"Brian Lawson" wrote in message
...
Hey Robin,

Machine specific in some cases, but do a Google on

EIA 267-C

I've seen 5 axis machines with spindles "noses" that swivel. The
"nose" is a 45 degree mitre joint, so that if it is swiveled or
twisted one certain way it forms a 180 degree line with the spindle
motor shaft, lets say that position is horizontal, and if swung 180
degrees it forms a 90 degree joint to be vertical. If from the 180
position it is swung only 90 degrees, it stays horizontal, but at a 90
degree horizontal to the "180". That make any sense?? It works as a
"universal" head, so that in one configuration it would be operating
as what you referred to as a horizontal mill, and in the second
configuration (2 seconds later), the same machine is operating as a
vertical. I just don't know if the "axis designation" changes at that
instant too. I don't think it does, but I will ask on Monday.



While its ultimately up to the machine builder, generally the axes are
designated from the "machine home" position....so if a machine with a
tilting head homes out at vertical, and the rotary centerline is parallel to
the x ways, the tilt axis would be designated as -A-

To add rotary axis, X=a Y=b Z=c

And for parallel axes, X=u Y=v Z=w

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SVL