Porter-Cable Model 543 Instruction Manual page 11

VARIABLE SPEED
This saw is equipped with an adjustable variable speed control and the speed
range is 500 to 3100 SPM. The speed is adjusted by turning the control knob
(C), Fig. 5. The speed control may be adjusted with or without the motor running.
Use higher speed settings for fast cutting when finish and accuracy are not
critical. Use slower speed settings when accuracy and finish are critical or for
delicate materials.
BLADE ORBIT
The blade orbit may be varied by turning knob (A), Fig. 6, to any of four
positions indicated by the numbers "0" through "3", with "0" producing no
orbit and "3" producing maximum orbit. The orbit may be adjusted with or
without the motor running. Move knob (A), Fig. 6, to the detent in the housing
corresponding to the number on the housing. The knob is shown in position
"0". The straight up and down position would be setting "3". Metal cutting
should be performed in orbit setting "0".
Use of higher orbit settings when performing intricate scroll cuts may cause
blade breakage. The lower orbit settings are recommended for scrolling. Orbit
position "0" will produce the most accurate cuts with less splintering and the
longest blade life.
CHIP BLOWER
This saw is equipped with a chip blower to keep the cutting area free of chips.
Use knob (B), Fig. 6, to turn the chip blower on and off. The knob is shown in
the off position. To turn the chip blower on, turn the knob counterclockwise
until it stops.
PLUNGE CUTTING
a wall avoid contact with all
exposed metal on the tool to
prevent electrical shock hazard
resulting from accidentally cutting
into a live wire. HOLD SAW AS
ILLUSTRATED IN FIG. 7.
When cutting into
A
Fig. 6
11
B
Fig. 7