Download - Haas Automation, Inc.

3. Make sure the mill has the same number of M functions programmed as
steps in the rotary control.
4. Do not program two M functions, one directly after another, in the mill to
index the rotary control. This may cause a timing fault in the mill. Use a dwell of
1/4 second between them.
Simultaneous Rotation and Milling
G94 is used to perform simultaneous milling. The relay is pulsed at the beginning
of the step so that the NC mill will go to the next block. The rotary control
then executes the L steps without waiting for start commands. Normally the
L count on the G94 is set to 1 and that step is followed by a step which is run
simultaneous with an NC mill.
Spiral Milling (HRT & HA5C)
Spiral milling is coordinated movement of the rotary unit and the mill axis. Simultaneous
rotation and milling allows machining of cams, spiral, and angular cuts.
Use a G94 in the control and add rotation and feed rate. The control executes G94
(signals mill to proceed) and the following step(s) as one. If more than one step is
required, use an L command. In order to spiral mill, mill feedrate must be calculated
so rotary unit and mills axis stop at the same time.
In order to calculate the mill feed rate, the following information needs to be addressed:
1. The angular rotation of the spindle (this is described in the part drawing).
2. A feed rate for the spindle (arbitrarily select a reasonable one, for example,
five degrees (5 o ) per second).
3. The distance you wish to travel on X-axis (see part drawing).
For example, to mill a spiral that is 72 o of rotation and move 1.500” on the X-axis at
the same time:
1. Compute the amount of time it will take the rotary unit to rotate through the
angle
# of degrees / (feed rate of spindle) = time to index
72 degrees / 5° per sec = 14.40 seconds for unit to rotate.
2. Compute the mill feed rate that will move the X distance in 14.40 seconds
(length to travel in inches/# of seconds of rotation) x 60 seconds = mill feed
rate in inches per minute.
1.500 inches/14.4 seconds = 0.1042 inches per second x 60 = 6.25
inches per minute.
Therefore, if the indexer is set to move 72 o at a feed rate of 5 o per second you will
have to program the mill to travel 1.500 inches with a feed rate of 6.25 inches per
minute for the spiral to be generated. The program for the Haas control would be
as follows:
96-0315 Rev P
April 2012
37
Original Instructions