On Fri, 03 Feb 2006 14:02:24 -0600, Don Foreman
wrote:

On Fri, 03 Feb 2006 09:22:19 -0800, "T.Alan Kraus"
wrote:

Don Foreman wrote:
I made a little metal crank to replace a broken one on a lathe.

http://users.goldengate.net/~dforeman/crank/

Beautiful work! how did you shape the handle?

T.Alan

Freehand, on the lathe. Turned a little of it, did the rest with file
and strip abrasive paper. It may sound tedious but in fact it only
takes a few minutes, particularly with brass.

Shoulda made it bigger, oh well.

I wasn't quite clear here. The handle was made in two parts. One part
is the ball and stem that joins the hub. I made the balls on a mill
with a boring head and tilted indexing head. Then I drilled the
little ball .312 x about .200 deep (2-flute end mill, flat bottomed
hole), made the little perpendicular handle freehand, and
silverbrazed a little turned stud on the end of the handle into the
hole in the ball.

Lesson learned: clamp lightly before brazing. (I just used gravity)
The air in the hole must have expanded and pushed it out a bit before
the brazing alloy froze. That's why the fillet isn't perfectly
smooth. I didn't have that problem with the other two joints perhaps
because they didn't fit as snugly or there was a route for trapped
air (or steam from flux) to escape.

BTW, re recent discussions of propane vs O/A for silverbrazing: The
two joints on opposite sides of the 3/4" dia hub were made with the
same brazing material (Easy-Flo 45) at different times. The
concentrated heat of O/A allowed me to have the second joint made
before the other side of the hub got hot enough to soften the previous
joint. Can't do that with propane, gotta use different brazing
materials of different melting points.