I was going to make a custom larger crank handle with a collet-type grip on the rear of the spindle just behind where the draw bar slides in. As I was designing this it dawned on me that antique sewing machines had some beautiful hand wheels that I could adapt for this purpose.
|hand wheel adapted for the watchmakers lathe|
I machined off the protruding collar on the inside of the cast iron hand wheel as well as reduced some weight by removing material off the back. This also served to shape a broad flat to mate the adapter to.
|Removing collar from hand wheel|
I set about making the brass and steel adapter to grip the spindle.
|Machining brass adaptor collar for hand wheel|
|Drilling collet retaining screw holes for brass hand wheel adaptor|
|Milling hand wheel cap screw recesses for brass adaptor|
|machining the pressure collet|
|Setting up the cross slide and machining head to drill exact holes|
|Close up machining holes|
|Installing hand wheel adaptor collar|
|tightening hand wheel adaptor collar set screws|
|All parts for adapted hand wheel|
|hand wheel mounted to lathe spindle with brass adaptor|
|Hand wheel showing flange of inner compression steel collet|
|Hand wheel with draw bar in place|
I mounted the hand wheel to test how well it gripped and just for grins, I ran the lathe. It spun true and vibration free!
|Fully functioning hand wheel/flywheel mounted on watchmakers lathe|
What I didn't expect was the very useful flywheel effect that keeping the hand wheel mounted for other operations would have. It dramatically increased the depth of cut I was able to take without slowing the lathe and additionally, reduced chatter and vibration on a number of other milling operations since mounting the hand wheel. It's also extremely pleasant to hold and use for all kinds of positioning tasks and the spokes give great leverage.
As an update to this post, here's a video using the hand wheel for doing manual tapping of a part held in the 3 jaw chuck. The operation was almost effortless and the control and sensitivity is very high.