On Nov 23, 12:09 pm, _
wrote:
On Fri, 23 Nov 2007 09:02:29 -0800 (PST), wrote:
On Nov 23, 10:33 am, wrote:
Can anyone point me to possible sources for this critter?

Thanks,
DOC

No idea where you can get such a gear. You could try to make one.

That's the hard and expensive way.

The smart way is to use a 63 tooth gear which is much cheaper to get,
I believe.

I worked out the arithmetic for use of such a gear some years ago and,
while the conversion is not exact, it is so close that the inaccuracy
would get lost in the accumulated tolerances of the lead screw and
gear train.

The inaccuracy is only 1 part in 127, but it is all in one direction. If
you are threading a long part it could be a problem.


The error is MUCH smaller than 1 in 127, provided the proper gear
train is set up. There is more to it than a straight substitution
plus 1 to 2 ratio.

As I said, if there is interest I will dig out my calcs.

Wolfgang