Operator`s manual

Advanced Haas Mill Programming Techniques Training Manual Page 71
Extra Axis Coordinate System
The illustration below at first glance gives confusing information. By convention an A axis rotates around
the X-axis. Using the right hand rule when the thumb is pointed in the positive X direction a positive
rotation will be in the direction of the fingers are pointed. This is indicated in the illustration below right.
Another way to look at it is, if you are facing the rotary head, a positive rotation is clockwise. Note bottom
left figure gives the direction of the positive direction of A axis work coordinates. They go counter
clockwise. That is 90⁰ is at 9 o’clock position, 180⁰ is at 6 o’clock position, 270⁰ is at 3 o’clock position. It is
similar to where a positive movement of the table in the X or Y axis is opposite the positive direction of the
work coordinates.
For the B axis to be lined up with the Y axis below the A axis would have to be rotated to the +90 degree
position on the trunion table below. Then the right hand rule would apply as above. This will only apply if
the rotary unit is positioned to the right.
The following illustrations would be from the left side view point of a Haas HRT160 Rotary Table with a
Tooling Block System attached below.
The above illustrations are taken from Haas Rotary/Tailstock Operators Manual, December 2012.