OPERATION
STROKES PER MINUTE (SPM)
Stroke speed setting is a matter of personal preference and
experience. Generally speaking, lower speed settings are
preferred for some stippling, matting or staking functions. Try mid-
range settings for tasks requiring maximum power. Higher speeds
work best for fine, delicate cuts and to obtain the best finish.
The
GraverSmith
shows a range of 400 to 8,000 strokes per
minute. The calibrations on the dial are only approximate. Each
model of handpiece has a normal range of strokes per minute.
Operating outside this range can produce erratic operation at times.
HOW TO TUNE THE GRAVERSMITH
By “tuning” your machine, we mean adjusting the strokes per
minute and air pressure for optimum performance. TUNING
YOUR MACHINE PROPERLY IS THE SINGLE MOST
IMPORTANT OPERATION YOU SHOULD LEARN.
1. Turn ON your air
compressor and allow
the tank to fill. Wait for
the compressor to cycle
off and stop running.
2. Turn the GraverSmith
on and set the stroke
per minute dial
at 2300 and using the
regulator knob on the
front of the machine,
back the air pressure
down to 2 to 5 PSI (0.1
to 0.4 bar).
3. Hold the handpiece you
have selected to use
with the tool holder end
up (vertically) next to your ear FIG. 4).
4. WITHOUT depressing the foot control, SLOWLY increase
the air pressure until the handpiece begins to buzz. While
continuing to increase the air pressure, the handpiece will
vibrate, more air pressure will make it knock. Slowly add air
pressure and when the knocking barely stops and add 2 psi
(.13 bar), this is considered the perfect air pressure operating
range for any of the handpieces listed in the chart at the
bottom of the page.
Another method of tuning (although not as precise) is to use
the initial setting shown in the chart below. Set the Strokes
Per Minute dial to the Recommended Initial Setting. Set the air
regulator knob to the middle of the Normal Air Pressure Range
for the handpiece you are using. The goal is to use the least air
pressure possible that will properly operate the handpiece.
Remember, if the handpiece vibrates without depressing the foot
control, the air pressure is probably too low. If the handpiece
fades out at full throttle, the air pressure is probably too low,
or the strokes per minute is too high for that handpiece. The
handpiece should start to operate within 3/8" (9,525mm) of
depression of the foot control, if it doesn’t the air pressure is
probably too high. Always make small adjustments in air pressure
or strokes per minute, not large ones, until you are familiar with
your machine.
If you have “tuned” your machine properly, the handpiece will
operate smoothly and predictably. New operators often use too
much air pressure or the incorrect strokes per minute range.
This can make your machine difficult to control for fine work.
The
GraverSmith
has excellent control for the smallest stone
setting and the finest engraving. But, you must learn to “tune” the
machine correctly to achieve this fine control! After a while, you
can experiment with variations in air pressure and stroke speed
to suit your work preference.
HANDPIECE Tuning Chart
004-506 Large
800 - 2400
20 - 30 psi (1.4 - 2.1 bar)
1400
24 psi (1.6 bar)
004-508 Standard
1000 - 2800
18 - 23 psi (1.2 - 1.6 bar)
2000
20 psi (1.4 bar)
004-563 Bulino
1600 - 4000
19 - 23 psi (1.3 - 1.6 bar)
3000
20 psi (1.4 bar)
004-610 / 609 Hammer
1000 - 2700
20 - 25 psi (1.4 - 1.7 bar)
1800
22 psi (1.5 bar)
004-710 Hammer
1000 - 2700
20 - 25 psi (1.4 - 1.7 bar)
1800
22 psi (1.5 bar)
004-801 / 810 1800 - 4000
21 - 25 psi (1.5 - 1.7 bar)
3000
22 psi (1.5 bar)
004-720 Heavy-Duty
800 - 2400
20 - 30 psi (1.4 - 2.1 bar)
1400
24 psi (1.6 bar)
Standard Spring
1400 - 3400
18 - 22 psi (1.2 - 1.5 bar)
2700
19 psi (1.3 bar)
004-901/9 10 -
Fine Spring
1600 - 3600
12 - 15 psi (0.8 - 1.0 bar)
3000
13 psi (0.9 bar)
Standard Spring
2300 - 4000
11 - 14 psi (0.7 - 0.9 bar)
3600
12 psi (0.8 bar)
Fine Spring
2300 - 4000
5 - 9 psi (.34 - .62 bar)
3600
7 psi (0.4 bar)
004-940 Magnum
800 - 3400
20 - 23 psi (1.3 - 1.5 bar)
2400
21 psi (1.4 bar)
Normal Air
Pressure Range
psi (bar)
Normal
Operating Range
Strokes Per Minute
Recommended Initial Setting
Air Pressure
psi (bar)
Handpiece Type
Strokes
Per Minute
004-921
Monarch
004-901 / 910
FIG. 4
