Spindle crank handle for ww lathe

There are a number of operations on the lathe that either require, or I want to use, hand rotation of the spindle. Threading with a die, a tap or a thread cutting attachment to name a few. I also want to be able to groove certain fine parts I'm working on around only part of their circumference.

To do this I needed a crank handle that was easy to mount quickly, very stable and allowed for precise direct rotation of the spindle. The solution was to design one from the ground up.

Here are the cad renderings of the parts. The back of the handle design has a recess and key to accept a reverse collet-like tip that will insert directly into the end of the hollow draw bar and expand locking the handle into place. I also wanted it to be beautiful so I had some fun in the design, especially with the metal basket weave grip.

Drawbar mounted crank handle in place on WW headstock

crank handle cad rear view

Crank handle cad 3/4 view

Crank handle cad front view
I sent the files off to Shapeways and the parts came back looking great. They always have a casting-like grainy texture to them and I like the contrast to the machined surfaces and parts. The grip is made in black stainless steel and also came out great.

All parts for the crank handle

the casting for the crank showing the key

If you look closely you can see the very fine cuts in the barrel of the expanding mounting shaft

crank with expanding connector in place

The center shaft is threaded and the large nut pulls it into the expanding barrel causing it to grip the inside surface of the draw bar tube.

grip assemble on crank

crank handle fully assemble
cast grip shaft and retaining nut

I really like the way the little grip turned out and it feels great in the hand when you are using it. Great finger purchase and the inside is machined out to an exact but free spinning fit over the mounting shaft. Feels very high precision.

grip with basket weave design in black stainless steel
The mounting shaft threads fit into the threaded and stepped recess at the top of the crank lever and the nut acts as a locking nut to prevent it from backing out.

free rotating grip assembled

It slides in nicely and firmly grips the draw bar.

Inserting crank handle expanding shaft into the drawbar

crank in place on lathe headstock

crank mounted on lathe

crank in place
My next project is already underway. I'm designing a custom spindle lock that mounts to the WW headstock non-destructively.
Cheers, KM

1 comment:

  1. Very nice and useful design!
    Thanks for sharing.


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