on the inside with a fine thread for anti reflection once its painted matt black.
The centre joiner has three different dia threads, one for the tube, one for the lens cell and one for the lens hood.
I cut a fine thread inside the hood and have sprayed it matt black.
All assembled it looks like this

More polish needed on the hood and tube but the joiners will be gloss black.
You can just see the gaps left for the "O" ring sealing glands so moisture doesnt wick into the tube.

 

[Matthew Gregory]

Such a fantastic project... Love checking in to see your progress.


How'd the jaw operation go?

 

[savarin]

Thanks Matthew, jaw doing fine, they had to go in from the side to remove an old bit of tooth root that kept getting infected.

 

[savarin]

Finder scope finished and looking very nice.
However, I now have a cemented 50mm japanese doublet that may be a better objective but it needs the central tube to be another 15mm longer and a different lens cell. Maybe after its all finished.


At last I can start on the focusser unit.
I couldnt find any 60mm plate but did find some 100mm round.
Now came the hard part, I dont have a mill but need to convert this cylinder to a block.
It wont fit securely in the chuck.
I scribed the block size on the top of the cylinder, drilled the centre and mounted it on the compound in place of the tool post.
I used a rule to align the scribed line with the face of the chuck.

The only tool I could use that had sufficient off set happened to be the Eccentric Engineering diamond tool holder and this proved to be just right held at an angle in the 4 jaw.

about half way through here. as I got closer to the scribed line I just had to make a tiny re-alignment to bring it back to spot on.

Instead of doing the same thing to the other side I mounted it against the chuck jaws as there was just enough room and have started milling the other side. I'm hoping they will be parallel by doing it this way.
The first cuts seem to point this way.

 

[Bill Gruby]

And I thought I was bad, you really put that 9X20 through its comfort zone. Kudos.

"Billy G"

 

[savarin]

And I thought I was bad, you really put that 9X20 through its comfort zone. Kudos.

"Billy G"

Thanks Bill, what is it they say? A mans gotta do?
This old cook really needs a mill. (or should that be kook)

 

[JimDawson]

Very creative setup, I love it. Nice work also.

 

[brino]

I'm hoping they will be parallel by doing it this way.

It certainly should be.

Savarin,

You always amaze me with your out-of-the-box approach to problems. I know I have said it to you before but you manage more with a lathe than others with a shop full of tools.

I really enjoy your posts.
Thanks for sharing!

-brino

 

[Franko]

I agree with brino. I am very impressed.

 

[savarin]

Gee guys, at this rate my head wont fit through the door.
Many thanks.