GRS Magnum User manual

PAGE 1 of 4 LIT-258
ADJUSTING THE HANDPIECE
To position the hose, loosen the locking ring a little. With the locking ring
slightly loose, the handpiece body and knob can be turned independently.
Position the Quick Change holder with the graver “point” down. Rotate the
knob until the hose position is comfortable, then tighten the locking ring.
The length of the handpiece can be extended a little by unscrewing the
knob and body even more. NOTE: When the handpiece length is extended,
a loss of power may occur, depending on the type of work being done.
ATTACHING A NEW HOSE
Loosen the locking ring (Fig. 1). Remove the knob from the handpiece. Remove
the hose by cutting it off close to the knob. With a small punch, push the hose /
brass tting back into the knob body. Remove the brass tting (#044-031) from
the hose. Feed the new air hose through the hole in the knob (Fig. 2). Insert
the brass tting into the end of the new hose, making sure it is fully seated.
If needed, lubricate the tting rst to help it slip into the hose easier. Then apply
a small amount of water or oil around the outside end of the hose next to the
brass tting and pull the hose back (Fig. 3) into the knob until you see the tip
of the brass tting protrude through the side of the knob. This must be an air
tight t, so a bit of force may be needed (a few pounds of pressure, at least).
MAINTENANCE
Keep the Magnum handpiece clean on the inside. Problems will occur if oil
or moisture gets into the handpiece, especially on the piston. If you notice
a loss of power or erratic performance, rst check if the receiver (chuck) is
tight in the handpiece body. Using a crescent wrench or pliers with a graver
inserted in the QC Holder, gently tighten receiver clockwise (Fig. 4) If erratic
performance continues, then disassemble and clean the handpiece. To
disassemble the handpiece, use the crescent wrench or pliers to grip the
graver (Fig. 4) and turn it counterclockwise to loosen the chuck retainer.
After loosening, turn the chuck retainer out with your nger tips (Fig. 5).
As the chuck is pulled out, there will be a spring and piston that follows.
Loosen the locking ring and remove it (Fig. 6). Grip the knob and turn the
handpiece body counterclockwise until it is out of the knob body (Fig. 7).
Now, with the handpiece disassembled, clean the parts with a non-residue
solvent like denatured alcohol. Make sure the holes in the handpiece body
are clear from dirt and debris. DO NOT get moisture down the air hose.
If this happens you will need to clear and dry it before reassembly.
Before reassembly, make sure every thing is completely dry.
DO NOT OIL INSIDE THE HANDPIECE. NO lubricant is
required. Lubricant will actually decrease performance!
Magnum®& Magnum®Airtact Handpiece
INSTRUCTIONS • #004-940, #004-940-OVAL , #004-941, #004-940-ATSS & #004-957SS
Standard Spring
Normal Operating Range 18-22 psi (1.2-1.5 bar) /
1400 - 3400 spm
Recommended Initial Setting 19 psi (1.3 bar) / 2700 spm
PSI: Pounds per Square Inch • Bar: Unit of Measurement • SPM: Strokes Per Minute
LOCKING RING
Loosen first
Lubricate end
slightly with
water or a small
amount of oil.
TIGHTEN
TURN CLOCKWISE
LOCKING RING
FIG. 2
FIG. 3
FIG. 4
FIG. 5
FIG. 6
FIG. 7

LIT-258 PAGE 2 of 4
Very Light
synthetic grease film
FIG. 8
Hollow end
Very Light
synthetic grease film
044-026
002-127
2X
022-948
3X
044-029
022-072
044-028
044-030
044-031
002-605
044-025
044-023
004-803
6X
004-989
044-507
REASSEMBLY NOTE
There is an O-ring inside the knob that makes getting the handpiece
body to thread a little difcult when reassembling. Use a very small
amount of synthetic lube or non-stick grease and create a thin lm
around the OUTSIDE of the handpiece body between the threads
and the end (Fig. 8). See “Adjusting The Handpiece” on p. 1 of
this literature sheet for adjusting graver and hose position.
QUICK CHANGE HOLDER HINT
Synthetic Lube or non-stick grease on the shaft of a quick
change holder will make them easier to slip in and out.
NOTE: Do NOT use
petroleum based oils -
USE ONLY Synthetic
oils. Fossil oils can
damage the O-Rings.
Optional upgrades:
#044-507
Tungsten Piston
#044-163
Shortened Barrel
PART # DESCRIPTION QTY.
004-989 RECEIVER ASSEMBLY 1
044-025 HANDPIECE BARREL (MAGNUM) 1
044-026 LOCK NUT (MAGNUM) 1
002-127 O-RING, .754"OD .614"ID 2
044-030 PALM KNOB (MAGNUM) 1
044-031 HOSE RETAINER 1
044-028 TUBING, 050-003, 40"L 1
022-072 PLASTIC 1/4 TUBE CONNECTOR 1
044-029 TUBING, 050-002, 4"L 1
022-948 O-RING, 1.078"OD .938"ID 3
004-803 QC HOLDER 6
002-605 WRENCH, 5/64 ALLEN 1
044-023 SPRING COMPRESSION 1
044-507 HEAVY PISTON, MAGNUM 1
Magnum®Handpiece
PARTS LIST • #004-940

PAGE 3 of 4 LIT-258
Oval Magnum®Handpiece
PARTS LIST • #004-940-OVAL
002-127
044-026
004-989
044-025
044-023
044-507
022-948
002-127
004-281
044-027
002-605
044-028
022-072
044-029
004-803
6X
3X
Magnum®Airtact Handpiece
PARTS LISTS • #004-940-ATSS
044-028
022-072
044-029
023-029
023-024
8X
004-803
6X
044-130
002-605
044-162SS
044-031
044-126
044-219
044-025
002-127
2X
044-026
044-507
044-023
044-303
2X
044-231
004-944
024-201
004-989
PART # DESCRIPTION QTY.
002-127 O-RING, .754"OD .614"ID 2
002-605 WRENCH, 5/64 ALLEN 1
004-803 QC HOLDER 6
022-072 PLASTIC 1/4 TUBE CONNECTOR 1
023-024 PHILLIPS RD HEAD MACHINE SCREW 8
023-029 FITTING, M-.063"IDTUBE F-LUER 1
044-023 SPRING COMPRESSION 1
044-025 HANDPIECE BARREL (MAGNUM) 1
044-026 LOCK NUT (MAGNUM) 1
044-028 TUBING, 050-003, 40"L 1
044-029 TUBING, 050-002, 4"L 1
044-031 HOSE RETAINER 1
044-126 FITTING, .094"OD.063"ID X .35" 1
044-130 TUBING, 050-054, 43.6"L 1
044-162SS PALM KNOB (MAGNUM) 1
044-219 INLET INSERT FOR MAGNUM AT KNOBS 1
044-231 BRAIDED SLEEVE, 050-066, 36"L 1
044-507 HEAVY PISTON, MAGNUM 1
044-303 HEAT SHRINK WRAP, 050-091, 1"L 2
004-944 ACTUATOR PALM CAP AND COVER KIT
FOR AT HANDPIECES 1
024-201 PH1 x 50 MM screw driver 1
004-989 RECEIVER ASSEMBLY 1
PART # DESCRIPTION QTY.
044-025 HANDPIECE BARREL (MAGNUM) 1
044-026 LOCK NUT (MAGNUM) 1
002-127 O-RING, .754"OD .614"ID 2
004-803 QC HOLDER 6
002-605 WRENCH, 5/64 ALLEN 1
044-027 OVAL KNOB (MAGNUM) 1
004-281 HOSE RETAINER 1
022-948 O-RING, 1.078"OD .938"ID 3
044-028 TUBING, 050-003, 40"L 1
022-072 PLASTIC 1/4 TUBE CONNECTOR 1
044-029 TUBING, 050-002, 4"L 1
044-023 SPRING COMPRESSION 1
044-507 HEAVY PISTON, MAGNUM 1
004-989 RECEIVER ASSEMBLY 1

LIT-258 PAGE 4 of 4
900 Overlander Road • Emporia, KS 66801 USA
800-835-3519 • 620-343-1084 • Fax: [phone]
[email protected] • www.grs.com
Last Updated: 12/10/21
Please Note: the Palm Pad mounting screws should only be
lightly snug; over-tightening can distort or damage the pad.
Magnum®Airtact Palm Knob Kit
PARTS LIST • #004-957-SS
004-944
044-028
022-072
044-029
044-231
023-029
044-130
044-031 044-126
044-219
044-162SS
002-127
044-026
023-024
044-204 024-201
PART # DESCRIPTION QTY.
002-127 O-RING, 0.750" O.D. 0.610" I.D. 1
022-072 TUBE COUPLING, 0.170" I.D. 1
023-024 SHCS, #2-56 x 0.19" S/S 8
024-201 SCREWDRIVER, PH #1 X 50 MM LG 1
023-029 FITTING, M-0.063" I.D.TUBE F-LUER 1
044-028 TUBING, PU CLR 0.250" O.D. 0.160" I.D. 1
044-029 TUBING, PU CLR 0.250" O.D. 0.170" I.D. 1
044-031 HOSE RETAINER 1
044-126 FITTING, 0.094" O.D. 0.063" I.D. x 0.35" 1
044-130 TUBING, PU CLR 0.125" O.D. 0.063" I.D. 1
044-162SS PALM KNOB (MAGNUM) 1
044-303 12 MM DIA BLACK SHRINK TUBING 2
044-219 INLET INSERT FOR MAGNUM AT KNOBS 1
044-231 BRAIDED SLEEVE, 0.375" O.D. NYLON 1
004-944 HANDPIECE ACTUATOR ASSEMBLY 1
TYPE-E PALM PADS
The latest palm pad design for Airtact®hand control is
Type-E, available in four sensitivity levels: 4, 6, 8, and 10.
The handpiece is more responsive (less force required
to activate) with a lower number palm pad installed.
Initially, palm pads can be stiff. This affects the feel and
control. Stiffness may be reduced naturally with a few
hours of use. To reduce stiffness quickly, bend and twist
the control flap to soften. When the preferred softness
is nearly reached, stop and test frequently to adjust
until desired responsiveness is attained. The rubber
control flap can be formed for a custom feel as well.
FORMING THE RUBBER CONTROL FLAP
The flexible rubber control flap on the Palm Pad
transforms hand force into handpiece power by
progressively covering a small air vent hole in the
upper rear of the Airtact®handpiece knob.
Forming or bending the control flap one way (concave)
increases the required hand force; bending it the
other way (convex) decreases hand force.
Control Flap
Palm Pad #8
Moderate to heavy
hand force
Palm Pad #10
Most hand force
Palm Pad #4
Least hand force
Palm Pad #6
Light to moderate
hand force
Concave
Convex
To increase required hand force:
Bend the control flap into a more
concave shape. Bending the flap
this direction keeps the flap from
sealing off the Airtact®knob hole
until more hand force is applied.
To decrease required hand force:
Bend the flap into a more
convex shape to decrease
the hand force required. This
shape seals the Airtact®Knob
hole with less force applied.
Palm Pad
FINE ADJUSTMENT • #004-940-ATSS & #004957SS