A Lathe Crank Mandrel
I saw the plans for Chris Heapy's
lathe mandrel handle, and decided it looked useful, and not terribly difficult to make.
I changed the OD of the mandrel to suit the ID of the Hendey's spindle, and the cone was made
larger to compensate. An archived discussion on RCM
indicated that a 25deg. included angle would work better than Chris's 20deg. so I went with
that. It doesn't seem to have made a large difference, I'm guessing due to the as-turned surfaces
on my tapers not sliding as smoothly as they might, it still requires a light tap on the end of
the rod to unseat. I did not include the retaining setscrew or the alignment pin in the cone,
and it does not seem to need them.
Since I don't have a mill, the mandrel was squared up for the crank with a few passes on the bench
grinder, then filed to final fit. I cut a groove at the end of the expanding section, and drilled 1/8"
holes in the groove for the ends of the (hack) saw cuts. My thinking was that this would make it
easier for the expanding section to open up against the spindle ID, and the holes would keep cracks
from forming at the ends of the cuts.
I don't show the cone separated from the rod since I didn't get the threads cut terribly straight
on that end of the rod (I used a die), so I jammed the cone on and then trued it up "in situ", and
I don't want to disassemble it again in fear of messing it up. For the other end, I tried single
pointing the threads (my first), and while they weren't a perfect fit, they cleaned up OK with a die
and are much straighter.
At some point, I will make a nice knurled nut for it like Chris has on his.
The parts...
...assembled...
...and mounted in place.
Home
© 2004 Glenn S. Lyford, all trademarks etcetera property of their respective owners.