On Sat, 13 May 2006 07:46:59 -0700, Eric R Snow
wrote:


see http://www.mcduffee-associates.us/ma...ndle_crank.htm
to see a hand crank we manufactured in class for exactly this
purpose.


Greetings George,
If I have to do many pieces then the CNC lathe does it for me. But the
real reason for not using a slow spindle speed is because of finish.
Many materials will not machine well at low surface speeds. My other
option is to buy a Hardinge HLVH. Which I'm considering. But the
Hardinges doesn't have the 14 inch swing. On top of that, this lathe
should have this feature anyway. In fact, all lathes should be made
this way. My opinion of course isn't worth anything though...
Eric


The HLV-H will thread easily and comfortably up to about 1000 rpm,
older machines may need a bit of clearance if the half nuts are worn.

Many machines can be fitted with a fast release on the half nut if its
a half nut threading style machine..which the Hardinge is not.

Indeed..I have to run some materials up near that 1000 rpm range to
get decent threads with no chatter marks, but until you are
comfortable with using an HLV-H...its a heart in mouth experience
watching that sucker heading for the spindle at high speeds.

CNC threads so quick, its not much of an issue as each cycle happens
so fast you really dont see it, much of the time.

Gunner



The aim of untold millions is to be free to do exactly as they choose
and for someone else to pay when things go wrong.

In the past few decades, a peculiar and distinctive psychology
has emerged in England. Gone are the civility, sturdy independence,
and admirable stoicism that carried the English through the war years
.. It has been replaced by a constant whine of excuses, complaints,
and special pleading. The collapse of the British character has been
as swift and complete as the collapse of British power.

Theodore Dalrymple,