# DTI Fine Adjustment Holder



## Rob Thule (May 1, 2022)

This holder is half the size of the one I built some years ago. It consists of a flexure made from a truck’s leaf spring incorporating at one end a dovetail clamp and stem at the other. An internal screw jack pushes on a steel ball to flex the joint.

I made it because I needed a compact version and to see if I could still heat treat a spring


----------



## jwmelvin (May 1, 2022)

That’s fabulous! I love flexures. 

The thickness is from the leaf spring? You annealed to machine then hardened? It’s a predictable enough material?

One half of the dovetail is integrated to the flexure body and the other half is separate?

Pressed in pin for the other end?

The flexure looks compressed from the as-cut position. But the screw forces it open. Did you deform to close the gap before hardening?


----------



## Rob Thule (May 1, 2022)

jwmelvin said:


> That’s fabulous! I love flexures.
> 
> The thickness is from the leaf spring? You annealed to machine then hardened? It’s a predictable enough material?
> 
> ...


Thanks 

The main body is from the leaf spring and incorporates one side of the dovetail. The other side is separate as I was not in the mood to make a cutter for something that could easily go south. The pin is machined from the solid.

The material was annealed, machined and polished to reduce stress concentrators. The flexure was compressed and held so, using wire, during hardening. This gave me some more movement given that the flexure's diameter is relatively small. It retained the set after the wire was removed and was then tempered by eye. It's mystery metal so quenching was made in oil to be safe.


----------

