Owner's manual

DIRECT ACTING CAM
INVERSE ACTING CAM
Figure 2-12. Characterized Cam Example
(II) Cut out paper cam leaving new cam
contour, mounting hole, and slotted
hole.
(v) Lie up mounting and slotted holes of
paper cam to mounting and slotted
holes of metal cam. Cement paper cam
to metal cam. Remove material from
cam as needed to give metal cam shape
of paper cam. Using a file or similar
tool, smooth carve until no ridges or
imperfections are felt on edge of c.arve.
(w) Install cam on power positioner and
check for a linear relationship between
actual flow of system and input signal
to power positioner. A 10% input
signal will produce a 10% flow, a 50%
input signal will produce a 50% flow.
Make minor adjustments by draw filing
cam.
(x) Record power positioner characterized
action ia Table 4-2, schedule 7’. Use
the following procedure:
1 Set signal air to 0%.
2 Measure distance. from top of
packing washer to bottom of
cl&s head.
1 Increase signal air to 10%.
4 Measure distance from top of
packing nut to bottom of clevis
head. Subtract value in step 2.
Record thii value as piston
movement in inches for 10%
signal air in Table 4-2.
5 Repeat steps 3 and 2 for 20% to
90% in 10% increments.
6 Divide actual distance traveled at
each signal by total distance
traveled to determine percent of
full sh-eke. Enter percent traveled
at each signal in percent of full
stroke column.