Adjustable T2 adapter

[philjay]

As part of my F4.5 ED80 project I've decided to take the plunge and make an adjustable spacer to get the reducer to chip distance right.

Never been too successful with spacers and reducers in the past that's why I bought a WO Mk4 adjustable one when I had my FLT, so Im gonna try and do this scientifically.

I have also been shying away from screw cutting fine threads like T2 on the lathe and this is was a good exercise in relearning screw cutting. Ive done Whit and big M10 and 15 stuff but nowt as fine as 0.75 pitch for the 42 mm T2.

 

So a few hours on the lathe saw me successfully cutting the external thread

Then the internal thread, which was great fun, the marks on the ali are from where it flew out of the chuck and bounced across the garage floor, took too deep a cut when boring out and didn't have the chuck rammed down tight as I didn't want to deform the tube

The internal thread bit didn't quite work out as I had intended so I had to stack a couple of extra T2 spacers to get distances. Plus the thread is dog rough but for a 1st go its fine.

I then flat blacked the interior in the light path, I will flock this I reckon before using it in anger.

Assembled, the adapter can be screwed in or out to get the correct spacing for the 55mm required on the reducer. The Atik has 13.5mm back focus so 55-13.5 = 41.5 between face of camera and face of spacer, see last pic.

 

In theory it should work. If it don't Im not too fussed as Ive cut my teeth with fine screw cutting on my lathe, see what I did there

 

Also you can buy these made by Baader for 47 ish notes but wheres the fun in that?

 

 

 

Edited November 27, 2016 by philjay

[BAZ]

Looks fine to me, Ali is a bugger to cut threads in at the best of times. If it works that's all that matters.

[philjay]

External threads were really smooth but the internal are a bit rough, think I was taking too much out at a time. Problem is with internal threads you cant see whats going on. The engagement is a bit sloppy but the black locking ring sorts that out, once the distance is adjusted the ring locks things up nice and tight.

I may give it another go sometime soon for more lathe practice.

 

[+Ibbo]

could be chatter as well mines was a swine till I managed to get most of the movement out of the crossslide.

[Stephen]

Nice piece of engineering Phil