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• Place the tool cutting point on the work piece BEFORE
applying power with the throttle. Attempting to enter the cut
with the power ON and the handpiece stroking will quickly dull
or damage the tool point.
• Apply power with the throttle only AFTER positioning the tool
on the work. Use slight forward pressure to keep the tool point
moving forward into the cut. Both tool angle and downward
pressure control the depth of cut. Avoid using too much
downward pressure; it’s tiring and often indicates the need for
better tool sharpening or a more relaxed technique.
• Vary the power input with the throttle to control the speed and
depth of cut. Do not let the cutting action get ahead of your
ability to guide the tool. Stop the throttle action to reposition
the work. Leave the tool point in the cut.
• Overcome the tendency to let the handpiece continue to
stroke when not actually cutting (by failing to take your foot off
the throttle.) With practice, control of the throttle becomes an
automatic response.
• Use a stable vise or heavy engraver’s block on a sturdy
workbench or table to hold the work. If the work is not held
solidly, vibration will decrease effectiveness of the tool’s
power and will quickly dull or chip the point. A GRS engraving
block is a most effective work holding device.
• Don’t push hard! If your hand becomes tired or cramped, you
aren’t using the power of the machine to do the work - or you
may not have the tool properly sharpened or heeled.
• Keep the tool sharp and properly heeled. Sharpen frequently -
before you lose the point entirely. With practice you will begin
to feel when the point is beginning to dull. At this time, only
a slight amount of sharpening is necessary to bring it back
to the desired sharpness. Hardness of the material you are
cutting will greatly affect tool life.
• There should be no noticeable vibration of the tool point in the
cut. If the point is allowed to vibrate in the cut, the point will
dull quickly.
ROTARY HANDPIECE
The GRS 850 Rotary Handpiece delivers high horsepower, but
low torque. Feather touch or brushing techniques remove the
most material possible. With this method, you will have a superior
tool for fine, delicate, intricate, and exciting work. The 850 Rotary
Handpiece is a precision instrument that can be easily damaged
if misused or improperly maintained.
Your rotary handpiece is
engineered for quality and
manufactured for long life. To
use, attach the handpiece to
the auxiliary air output on the
back of your GraverMach AT.
The handpiece is designed to
operate at a maximum of 35 psi
(2.4 bar). Turn auxiliary air knob
a few turns counter-clockwise.
Stop the rotary handpiece by
turning the auxiliary knob until
the air is turned OFF. For frequent ON/OFF usage, we
recommend adding a GRS foot switch in the air line. This will
facilitate your work.
NOTE: Read the instructions that come with the rotary
handpiece carefully.
ROTARY HANDPIECE SAFETY
1. Use safety glasses or goggles. Also use a face or dust mask
if cutting operation is dusty or if working on glass. When
working on glass, wet the surface to help keep the dust down.
2. Keep work area clean and uncluttered.
3. All visitors should be kept at a safe distance.
4. Do not force tool. It will do a safer and better job at the rate it
was designed for.
5. Use the correct burs. Do not force bur to do the job of a
heavier duty tool.
6. Use clamps or vise to secure work.
7. Avoid accidental starting. Turn tool OFF immediately after
use.
8. Do not depress bur ejector while running -- possible damage
to tool may occur.
9. Do not operate tool without a bur.
10. Use 35 psi (2.4 bar) or less air pressure.
WORK HOLDING
The workpiece must be held as firmly as possible. If it is not,
much of the power and cutting capability of the tool is lost. Use
either an engraver’s ball vise or a vise which can be rotated with
your free hand to position the work as the cut progresses. GRS
offers a selection of vises to fit different tasks.
A. GRS Foot Switch (#004-863)
B. GRS Variable Pressure Foot Control (#004-771)
A
B
FOOT CONTROL OPTIONS •
Shown with 850 Rotary Handpiece
GRS WORK HOLDING SYSTEMS
A. GRS Positioning Vise (#003-541) for microscope work
B. GRS Standard Block (#003-530)
C. GRS Microblock (#003-683)
D. GRS Magnablock (#003-021)
E. GRS BenchMate, work holding system for jewelers
A
B
C
D
E
