Re: [CAD_CAM_EDM_DRO] Re: spinning ball nuts

In a message dated 2/7/2004 10:24:57 PM Central Standard Time,
plastiguy@... writes:
I'm curious why you think still a 1.25"
screw will be needed.
I must concede, I just don't really know for sure. I'd expect considerable
sag from 1" O.D. screw that long, and who-knows WHAT kind of "taut wire
vibration". Maybe a 1" screw would work, but you may-well have to "shop" to find the
pitch you want with the smaller dia. screws. Lotsa luck! Keep us informed
on this point! I'm sure this would be new experience we can use!

The ball-nuts on the 1.5" screws I used in the big job I mentioned were quite
bulky, and would fit into a cylinder no smaller than 3 or 3.5" dia, I think,
not counting the "mounting flange" which was surely 4". (It's been nearly 20
years, now, and I'd have to find the drawings and look, and, well, I can't
even recall instantly where I have filed all that!) My point: Rotating those
double (preloaded) nuts would be quite an act! I rotated the long screws up to
150 RPM, and the resulting linear rate for a 1" linear-move per turn
(double-start 1/2" pitch) was about right. Thus, rotating ball-nuts that fast might
require some balancing, etc. Problems with which I have no experience, so, as
Jose Hermanez said, "I don't want to THINK about it!"

Jan Rowland


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