"Dave Hinz" wrote in message
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On 20 Jan 2005 09:14:31 -0800, jim rozen wrote:
In article , Dave Hinz says...
Can you use the lathe to turn the stock, and use a die to cut your
threads,
A die won't give a precision lead to the part. Because this is
a leadscrew for the lathe, that's not the best way to make
the part.
Ah, I missed the part about it being a lead screw for a lathe.
Leadscrews not only have to have the correct thread geometry,
but they are effectively length standards in and of themselves.
A die-cut leadscrew would work, but it would impart all the
lead error into whatever parts were then fabricated when
using it on the lathe.
So...how does one cut a clean leadscrew when one doesn't have
a clean leadscrew to start from? Someone made the first one...
I would guess (note the word "guess") that the better way would be to turn a
couple of threads onto the end of the stock and then stick it into a
precision nut which is the work holder for a grinding machine and grind the
thread. The grinding wheel is always going to be a constant distance from
the nut so just apply constant pressure to continuously turn the stock and
work it into the nut and a screw of unlimited length could be done
accurately. Maybe I can make an attachment for my lathe!
Steve.
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