AIRBRASIVE H II Series User manual
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Overview
AIRBRASIVE® MICRO ABRASIVE BLASTING TECHNOLOGY
Airbrasive® Jet Machining is a process in which high pressure air and very fine powder are blended in a chamber to form
an abrasive mixture. This mixture is then sent through a small, precisely machined nozzle. The result is a highly accurate
abrasive stream that can be used for cleaning, cutting, drilling, deburring, and finishing all types of surfaces. Airbrasive®
Machines have limitless applications. These highly engineered machines are incredibly versatile. They have the power to
cut and drill materials as hard as diamonds, as well as the precision to delicately clean debris from ancient papyrus
documents.
OPERATING PRINCIPLES
The Airbrasive® Machine is capable of many cutting and abrading tasks. From cutting very hard materials such as diamonds
to cleaning extremely delicate items like fabric or paper. The key to taking advantage of its versatility is the knowledge of
how it cuts. Knowing this, you can properly set the various controls to achieve your desired cutting results. There are six
key variables involved in the cutting process. 1) Air Pressure, 2) Powder Flow Rate, 3) Nozzle Size, 4) Type of Powder, 5)
Nozzle Distance from work piece, and 6) Angle of Impingement.
AIR PRESSURE
The air pressure is directly related to the velocity of the powder particles striking your work piece. The higher the air
pressure the faster the particles and the greater the cutting speed. The lower the pressure the, lower the cutting speed.
This is not a linear correlation. There are certain critical points you will notice as you experiment with different air pressure
settings. When the particle velocity falls below a certain level the cutting action may suddenly stop altogether. Similarly, a
small increase in air pressure may gain a large increase in cutting action. The air pressure is limited at the high end by safety
concerns and by what your main air supply can produce.
The unit should never be pressurized beyond 140 PSI!
POWDER FLOW RATE
The amount of powder exiting the nozzle per minute is referred to as the flow rate. The greater the flow rate, the greater
the cutting action. To achieve the better cutting action with higher powder flow rates, it is often necessary to increase the
air pressure. This is done to maintain particle velocity which tends to slow down as the mass the air stream must carry
increases. Cutting action will decrease quickly at very high powder flow rates. This is due to interference between the
powder particles bouncing off the work piece and those coming out of the nozzle. Some brief experimentation at these
high flow rates will quickly reveal your limits.
NOZZLE SIZE
Nozzle orifices are shaped to be either round or rectangular. The nozzle widths vary in size from .005 up to .032 inches.
The size of the nozzle determines the area that will be impacted by the powder. The larger the nozzle, the greater the area.
The shape of the nozzle is important for getting into unusually shaped spaces. A rectangular nozzle can lightly cover a large
width or, when turned, heavily impact a narrow space.
TYPE OF POWDER
The cutting powder is the most important variable in the "Airbrasive" process. It determines the severity with which you
will impact your part. Some powders are designed for aggressive removal of material while others for a gentle cleaning. To
achieve consistent, sputter free smooth flow it is necessary to use uniformly sized powder. If the powder particles vary in
size, even a little, the powder will tend to clump together. This happens because the smaller particles fill in the gaps
between the larger particles, effectively locking them all together. If all the particles are of the same size, then this locking
action cannot take place.
NOZZLE DISTANCE TO WORKPIECE
The distance you hold the nozzle from the work piece plays a large part in determining the area covered as well as the
cutting rate.
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ANGLE OF IMPINGEMENT
The angle at which you hold the nozzle regulates the speed and efficiency by which material can be removed from the
work piece. There are two theories at play here, one based on material removal by brittle failure and the other on material
removal by ductile failure. Brittle failure occurs when impacting powder granules penetrate the work surface and literally
blast particles out of it. Ductile failure occurs when the powder granule strikes the work surface at an angle of less than 90
degrees and removes material by generating a chip.
Tests have shown that maximum material removal for ductile materials occurs between a 15- and 45-degree angle of
incidence. For a brittle material, maximum removal occurs at an angle of 90 degrees.
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Section 1: Introduction and Description
INTRODUCTION
A. Scope. This technical manual contains operation and service instructions, as well as an illustrated parts list for the
Airbrasive® Model H Series II manufactured by Airbrasive Jet Technologies, LLC.
B. Characteristics. The Airbrasive® Model H Series II is an electrically powered device that incorporates a patented electro-
magnetic vibratory feed system for powder delivery. The Model H series II unit has been designed to accommodate both
the intermittent and continuous production demands of high-volume producers.
SPECIFICATIONS
1. Air Supply Requirements
110 ± 30 PSI (0.5 CFM @ 80 PSI min., 140 PSI max.)
Dry, clean, compressed air, carbon dioxide, or nitrogen.
2. Electrical Power Requirements
AU213: 220V, 50HZ, Single Phase, Three Wire The plug supplied is three-
prong, polarized, providing an earth ground.
3. Weight
60 lbs. (27.27 kg)
4. Dimensions
22-1/2” x 14-7/8” x 9-5/8” (H x W x D)
57.2 cm x 37.8 cm x 24.4 cm (H x W x D)
WARNING: The use of oxygen as a gas supply presents the possibility of an explosion occurring. Under no
circumstances should oxygen be used.
IMPORTANT: A suitable dust collector system is required to maintain operator's exposures to powder dusts below
permissible exposure limits such as those regulated by OSHA or recommended annually by ACGIH (American Conference
of Governmental Industrial Hygienist). Consult the manufacturer of the dust collector equipment for the correct filter for
other dusts or air contaminants resulting from material being abraded.
AIR SUPPLY NOTE
Many compressed air lines are contaminated with moisture, oil, and dirt, which are detrimental to the performance and
operation of the Unit. Moisture filters and unloaders must be used. These items can be purchased directly from Airbrasive
Jet Technologies, LLC.
POWDER NOTE
The MODEL H UNIT is designed to use specially prepared powders that are meticulously screened for uniform particle
size. These specialty powders insure smooth flow through the many precision ports and feedthroughs. The use of any
other type of powder can result in clogging of the internal components and potential damage to the unit. For more
information on these powders, contact Airbrasive Jet Technologies, LLC at (866) 272-0540.
AIRBRASIVE® MODEL H II: STANDARD EQUIPMENT
Description
Part Number
Quantity
Airbrasive® Model H
AU213
1
Nozzle (Rt. Angle .018” I.D)
AN118
1
Nozzle (Straight, Round, .018” I.D.)
AN119
1
Nozzle (Straight, Rectangular, .006” x.060”)
AN124
1
AccuBrade 27 –Aluminum Oxide
AP101
4 lbs.
AccuBrade 50 –Aluminum Oxide
AP105
4 lbs.
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Section 1a: Description of Components (Sorted Alphabetically by Part #)
AC107 | AUXILIARY CHAMBER
The purpose of the auxiliary chamber is to store powder and keep the mixing chamber level constant. This allows the
mixing chamber to feed a constant amount of powder into the air stream.
AC118X2 | MIXING CHAMBER ASSEMBLY
When the mixing chamber is vibrated, powder falls through small holes in the orifice plate assembly and is entrained into
the air stream flowing through the chamber base. This is where the air and powder are precisely blended into the mixture
you need for your application.
AE104 | FUSE HOLDER SOCKET
AE130X | POWDER REGULATION ADJUSTMENT
This knob adjusts the voltage being applied to the vibrator/mixing chamber assembly. It regulates the powder flow rate
exiting the nozzle
AE133X | AIR SUPPLY SOLENOID VALVE
With the SYSTEM POWER SWITCH set to "On", this solenoid valve is energized providing the unit with air. When the
SYSTEM POWER SWITCH is set to "Off", the valve closes, blocking air to the unit. The valve is not field repairable. Replace
if it malfunctions.
AE182 | POWER OUTLET
Your external power source is connected here.
AE188 | RELAY
The relay provides a switch function for the operation time and pinch valve actuation indicators.
AE189 | SYSTEM POWER ON/OFF SWITCH
The master switch for electrical current supplied to the unit. This will initiate bleeding of all pneumatic lines when switched
off during use. Allow a minimum of 20 seconds after turning system power off before attempting to open powder chamber;
it takes this long for all pneumatic lines to bleed off and reduce pressure in the chamber to safe levels.
AE190 | CONTINUOUS OR FOOT SWITCH TOGGLE
Set this to CONTINUOUS if you want a steady, uninterrupted stream of powder flow. Set to FOOT SWITCH ACTIVATED
if you want to use the foot switch to control the stream of powder flow
AE191 | OPERATION TIME INDICATOR
A clock which represents the cumulative hours the unit has operated from the time of its purchase. Clock only runs when
SYSTEM POWER ON/OFF switch is in the on position.
AE192 | PINCH VALVE ACTUATOR
A cumulative reading of the number of times the pinch valve has been pinched shut. Use these readings to determine
maintenance schedules for the replacement of the pinch tube.
AE193 | PINCH VALVE SOLENOID
Controls the air pressure to the pinch valve assembly. When the SYSTEM POWER SWITCH is "On", the solenoid allows air
pressure to enter the pinch valve assembly. Air enters the bottom of the solenoid, flows through passages and ports to
displace the piston which causes the depressor to pinch the tube closed.
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AE193 | BLEED SOLENOID VALVE
Controls air pressure to bleed valve assembly. When the SYSTEM POWER SWITCH is set to "On", the solenoid allows air
to enter the assembly. This closes the pinch tube within the assembly. When the SYSTEM POWER SWITCH is set to "Off",
the solenoid blocks the air from entering the assembly, thus opening the pinch tube.
AE202 | ELECTRICAL INTERLOCK
Disengages electrical power when the front panel is opened while the unit is plugged into an electrical outlet. When the
front panel is opened a limit switch opens the main electrical circuit, disabling the unit (the unit cannot be pressurized with
the cover open).
WARNING: Some components are still connected to your external power source. The main power cord should
always be disconnected before servicing the unit.
AE204 | FOOT SWITCH RECEPTACLE
Attach the foot pedal to this outlet.
AE236 | POWDER LEVEL SENSOR
The powder refill sensing circuit provides automatic indication of low powder level in the mixing chamber. When powder
level is low, the sensor sends a signal to the pilot light on the front panel to warn the user to fill the auxiliary chamber with
powder.
AG103 | PINCH VALVE PRESSURE GAUGE
This shows the pressure that the pinch valve assembly is set at. It is the pressure being applied to the "pinch tube" to cut
off powder flow when the unit is being used in the FOOT SWITCH ACTIVATED mode. The adjustment for this setting is
located inside the unit.
AG107 | POWDER REGULATION GAUGE
A relative measurement of how much powder is entering the flow stream. The gauge measures voltage being applied to
the vibrator/mixing chamber assembly. The higher the voltage, the greater the vibration and resultant powder flow.
AG111 | CHAMBER PRESSURE GAUGE
A measure of the air pressure in the mixing chamber, auxiliary chamber. This is the air pressure that will be seen at the
nozzle. Do not attempt to open auxiliary chamber to refill powder until this gauge reads "0 PSI". This gauge is not repairable
and should be replaced with a new one if it malfunctions
AH110X | HAND PIECE HOSE
The hose leaving the pinch tube assembly, passing through the front panel and connecting to the handpiece. The regulated
air/powder mixture runs through this hose to the nozzle.
AQ104 | AIR OUT FITTING
A hose is provided from the back panel to bleed pressure from the system when refilling powder or performing
maintenance. This hose should be routed to an appropriate dust collection system.
AQ205 | AIR IN
External air source is connected here.
AR133 | INTERLOCK CYLINDER
When the unit is pressurized, the interlock cylinder rod extends outward, locking the top cover to prevent opening. When
the air supply solenoid valve blocks air flow, and the unit is bled, the cylinder rod retracts allowing the cover to be opened.
WARNING: This prevents opening the auxiliary chamber when pressurized –which is dangerous.
WARNING: An Interlock is provided for increased operator safety and should not be disabled.
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AR139 | RELIEF VALVE
If primary system pressure is excessive the relief valve will pop open to reduce it. Once the pressure has been lowered
the relief valve will reset automatically.
AR140 | CHAMBER PRESSURE ADJUSTMENT
Regulates incoming air line pressure to the desired level in the mixing chamber. This regulates the powder cutting pressure.
This regulator is not field repairable. In the event of a malfunction, replace.
AR140V2 | PINCH VALVE ASSEMBLY REGULATOR
Controls the amount of air pressure going to the pinch valve assembly. It is normally preset at 40 PSI. This regulator is not
field repairable. In the event of a malfunction, replace.
WARNING: The Pinch Valve Regulator is factory adjusted and locked at 40 PSI. This setting should not be changed.
Less pressure will not operate the air pinch valve; more will result in abnormal wear.
AR142Z | PINCH VALVE ASSEMBLY
This assembly provides a path for the air/powder mixture to flow to the handpiece. When the SYSTEM POWER SWITCH
is "On', air enters the assembly to depress the pinch tube. This blocks the air/powder mixture to the handpiece. When the
foot pedal is depressed or you are in a continuous powder flow mode, the air is bled out of the assembly, thus opening the
tube to allow flow.
AR142Z1 | BLEED VALVE ASSEMBLY
This assembly allows a bleed path for the auxiliary chamber when the unit is shut down
AR182 | LOW POWDER INDICATOR
The Unit has a powder refill sensing circuit. It automatically indicates when the powder in the mixing chamber is low. The
probe is mounted between the auxiliary and mixing chamber. When powder is low, the sensor sends a signal to the low
powder indicator telling the end user to fill the auxiliary chamber with powder.
AR183 | AIR PRESSURE INDICATOR
This tells you if your incoming air line pressure is available.
AR186 | LEAK DETECTOR
This pneumatically operated sensor will display a green dot in its window if the pinch tube leaks
AV104X2 | VIBRATOR
The mixing chamber is oscillated by the vibrator assembly. The amplitude of vibration is controlled by the POWDER
REGULATION ADJUSTMENT knob. The greater the vibration amplitude the higher the powder flow rate.
VARIOUS | NOZZLE
Where the powder leaves the unit under pressure. Nozzles come in a variety of shapes and sizes depending on what
application you are dealing with.
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FRONT PANEL
9
INSIDE THE UNIT
15
Auxiliary Chamber
AC107
22
Vibrator Assembly
AV123X2
16
Interlock Cylinder
AR133
23
Relay
AE221
17
Mixing Chamber Assembly
AC118X2
24
Bleed Pinch Valve Assembly
AR142Z1
18
Powder Level Sensor
AE236
25
Bleed Valve Solenoid
AE193A
19
Electrical Interlock
AE202
26
Main Solenoid Valve
AE133AX
20
Pinch Valve Assembly
AR142Z
27
Pinch Valve Solenoid
AE193A
21
Pinch-Bleed Valve Assy. Regulator
AR140V2
28
Relief Valve
AR139
15
16
17
18
19
20
21
22
26
23
24
25
27
28
10
REAR VIEW
29
Air In Fitting
AQ205
32
Air Out Fitting
AQ104
30
Electric Outlet
AE182
33
Foot Switch Receptacle
AE204
31
Fuse Holder Socket
AE104
Foot Switch (not shown)
AE103X
29
30
31
33
32
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Section 2: Installation and Unit Checkout
INSTALLATION
A. Attach the BLOW OFF TUBING (plastic tubing shipped with the Unit) to the fitting (32) on the rear of the Unit.
Attach the other end of the BLOW OFF TUBING to an available exhaust system to evacuate excess powder from
the Unit.
B. Connect the end of the AIR IN fitting (29) to the external air supply (see page 2 for supply requirements).
C. Set the SYSTEM POWER ON/OFF Switch (1), on the front panel to "Off", and the POWDER REGULATION SETTING
Knob (2), completely counterclockwise.
D. Connect the provided power cord to the unit's power outlet (30) and plug the other end into an available outlet (see
page 2 for electrical requirements).
E. Set SYSTEM POWER ON/OFF switch to "On".
NOTE: If the SYSTEM POWER ON/OFF switch does not light, it indicates loss of electrical power. Check Unit fuse
(31) and if OK, check input power source.
F. Check reading on the CHAMBER PRESSURE GAUGE (5). Set the main air pressure to desired level by adjusting
the CHAMBER PRESSURE ADJUSTMENT regulator (6).
G. Plug the FOOT SWITCH PLUG in to FOOT SWITCH receptacle (33). Set the CONTINUOUS OR FOOT SWITCH
ACTIVATED switch (9) to FOOT SWITCH.
H. Press foot pedal. Air should flow from the hand piece nozzle.
CAUTION: Never direct the nozzle towards the face when operating the foot switch. Always use a suitable
dust collector system whenever using the unit.
I. Set SYSTEM POWER ON/OFF switch to "Off". This bleeds off any residual air remaining in the mixing chamber.
CAUTION: Keep SYSTEM POWER ON/OFF switch to "Off" for a minimum of 20 seconds each time the Unit
is turned off. This will allow enough time to bleed the mixing chamber.
J. Install nozzle (14) in hand piece (13).
K. Place SYSTEM POWER ON/OFF switch to "On" and set POWDER REGULATION ADJUSTMENT knob to obtain
the desired amount of powder flow for the operation to be performed (nominal setting for most operations is in
MED range of POWDER REGULATION GAUGE.
L. Set unit to CONTINUOUS OR FOOT SWITCH ACTIVATED as desired to obtain powder flow through the nozzle.
UNIT SHUTDOWN
Place SYSTEM POWER ON/OFF switch to" Off". Remove hose connection from air supply source.
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Section 3: Operation Instructions
This section includes a description of the operating procedures and controls. The operation instructions also describe the
capability and use of the UNIT.
TURN-ON PROCEDURE
NOTE: This procedure applies after the Unit has been installed and checked as described on Page 12.
A. Set SYSTEM POWER switch to "Off", and rotate POWDER REGULATION ADJUSTMENT knob completely
counterclockwise; also set CONTINUOUS POWDER FLOW/FOOT SWITCH to FOOT SWITCH.
B. Connect AIR IN fitting to an external air supply.
C. Check that power supply cord is plugged into an electrical outlet.
D. Set SYSTEM POWER switch to "On". Check that the switch is glowing red.
E. Check PSI reading on CHAMBER PRESSURE SETTING gauge. Adjust CHAMBER PRESSURE ADJUSTMENT knob
as required.
F. Check that no air flow is coming from the hand piece. This indicates the pinch valve tube is closed. If necessary,
adjust pinch valve regulator until there is no flow of air/powder from nozzle of hand piece. When adjusting the pinch
valve regulator (21), the front panel must be opened. This opens the ELECTRICAL INTERLOCK (19) which
disengages electrical power to the unit. To adjust pressure, the ELECTRICAL INTERLOCK must be held in place.
This will mimic the front panel being closed. You may now adjust the regulator (21) until there is no air/powder
flow from the regulator.
NOTE: Please adjust slowly. Less pressure will not operate the PINCH VALVE ASSEMBLY; more will result in
abnormal wear.
G. Set SYSTEM POWER switch to "Off".
CAUTION: Do not set pinch valve air pressure too high, it will result in excessive tube wear. Do not direct the hand
piece towards the face.
H. Select and install proper nozzle in hand piece for the operation to be performed.
I. Check powder in auxiliary chamber (15).
J. Set POWDER REGULATION ADJUSTMENT knob until POWDER REGULATION SETTING gauge is at desired
setting. For normal operation, the gauge should be in MED range.
K. Set SYSTEM POWER ON/OFF switch to "On". The UNIT is ready for operation.
L. For continuous powder flow, without actuating footswitch, set CONTINUOUS POWDER FLOW/FOOT SWITCH
ACTIVATED switch to CONTINUOUS.
TURN-OFF PROCEDURES
When turning the unit off for short periods of time, set the SYSTEM POWER ON/OFF switch to "Off" position. If the unit
is to be shut down for an extended period, proceed as follows:
A. Set SYSTEM POWER ON/OFF switch to "Off.
B. Unplug power supply cord.
C. Disconnect air supply hose from external source.
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Section 4: Service Instructions & Component Maintenance
PERIODIC INSPECTION
This unit should be inspected periodically for the following signs of wear.
A. Damaged case or top cover.
B. Frayed or worn hoses.
C. Frayed or broken wires.
D. Blown indicator lamp.
E. Worn nozzle.
F. Loose hose connections.
PERIODIC CLEANING
A. Clean out dust, dirt, and spilled powder from the Unit’s interior using low pressure compressed air. Remove
stubborn dirt with a brush. Do not use cleaning fluid on the hoses.
B. Clean the external surface with a soft lint-free cloth moistened with a suitable non-toxic cleaning solution.
NOZZLE TIPS
A 3/64" I.D. nozzle tip supplied with the unit (See page 5), and made of sintered tungsten carbide, must be handled with
care. Nozzle tips for special applications are available. Nozzle tips wear through the bore enlarging the side wall and piercing
through. A fuzzy air powder stream, with lack of definition, is a sign that the nozzle is worn and should be replaced. Replace
a nozzle by unscrewing the tip from its connector and replace with a new one. Screw the new nozzle securely to the hand
piece connector to avoid powder leaks.
CAUTION: Nozzle tips are manufactured of sintered tungsten carbide and may break if not carefully handled. They
should be stored in a safe place when not in use.
On occasion the nozzle will clog due to an excessive flow of powder. Unclog a nozzle as follows:
A. Remove the nozzle from its connector. Blow out obstruction using shop air hose, or
B. Turn the POWDER REGULATION ADJUSTMENT knob completely Counterclockwise (CCW).
C. Hold the tip end of the nozzle tight against the connector.
D. Turn the unit on and actuate the foot switch, supplying air to reverse flush the clogged tip. This should be
E. done in an exhaust chamber.
PINCH VALVE TROUBLESHOOTING
If the pinch valve fails to operate properly the problem could be caused by the solenoid or foot switch. Low voltage across
the solenoid coil will cause it to hum and not click. Check the voltage across the solenoid coil. If it is low, check the power
line voltage. If line voltage is correct check for a drop across the foot switch contacts. If there is a drop replace the foot
switch. If not, replace the solenoid. If the pinch valve tube stays open when the unit has air, troubleshoot as follows:
A. Remove the bottom hose connection from the pinch valve and check if there is air pressure. It should be 40 PSI.
If the pressure is incorrect adjust the pinch solenoid regulator (27). If no adjustment is possible replace the
regulator.
B. If pressure is available remove and disassemble the pinch valve assembly. Clean parts and replace any that are
worn or damaged. (See drawing: Page 20).
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The rubber pinch valve tube wears and will eventually leak. The valve does not have to be removed from the Unit for tube
replacement which is accomplished as follows: (See drawing: page 20)
A. Set SYSTEM POWER ON/OFF switch to "Off" position.
B. Disconnect hoses from air pinch valve tube.
C. Remove top block from assembly by removing two knurled screws. Remove worn pinch valve tube from bottom
block. Carefully insert the new pinch valve tube into the bottom block indentation. Align the pinch tube's seam to
the side of the block.
D. Carefully replace top block, again making certain that the tube aligns with the indentations in the top block. Secure
top block in place with attaching hardware.
E. Connect hoses removed in step (b) above.
F. Turn Unit on and check for proper operation with no air leaks.
POWDER REGULATION ADJUSTMENT KNOB
The powder flow rheostat adjusts the magnetic coil voltage level. If it malfunctions check electrical connections at the
rheostat. If this is not the problem, check operation as follows:
A. Connect a voltmeter across the input to the magnetic coil of the vibrator assembly.
B. Turn the POWDER REGULATION ADJUSTMENT knob completely counterclockwise.
C. With the SYSTEM POWER ON/OFF switch set to "On" and the foot switch actuated, observe the reading on the
POWDER REGULATION SETTING gauge while slowly turning the POWDER REGULATION ADJUSTMENT knob
CW. The range of the gauge reading from completely CCW to fully CW should be from low to high.
D. If the gauge reading in step (c) above does not indicate any change over a wide range of knob movement and then
suddenly jumps to maximum reading, it indicates faulty wiper arm contact or an open winding in the rheostat.
Replace rheostat; the item is not field repairable.
VIBRATOR
Each vibrator assembly (22) is factory adjusted to produce the desired vibrating characteristic.
CAUTION: The POWDER REGULATION ADJUSTMENT knob should never be set too high. This will cause audible
striking of the pole pieces by the magnetic coil armature. It will create an excessive amount of vibration that could
cause damage to the Unit.
If the Vibrator does not function properly while under warranty, it must be removed and returned to Airbrasive Jet
Technologies, LLC, for readjustment and/or repair. To remove the assembly, disconnect all electrical wires and pneumatic
hoses (and tag) from the vibrator (22) and mixing chamber (17). The vibrator and mixing chamber assemblies can now be
lifted directly from the multi-plane mounting shock absorbers. Detach the mixing chamber from the vibrator by removing
the attaching hardware. To reassemble and install reverse the above procedure. After installation, check the Unit for proper
operation with no leaks.
AUXILIARY CHAMBER AND MIXING CHAMBER
The auxiliary chamber (15) and mixing chamber (17) function together. The purpose of the auxiliary chamber (which is
mounted above the mixing chamber) is to store powder and keep the mixing chamber level constant. This allows the mixing
chamber to feed a constant amount of powder into the air stream. The auxiliary chamber doesn't vibrate, mixing chamber
vibratory motion is absorbed by the hose assembly (which joins the two chambers together) resiliency. Powder flow rate
is determined by air pressure level (set by CHAMBER PRESSURE ADJUSTMENT knob) and vibration amplitude (controlled
by the POWDER REGULATION ADJUSTMENT knob) imparted on the mixing chamber by the vibrator assembly.
AUXILIARY CHAMBER AND MIXING CHAMBER MAINTENANCE
15
The auxiliary chamber (15) does not normally require maintenance unless a new O-ring is needed. When removing the O-
ring make certain the old one is completely removed from its groove, and no parts of it fall into the chamber. If they do,
remove them. (See detailed drawing: pages 21 & 22).
CAUTION: The O-ring must be seated in its groove when top cover is secured. If the ring is not properly installed,
air leaks will occur.
It is normally not necessary to remove the mixing chamber (17) unless the powder cakes (due to excessive moisture in the
compressed air) or the orifice plate needs replacement. If it is necessary, proceed as follows:
A. Mark the position of the mixing chamber on the vibrator (22). This is necessary, so when reassembling, it is not
put in another location causing the vibrator to change its vibratory characteristics. This will also prevent stretching
and kinking of air and powder hoses. (See pages 21 & 22)
B. Remove the one screw that retains the mixing chamber to vibrator via the small cleat. Loosen the other two screws
from the larger double cleat.
C. Loosen the three screws which retain the base cap of the mixing chamber.
D. Remove hoses going to mixing chamber after tagging them. Make sure you do not lose the fiber washers on the
hose nut fittings.
E. With the mixing chamber upright in the vise, reach into the mixing chamber and grasp the tube portion of the orifice
plate assembly and push the assembly out through the base.
F. Remove the base cap.
G. Position a container under the chamber and remove the orifice plate, and shake the mixing chamber, causing the
powder to fall into the container
H. Clean the orifice plate, if required, with a fine wire brush and low pressure compressed air. Replace the gasket.
To reassemble, reverse the above procedure, making certain the base cap gasket is properly seated and the chamber
located to its scribed position. Clean away any powder that has fallen into the vibrator assembly or Unit itself.
16
Section 5: Service Tips
FLOW DIFFICULTIES
Powder flow difficulties may be caused by the following:
A. Worn or clogged nozzle tips.
B. Overfilled or nearly empty mixing chambers. Both conditions can cause an increase in powder flow. When the foot
switch is first actuated an initial heavy burst of powder is usually seen for a fraction of a second. This momentary
heavy mix is normal. It is due to small amounts of settled powder in the line. A slightly heavier than normal flow is
also noticeable after the mixing chamber has been filled.
C. Reused, contaminated, or improper powders. Such powders can decrease flow or clog the Unit completely,
especially at the mixing chamber orifices and at the hand piece nozzle. Never reuse powder. Use of Airbrasive’s
ABRASIVE Powders exclusively is recommended. We strongly recommend against the use of other commercial
powders because they are rarely classified adequately for use with the AIRBRASIVE apparatus, causing needless
maintenance and repairs. They may also have toxic substances present which could be harmful to your health.
D. Insufficient nozzle pressure, usually due to leaks, will reduce cutting speed.
E. Leaks around the mixing chamber, auxiliary chamber cap, and at fittings may increase powder flow. This condition
exists especially at low voltage (Powder Flow control knob set at lower range) and when the footswitch is actuated
intermittently every second or so.
F. Leaks around the base of the mixing chamber can result in decreased powder flow.
G. Visible leaks which can be detected by the pressure of powder.
H. Inoperative vibrator caused by broken, loose, or shorted magnetic coil leads.
I. Loose or broken vibrator springs or improper vibrator adjustment.
TESTING FOR LEAKS
Leakage may affect its performance and cause an excessive use of powder. The following service tips should be observed:
A. To check for total system leakage, turn on air pressure until the system is pressurized. Shut off the external air
supply valve and observe the Chamber Pressure Setting gauge. If pressure does not drop more than 15 PSI during
five minutes, the system leakage is less than one cubic foot per hour. This is negligible.
B. Most leaks are traced by ear, touch, or the use of soap and water. The presence of powder can indicate a leak.
C. To check for leakage at the auxiliary chamber top cover, have the chamber pressurized, and apply soap and water.
Look for leakage bubbles. Be certain to wipe off all traces of the soap after test completion.
D. Auxiliary chamber and mixing chamber gaskets are subject to leakage and require periodic replacement.
E. Make certain that the small nylon gaskets in the hose fittings are in place.
F. With the system pressurized and the air pinch valve tube closed, leakage through the pinch valve tube should not
exceed three bubbles per second with the nozzle tip immersed in water.
17
Section 6: Troubleshooting
TROUBLE
POSSIBLE CAUSE
REMEDY
1. With SYSTEM POWER ON/OFF
switch "On", switch doesn’t light.
a. Blown back panel fuse.
a. Replace fuse.
b. Switch burnt out.
b. Replace switch.
c. No input power.
c. Check external input power.
2. With SYSTEM POWER ON/OFF
switch "On" and with external air
connected to unit, rotation of Chamber
Pressure Adjustment does not change
PSI reading on Chamber Pressure
Setting.
a. Inoperative air pressure
regulator.
a. Turn Powder Regulation Adjustment fully
counterclockwise. Operate footswitch and
check for air flow at nozzle tip. Vary
Chamber Pressure from fully
counterclockwise to fully clockwise. A
definite change in air flow should be noted
at the nozzle tip as the knob is rotated its full
range. If not, replace air pressure regulator.
b. Inoperative air pressure
gauge.
b. Replace gauge.
3. Traces of powder at pinch valve.
a. Ruptured air pinch tube.
a. Replace tube (see page 20).
4. No air flow at nozzle tip with unit on
and foot switch actuated. (Chamber
Pressure gauge shows PSI.)
a. Nozzle tip clogged.
a. Clean nozzle tip.
b. Inoperative pinch valve
solenoid.
b. Check solenoid operation.
5. Air flow at nozzle tip when
Continuous Powder Flow/Foot Switch
Activated switch is in foot switch
position and foot switch is not actuated.
a. Shorted foot switch.
a. Check foot switch operation (See
Schematic: page 24).
b. Loss of air supply from
pinch solenoid regulator to
pinch solenoid valve.
b. Remove hose from bottom of pinch valve
and check for air flow. If no air flow, try to
adjust pinch solenoid regulator; if there is air
flow, remove and check pinch valve
assembly (See page 20).
6. Vibrator Inoperative
a. Open rectifier
a. Connect good rectifier in parallel with
rectifier on unit (see schematic page 24). If
vibrator operates, replace bad rectifier.
b. Open Powder Regulation
adjustment rheostat
b. Check operation of rheostat.
c. Vibrator magnetic coil burnt
out.
c. Replace vibrator assembly.
7. No powder flow from mixing
chamber.
a. Clogged orifice plate in
mixing chamber.
a. Remove, disassemble, and clean mixing
chamber (see page 22).
8. Powder spray from nozzle tip loses
definition.
a. Worn nozzle tip.
a. Replace nozzle tip.
18
PINCH VALVE ASSEMBLY (AR142Z1)
1
Screw, Knurled (2)
AR113
8
Spring
AR126
2
Block, top
AR119
9
Depressor
AR129
3
Hose fitting (2)
AQ130X
10
Diaphragm
AR121
4
Pinch valve
AR142
11
Plunger
AR115
5
Screw, special (2)
AF126
12
O-ring
AO118
6
Block, bottom
AR112
13
Body
AR171
7
Sleeve
AR117
19
AUXILIARY CHAMBER AND TOP COVER ASSEMBLY
1
Cap Assembly
AC124X
4
Tee Assembly
AQ146X
2
“O” Ring
AO105
5
Coupling
AC115
3
Chamber
AC107
20
MIXING CHAMBER ASSEMBLY
1
Nut Cap
AF402
5
Orifice Plate Assembly
AC106X2
2
Cap Assembly
AC112X
6
Gasket
AO108
3
Gasket
AO111
7
Base Cap
AC114
4
Mixing Chamber
AC118
8
Screw
AF105A
4A
Nipple Assembly
AQ137X
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