Friction Stir Welding Manual
Vanderbilt Welding and Automation Laboratory
Estevan L. Bunker
Paul A. Fleming
Thomas BloodworthTable of Contents
I. User’s Manual: Operation of Friction Stir Welding (FSW) Machinery
 Welding Operation
 Manual/Non-Automated Welding Operation
i.
Manual Welding Operation
ii.
Manual Motor Drive Operation
 Safety
 Accident Avoidance
II. Components of Friction Stir Welding Machinery
 Milling Machine
i.
Internal Motor
ii.
Installing and Using Manual/Internal Controls
iii. Backing Plate
iv.
Safety Door
 Motors and Dynamometer
i.
Lateral Motor
ii.
Vertical Motor
iii. Traverse Motor
iv.
Spindle Motor
v.
Gear Ratios
vi.
Dynamometer
 Computers and Sensor Box
i.
Computers
ii.
Sensor Box
iii. Sensor Box Software
 Maintenance and Other Systems
i.
Lubricator
1
ii.
iii.
Motor Lubrication
Spindle Head Adjustments
III. Appendices
1. Component Specs
1.1 NI-DAQ Boards
1.2 RS-485 Adapter
1.3 Vertical Magnetic Strip Decoder
1.4 Motor Drives
1.5 Ethernet Box
2. Network Schematic
3. Power Supply Schematic
4. Sensor Box Wiring SchematicI. User’s Manual:
Operation of FSW
Machinery
Welding Operation
In order to operate the FSW machinery, it is imperative that every step be followed in
sequential order and not a single one overlooked or ignored.
1. Install the tool into the milling machine by first inserting it under the spindle which is
attached to the dynamometer, and then using an Allen wrench to tighten the set
screws in the spindle. Be sure that the flat area of the tool is lined up with the set
screws so that proper installation is done. When the materials have all been set into
place correctly, the poly-carbonate door must be closed to begin welding and to
guarantee the proper level of safety (See Figure 2).
Dynamometer
Setscrew
hole
Figure 1. Dynamometer and tool
attachment
2
2. All of the fuse boxes for the motor drives and the dynamometer (switch on back of
dynamometer signal conditioner) must be turned on (See Figure 3 and 4). The extra
gray power plug for the vertical motor should also be plugged in. These fuses are
typically turned off while the circuit breakers on the other side of the room that
control current into the fuses are normally on.
Figure 3. Fuse boxes on
wall
Switches to be flipped
3
Plug for gray
cord
Figure 4. Dynamometer Signal
Condition
3. For the sensor box, the power strip on the right hand wall must be switched on and
each of the outlets containing a plug must also be switched on if it has not already
been done. Doing this should provide power to the Ethernet and lubricator as well
(See Figures 5 and 6). The Ethernet should be plugged into the sensor box if it has
not already been so done.
Main power
switch to be
turned on
3 switches to
be turned on
Sensor box
Figure 5. Power strip and sensor box
4
Power cord plugged in
to sensor box
Figure 6. Sensor box with power plugged in
4. Turn the Control and Dyno computers on (See Figure 7). The clocks for both
computers must be synchronized by double-clicking “internetconfig.bat”, then
“Atomic Clock Sync”, and click “Ping Now.” Exit the program and then doubleclick “weldconfig.bat”. The clocks should now be synched correctly to ensure proper
data collection.
5. Click on WeldController on the Control computer to bring up the program. The
program screen should be orange, indicating the program does not yet detect the
necessary components to proceed. Also, click on DYNOSYNC on the Dyno
computer to start the dynamometer (See Figure 9). The other Dynamometer program,
DYNO FAST, can be used to record force data if the spindle speed is set close to
2000 rpm. This program will yield more reliable data at higher speeds than the
original DYNOSYNC program.
Extra Computer
Control
Dyno
5
Figure 7. Computers
6. On the left side of the control program, the buttons “Sensor”, “Dyno”, “Traverse”,
“Spindle”, and “Lateral” should be listed. First connect to each of the four motor
drives through the connect buttons. Next connect to the dyno computer, checking
both computers to make sure connection successful. Finally, connect to the sensor
box. This connection informs the user to zero the vertical sensor, which must be done
straight away.
Auto-Zero button
Shows all systems
are connected
Figure 8. Control screen
6
Adjustable parameters
Figure 9. Dyno screen
7. In order for the vertical parameters to be correctly referenced, the vertical axis must
be zeroed. The sensor box waits for this process to be done and will eventually time
out if not done in time. The vertical motor must be set to continuous on the Control
and the velocity set to a not overly fast speed (no more than 5). Then, locate the
plastic strip next to the magnetic strip on the left side of the milling machine and
move the vertical motor so it may pass this plastic mark (See Figure 10). Pay careful
attention for the tool probe not to hit the table by raising the stage to high or going to
low and colliding with the floor. Zeroing should clear the orange screen and indicate
the vertical axis has been zeroed.
Plastic strip
to zero the
encoder
Magnetic
strip encoder
Figure 10. Vertical magnetic strip encoder
7
8. Parameters for the weld must be set in each of the motor interfaces to ensure a proper
weld (See Figure 8). Parameters include information that tells the system information
such as the limits of stage travel and where to start and end welds If there are
previous parameters that have been saved, they can be uploaded from a file by
clicking “Load parameters” and highlighting the appropriate file. To choose the
parameters:
 For the traverse, set the start, stop and Auto-Zero locations. Adjust limits
if need be. The start parameter is the location where the tool is set during
the Home process, and there should be about 0.25 in. of space between the
material and tool shoulder. The stop height is where the tool will stop and
this should also leave the same amount of room. The Auto-Zero position
is the point where the system will go to automatically auto-zero during
weld cycles if that option is selected and should align shoulder of the tool
with the end of the material to be welded.
 For vertical, set the return as a vertical position where the tool can move
freely in the x and y directions without colliding with the clamps. The
change height should be a very low stage position such that it is easy to
change out material. Weld height should be set by Auto-Zero (step 10).
Limits should also be taken into consideration. Height definitions can be
found in section 2, under Vertical Motor.
 For lateral, make adjustments if needed, but the parameters for normal
welds should be sufficient.
 Enter values for welding information such as file-names, rotation and
traverse speeds in the appropriate boxes in welding parameters and
recording parameters.
 These parameters can be saved as well for future use.
BE CAREFUL WHICH PARAMETERS YOU SET AS TO NOT RUIN
THE MACHINE.
9. After the lateral position has been set, the lateral brake should be in the engaged
position (to the left) to reduce any unnecessary lateral movement (See Figure 11).
Not keeping the brake in the on position can lead to inaccurate data collection and
damage to the milling machine. Be careful not to move the lateral string
potentiometer when adjusting the break.
Manual
hand-crank
8
Brake lever in
the on position
10. Adjust the tool’s position directly above where the shoulder of the tool would touch
the edge of the sample material. Slowly raise the stage close to the probe. Run the
auto-zero sequence button for the mill machine to find the height of the sample that is
secured on the back plate (See Figure 8). During the Auto-Zero sequence, the table
may have to be adjusted by turning the wheel on the left-hand side of the table to
avoid the probe hitting the sample (See Figure 11).
It should be pointed out that after the first weld of the day, if more welds are to be
run, this is the point the user comes to begin a second weld, the preceding steps need
only be done for system start-up.
11. On the bottom left of the WeldController program there is a section to save the data in
an appropriate file and group name. If this hasn't already been set, set these values.
When the necessary changes are made to the name of each, click Submit Changes in
order to relay the new information to the dynamometer (See Figure 12).
Lubricator button
Weld
button
Group and file name Figure 12. Control screen 2
9
Go Home button
12. Click Go Home on the bottom right of the WeldController program for the mill
machine to move to the starting position (See Figure 12). It is important to monitor
the machine as it is moving to the Home position to ensure nothing collides along the
way. Before any welding should take place, check the plunge depth by sliding the
steel disk of 0.01 in. under the probe. This distance between the tool and backing
plate is called the welding ligament. If the disc slides under easily then the machine
is ready to proceed. If not, the probe is too close to the backing plate.
13. If it is the first weld of the day, the lubricator must be run on the mill machine to
ensure proper equipment operation. To do this, turn the nozzle on the nitrogen gas
tank that is located on the right side of the room (See Figure 13). The pressure from
the tank should measure around 50 psi on the left pressure gauge; turn the regulator if
adjustment is needed. After the gas is ready, turn on the fume hood using the switch
found next to the fuse box by the door. There is also a pressure indicator on the
Control panel as another means of monitoring pressure. On the Control, turn on
lubricator for about 40-50 sec or until motion can be seen about 2/3 down the tubing
that leads to the dynamometer, then shut the lubricator off by the Control computer.
(See Figures 12 and 14).
Figure 13. Gas tanks
Watch for
movement here
10
Figure 14. Lubricator
Tubing
14. Double-check to make sure everything is suitable for the weld to take place and
nothing has the potential to be damaged. Once everything has been inspected,
then the next step may be started.
15. Position one person at the Control computer and another person should stand near the
table by the red distress button in case anything goes wrong. Once both are ready,
start the weld by clicking “WELD”.
16. Data will start to collect on the Dyno screen and the spindle will start up. If the
Dwell box has been checked (and virtually always it is) then the following procedure
will occur. When the tool gets to spinning at the correct velocity, it will begin to
move in to the material for a small distance. Then, it will stop for about 3 seconds
and proceed to weld until it is done.
17. When the weld is complete, turn off the gas as soon as possible to prevent leakage.
The machine moves to change height so the sample can be removed and the data
examined. The computer will then ask if the next sample is ready to be welded;
clicking yes will prompt the machine to go to the pre-set Home position.
18. The sample can then be labeled for further research.
19. The temperature of the dynamometer must be monitored every couple of welds to
ensure it does not exceed 40 C. Temperatures over this limit have the potential to do
damage to the dynamometer.
20. When finished welding, turn off the motors, fume hood, and dynamometer. To
completely shut down the computer programs:
 Hit ctrl-alt-delete and click on “Processes” tab
 Select “weldcontrol” on the Control computer and “dyno” on the Dyno
computer and click “End Process” for both (See Figure 15).
11
Manual/Non-Automated Welding Operation
Manual Welding Operation
Before the welding operation was automated, the entire process was run manually. This
technique required manipulation of the motor drives, levers, and brakes that were once
present on the milling machine. In the event that there is a software crash of the
WeldController program or sensor box, then the operation must revert back to the manual
process. The following steps illustrate the process of welding without the use of any
computer automation.
1. Install the tool into the milling machine by first inserting it under the spindle which is
attached to the dynamometer, and then using an Allen wrench to tighten the set
screws in the spindle. Be sure that the flat area of the tool is lined up with the set
screws so that proper installation is done. When the materials have all been set into
place correctly, the poly-carbonate door must be closed to begin welding and to
guarantee the proper level of safety (See Figure 2).
2. All of the fuse boxes for the motor drives and the dynamometer (switch on back of
dynamometer signal conditioner) must be turned on (See Figure 3 and 4). These
fuses are typically turned off while the circuit breakers on the other side of the room
that control current into the fuses are normally on.
3. Without any automation, it is better that the vertical motor and motor drive are not
used for welding because the zeroing process is safer for the machinery when done
manually. Since the motor has been attached to the vertical worm drive in the milling
machine through an external gear system, it is necessary to remove the entire gear
system and metal cover and install the manual cranks. After the external gear system
has been removed, the manual hand crank must be installed by following the
12
instructions listed in the section Installing and Using Manual/Internal Controls.
The manual hand crank can then be turned to adjust the height of the table anytime
during the weld.
4. Turn on the Dyno computer and click on the DYNO icon on the very bottom left of
the screen (by the Start button) to start the dynamometer. This is the program is run
on the software that was provided by Kistler when the dynamometer was purchased.
This software and its operating instructions can be found in the Kistler box which sits
on the bookshelves.
5. The lateral position for the weld may be set by manually operating the lateral motor
drive. This motor drive is the smallest one on the wall to the right of the milling
machine. Since the position cannot be found automatically, it must be estimated by
sight. This position can be locked in place by securing the brake into the on position
under the left side of the table (See Figure 11). Not keeping the brake in the on
position can lead to inaccurate date collection and damage to the milling machine.
6. Adjust the tool’s position directly above where the shoulder of the tool would touch
the edge of the sample material. The next step in the process is zeroing the weld
height for the milling machine by finding the highest height possible before the
dynamometer can detect any force on the z-axis. To do this, slowly raise the stage to
the probe by turning the vertical hand crank while monitoring the dynamometer
program for any registered forces on the z-axis. When there is the slightest indication
of a z-axis force, the height of the stage must then be lowered just slightly until the
dynamometer loses the reading. This process of raising and lowering the stage in
very small intervals must be done until the correct height is found right before there is
any force placed on the z-axis. During the zeroing sequence, the table may have to be
adjusted by turning the wheel on the left-hand side of the table to avoid the probe
hitting the sample (See Figure 11).
*It should be pointed out that after the first weld of the day, if more welds are to be run,
this is the point the user comes to begin a second weld, the preceding steps need only be
done for system start-up.
7. The traverse motor drive must be operated manually for the mill machine to move to
the starting (Home) position (See Figure 12). This location must also be sighted since
there is no automation. It is important to monitor the machine as it is moving to the
Home position to ensure nothing collides along the way. Also, the plunge depth must
be added during this process, so the table height must be adjusted using the manual
vertical crank. Before any welding should take place, check the plunge depth by
sliding the steel disk of 0.01 in. under the probe. This distance between the tool and
backing plate is called the welding ligament. If the disc slides under easily then the
machine is ready to proceed. If not, the probe is too close to the backing plate.
8. If it is the first weld of the day, the lubricator must be run on the mill machine to
ensure proper equipment operation. To do this, turn the nozzle on the nitrogen gas
tank that is located on the right side of the room (See Figure 13). The pressure from
the tank should measure around 50 psi on the left pressure gauge; turn the regulator if
13
adjustment is needed. After the gas is ready, turn on the fume hood using the switch
found next to the circuit breaker by the door. Turn on lubricator by plugging its
power cord into an outlet for about 40-50 sec or until motion can be seen about 2/3
down the tubing that leads to the dynamometer (See Figure 14).
9. Double-check to make sure everything is suitable for the weld to take place and
nothing has the potential to be damaged. Once everything has been inspected,
then the next step may be started.
10. In order for the weld process to begin, there needs to be one person assigned to
operate the spindle motor drive and traverse motor drives, one person assigned to
operate the manual traverse hand crank and one person to monitor the Dyno
computer. The frequencies for the spindle and traverse motor drives should already
be set to ensure there are no mistakes made during the welding itself.
11. Begin welding by having the person assigned to the motor drives press the green start
button on the spindle motor drive and allow for it to begin spinning at the necessary
speed. After the dynamometer begins to spin, the person assigned to the Dyno
computer should begin the dynamometer data collection on the Kistler program.
12. When the spindle reaches its full speed and data is starting to be recorded, the person
assigned to the traverse hand crank should begin to turn the hand crank to creep the
spindle into the material sample until the entire shoulder of the tool is in contact with
the material. The tool should stay in this position for 5-10 seconds to generate the
correct amount of heat for it to be a successful weld. After the 5-10 second waiting
period, the person assigned to the motor drives must press the green start button on
the traverse motor drive for it to begin moving.
13. When the weld is complete, turn off the gas as soon as possible to prevent leakage
and the spindle and traverse motor drives can be turned off by pressing their
respective red stop buttons.
14. The sample can then be labeled for further research.
15. The temperature of the dynamometer must be monitored every couple of welds to
ensure it does not exceed 40 C. Temperatures over this limit have the potential to do
damage to the dynamometer.
16. When finished welding, turn off the motor drives, fume hood, and dynamometer.
Manual Motor Drive Operation
During the manual welding process, it will be necessary to operate the spindle, lateral,
and traverse motor drives by hand. This process may seem simple, but it requires a lot of
calculations prior to the weld in order for it to be done correctly. Since would be too
difficult to run the vertical motor drive manually, it has not been included in the process.
The spindle, lateral, and traverse motor drives can be found on the wall on the right side
of the milling machine (Figure 23).
14
The spindle, lateral, and traverse motor drives are all frequency drives, meaning that the
motor drive will spin their respective motor depending on the frequency that is assigned.
Therefore, the higher the frequency that is assigned on the motor drive, the faster the
motor will spin. All three of the motor drives can run on a range of 0 to 60 HZ, with 60
HZ turning each motor at its fastest possible speed (Tables 3 and 5).
Since the motor drives offer a range of speeds and the speeds are only controlled by
changing frequencies, it is necessary that the experimenters do tests and calculations to
determine which frequency corresponds to each speed. This process will have to be done
for each motor and for each desired speed and should be stored in a table.
For the spindle motor drive, the calculations can be done by first determining the final
maximum rpm of the spindle head by taking into account the external gear ratio (Table
6), and then use a ratio of frequency to desired rpm to determine the necessary frequency.
For example, if the desired speed is half of the maximum speed, then only half of the
maximum frequency is needed. For the traverse and spindle motor drives, the first step is
to designate a known distance for each of the motor drives separately on the milling
machine and run the motor drives at different frequencies. The time that it takes each
motor to travel the standard distance on those different frequencies can be used to
determine the speeds of those motors. Before any of this experimentation may begin, one
must understand how to operate the motor drives.
Complete operation instructions for each of the motor drives can be found in their
respective Eaton/Cuttler-Hammer manual which can be found on the bookshelves. These
manuals guide the user through the complex systems of menus and sub-menus necessary
to operate each motor drive. However, power must first be provided to the motor drives
by first turning on the necessary fuses on the wall on the left side of the milling machine
(See Figure 3) before any work may be done.
15
Safety
With the milling machine, caution must be taken to guarantee no one is hurt and the
equipment is left undamaged. A few simple rules must therefore always be observed:
1. There must always be at least two people working together when preparing and
completing a weld. NO ONE IS ALLOWED TO WORK ALONE.
2. Protective eye-ware must always be worn while the machine is welding.
3. The fuse boxes should never be opened unless the person who does has extensive
knowledge and expertise of the subject.
4. Take caution around moving parts such as the belts, pulleys, and gears as some are
able to remove fingers and other appendages.
5. If the computer programs act in an unexpected way, the safest thing to do is to
completely close the programs via the ctrl-alt-del method described earlier and startup begun over. Continuing using a program that has produced odd errors is a very
dangerous thing to do, for instance communications between important components
may have been damaged without the operator noticing.
Further on this note, if communication between sensor box and control or dyno and
control is interrupted or disconnected, it is not advisable to try to reconnect them
without fully stopping each program (ctrl-alt-del) and restarting them and then
connecting. It is just not safe to do it any other way. However, it is ok to disconnect
and re-connect to the motor drives.
Accident Avoidance
The machinery and computer software for the milling machine and computers are not
completely fail-safe, so accident mitigation is vital in protecting all of the expensive
equipment. Accidents can be avoided by following the all of the steps listed in the
previous section but there are other unique problems that can occur and require
immediate action, such as:
 If the Control screen turns red, that signifies there is an error with something during
the weld. This issue is usually diagnosed by the computer itself and can be found at
the bottom of the screen. The red screen can be cleared by clicking “Clear Alarm,”
but the problem must be resolved before attempting to clear the alarm.
 Whenever there is a problem with the welding that is taking place, hit the abort button
on the Control screen or the red emergency button below the table. If the machinery
does not stop working, then the power switches to each of the motors must be shut off
immediately.
 The dynamometer is the most expensive piece of equipment in the FSW lab and
everything must be done to prevent it from being damaged. This means that the
probe and bottom of dynamometer cannot, under any circumstances, touch the
16
backplate because the contact can ruin the data recorded and the sensors attached.
Therefore, there are two scenarios that need to be looked out for:
1. If for some reason the vertical motor does not stop moving up after it is
supposed to or the abort buttons do not work, the gray plug for the vertical
motor by the motor drives must be pulled. IT IS EXTREMELY
IMPERATIVE THAT THIS INSTINCT COMES AS SECOND
NATURE WHEN ANYTHING GOES WRONG.
2. When the milling machine has set its Auto-Zero and has gone to the Home
position, it is necessary to check that the welding ligament is no less than 0.01
in. This may be tested with the small steel disk found in the lab or with a
paper of known thickness.
 The lower boundaries of movement for the vertical motor must also be carefully
monitored because if the motor moves to far down, the motor could disengage from
its nut. This would render the motor completely useless and would be incredibly
difficult to repair.
Wide shot of entire welding machinery
17
II. Components of FSW Machinery
Milling Machine
Internal Motor
The milling machine is a Kearney & Trecker 7.5 hp No. 2 Universal style milling
machine that has been modified to hold the FSW system (See Figure 16). Although no
milling takes place in the lab, the frame of the machine is perfectly built to accommodate
FSW welding. The internal motor of the milling machine was originally used to run all
of the worm drives that are a part of the machine, but now all of the worm drives are
driven by the attached external motors. The internal motor is now run on a very rare
basis for the purpose of lubricating the milling machine’s internal parts. To operate the
motor
1. Switch on the fuse-box for the internal machine that is located to the left of the
milling machine (See Figure 3).
2. Start the motor by first disengaging the clutch, and then pressing the start button.
Press the stop button after 20-40 seconds.
3. This should only be done only when the other motors (traverse, spindle,
lateral, and vertical) are turned off.
The parts for the machine can be found in the Kearney & Trecker parts catalog, in the
event of any further modifications to the machine.
On and off
buttons
Internal
motor
clutch
Figure 16. Internal Motor Clutch and Buttons
18
Installing and Using Manual/Internal Controls
If by chance the traverse and lateral motor drives fail, welding will have to continue by
re-installing the manual hand cranks and levers that were removed. If the spindle motor
drive breaks beyond repair, the only course of action would be to order a new one. Since
the milling machine was modified for automated FSW, there are motors now installed on
the milling machine where manual hand cranks, wheels, and levers used to reside. By reinstalling all the manual hand cranks, wheels, and levers, the milling machine will still be
capable to complete FSW. Turning the manual hand cranks and wheels by hand allows
the table of the milling machine to be adjusted. The levers allow the internal motor to
operate the vertical, lateral, and traverse worm drives when the internal motor is running.
Installing these levers can make the process of welding without any motor drives a little
more efficient as constant turning of the cranks and wheels would not be needed.
Before installing the manual hand cranks and wheels, the external vertical gear system
and cover must be removed (See Figure 17). The metal rods protruding from the milling
machine must remain on the machine because they are where the cranks and wheels shall
be placed. Taking off this external system grants access to the ports that are necessary for
hand crank and wheel installation. The manual hand cranks, wheels, and levers can be
found the parts box, which is a small cardboard box located in the cabinets on the
opposite side of the room from the milling machine (See Figure 18). The vertical hand
crank contains two parts: the hand crank and a relative distance gauge (See Figure 19).
The lateral hand wheel is only comprised of the wheel itself (See Figure 18). The levers
for the lateral and vertical worm drives are of the same design, while the lever for the
traverse worm drive consists of two unique components (See Figures 20 and 21).
Small
speed
gauge
Port for lateral
wheel
Port for
vertical hand
crank
Figure 17. Ports for Manual Controls
19
External gear
system to be
removed
Figure 18. Parts Box
Figure 19. Vertical Hand Crank
Lateral wheel
Hole to go
around
respective
port
Pin to
secure
attachment
of bottom
hole
Mount onto
metal rod
below
respective
port
Figure 20. Lateral and vertical
internal motor lever
Milling
machine
attachments
Lever
handle
Pins to
secure
attachments
Figure 21. Traverse internal
motor lever
20
The port where the vertical hand crank must be installed is located to the right of the
small green speed internal motor speed gauge (See Figure 17). To install the vertical
hand crank, first insert the relative distance gauge onto the port and secure it with its set
screw. After the gauge is attached, mount the lever by placing its middle hole around the
metal port rod, and then placing its lower hole onto the metal rod directly below the hand
crank port. This lever must be pinned into place onto the lower metal rod (all pins should
be located in the parts box). The hand crank can then be placed on to the metal port rod
and secured into place using its set screw. This final assembly allows for manual and
internal manipulation of the vertical worm drive (See Figure 24).
The port for the lateral hand wheel is the next port to the right of the vertical hand crank
port. The lever for the internal motor to control the lateral direction is mounted in the
exact same way as the vertical lever. The hand wheel only needs to be mounted onto this
port and secured with a set screw (any and all set screws should be located in the parts
box). This assembly also allows for the manual and internal manipulation of the lateral
worm drive (See Figure 24).
There are also ports located on the bottom left side of the milling machine by the lateral
motor that can also house the manual controls for the vertical and lateral directions (See
Figure 22). The port on the left is designated for the lateral direction and the port on the
right is designated for the vertical direction.
Port for
vertical
crank
Port for
lateral
wheel
Figure 22. Side ports for manual
controls
The internal motor lever for the traverse is comprised of two parts: the handle of lever
and milling machine attachment. The area for the lever to be installed is located on the
front edge of the table, and it looks like a small gray cylinder protruding up towards the
safety door (See Figure 23). To attach the lever, first position the milling machine
attachment onto the gray cylinder and fasten them together with the necessary pin.
Position the handle of the lever onto the milling machine attachment and fasten these two
components with the necessary pin as well (See Figure 24 and all the pins should be
located in the parts box).
To make adjustments with the manual controls on the milling machine, just turn the hand
crank or wheel in the correct direction to move the table to the desired location. It is
21
important to not adjust any of the worm drives outside of their operating limits as this
may require very difficult maintenance to repair.
Gray cylinder
to attach lever
Figure 23. Attachment area for
traverse internal motor lever
Traverse
internal
motor
lever
Lateral
wheel
and
internal
motor
lever
Small
speed
gauge
Vertical
internal
motor
lever
Figure 24. Model of re-installation of manual controls on
milling machine
To use the internal motor to operate the worm drives in all three directions:
1. First set the small speed gauge on the left hand side of milling machine to the desired
speed (See Figure 24). When using the levers to adjust the table, they will all move at
this speed. The numbers listed on the small speed gauge are in inches per minute, and
the gauge has a range from 0.25 in/min to 60 in/min.
22
2. Start the internal motor following the instructions listed in the previous section.
3. The internal motor levers that are attached on the vertical hand crank and lateral
wheel can be moved from their neutral (middle) position to the right or the left, which
engages the motor to move the table in the respective direction. Experimentation of
which direction to move the levers to induce the correct table movement may be
necessary.
4. The traverse lever for the internal motor can also be moved to the right or the left to
use the motor to make the correct adjustments. Experimentation of which direction to
move this lever to induce the correct table movement may be necessary as well.
5. If faster movement of the table is desired only for a short period of time while using
the internal motor levers, the long lever on the bottom right side of the milling
machine can be used to increase the speed of movement in any direction. To do this,
just simply pull up and hold onto the long lever to increase the speed to the desired
rate while using one of the internal motor levers. The higher the long lever is pulled,
the faster the table will move. It is important to note that the increased speed is
unknown when the lever is pulled because it is not an absolute speed increase, it is
merely relative.
Backing Plate
The backing plate sits on the table of the milling machine and it is the location where
welding samples are securely placed as to not move during the weld (See Figure 17).
Table 1. Backing Plate Material and Dimensions*
Material
Length
Width
Cold-rolled steel
24 in.
7 in.
Height
1 in.
*Dimensions may be modified depending on the research and/or experiment that are
being done.
Figure 25. Backing plate screwed into table
23
Safety Door
The safety door helps protect the users of the FSW machine from any harmful pieces of
machinery that may fly off the spindle while the weld is taking place (See Figure 2). The
safety door is made of two clear polycarbonate sheets that were ordered from McMasterCarr. The width of the door has been calculated to withstand almost any collision from
any of the pieces that have a chance of flying off the spindle, but caution must still be
taken during the welding process. The other component of the safety door is the pressure
sensor which runs to the Control computer, and the computer must detect that the door is
closed before any weld is to proceed. However once the weld starts, it may be opened if
a more detailed look is needed (However, this is very dangerous). To detect that the
switch is closed, the pressure sensor sends a digital signal to the sensor box, which relays
it to the Control computer via an Ethernet connection.
Table 2. Safety Door Materials and Dimensions
Material
Length
Clear polycarbonate
48 in.
Width
12 in.
Height
0.5 in.
Motors and Dynamometer
Lateral Motor
The lateral motor on the milling machine drives the stage laterally, or in other words,
perpendicular to the weld path. It is driven through a gear box which is coupled to the
internal worm drive in the table and it is the gray motor located on the bottom left side of
the milling machine.
The system has two methods for determining lateral position, a string potentiometer
attached to the stage and through a rotary encoder fixed to the lateral motor. For most
users, only the absolute position of the stage returned by the string encoder is needed,
whereas the relative motor position returned by the encoder are only needed for fine
control.
The digital signals from the disc encoder are sent back to the Control computer, through a
NI-DAQ board which connects to the computer through a USB port. The analog signals
from the potentiometer are sent back to the sensor box.
The center line for the welding must be manually centered using the lateral motor on the
Control panel. During the welding, there is a chance the lateral position may move, so it
is necessary to turn on the brake to prevent this from happening (See Figure 11). The
motor drive for lateral motor can be found on the wall to the right of the milling machine
and runs off of 480 V, which is fused and connected to a 480V circuit breaker in another
room (See Figure 31). The specs for the lateral motor can be found in Table 3.
24
Table 3. Specifications for Lateral and Traverse Motors*
Manufactur
Hp
Frame
Type
Design
er
U.S.
TF GDY
Electronic
1.00
143T-80
B
TE
Motors
Final
Motor
Volts
Amps
HZ
RPM
RPM
230/460
3.6/1.8
280
1750
60
Lateral
Traverse
Minimum
Maximum
Speed
Speed
(inches per
(ipm)
minute)
1.7 ipm
1.4 ipm
Code
Gear
Ratio
L
6.02
PH
3
Insul.
Class
B
*The lateral and traverse motors are identical.
Optical rotary
encoder
Figure 26. Lateral motor and encoder
Vertical Motor
The vertical motor uses a belt and gear which turns a worm drive to adjust the height of
the table before and after welding and is located behind the metal plating on the left side
of the milling machine (See Figure 27).
The system uses the Renishaw linear encoder to monitor vertical position. This sensor
returns to the sensor box a digital signal indicating vertical position.
25
There are three heights set by the user for weld sequences:
1. Weld height: This is the height where the tool shoulder just contacts the material.
This height is automatically found by the Auto-Zero function on the Control
screen. The system welds at a height of weld height + plunge depth.
2. Return height: Safe height at which the lateral and traverse motors make
adjustments during the Go Home and Auto-Zero sequences.
3. Change height: The height after welding at which samples can be easily changed
out and any work can be done on the table without much worry of damaging other
systems.
The vertical motor drive has two sources of power: 110 V supplied by the gray power
cord inserted in the wall outlet and 240 V which pases through 2 fuses and the circuit
breaker by the main door. This motor drive is found on wall, near the bottom, on the left
side of the milling machine (See Figure 30). Again, in the event of an emergency that
the vertical motor does not stop moving up or down, it is necessary to remove the
gray power cord from its socket to completely shut it down. The specs for the vertical
motor are found in Table 4.
Table 4. Vertical Motor Specifications
Manufacturer
Model number
Serial number
Volts
Maximum
Speed
(inches per
minute)
Parker
Compumotor
730 MTR
1831 R
240 and 110
5 ipm
Figure 27. Vertical motor
26
Traverse Motor
The traverse motor moves the table forward and back so the probe can pass through the
material during the welds and to make the necessary adjustments during the Go Home
and Auto-Zero sequences. For the motor, forward is moving right relative to the milling
machine and reverse is to the left. The traverse motor is the unprotected gear and belt
motor that is located at the right edge of the table (See Figure 28). This motor must
adjusts a large worm screw nut under the table to allow it to translate forwards and
backwards.
A small wire potentiometer that works exactly like the one attached to the lateral motor is
also attached to the traverse motor to detect traverse position. This wire potentiometer is
found under the right side of the table. The analog signals coming from the
potentiometer are relayed to the sensor box. The lateral motor will therefore be guided to
the parameters set in the Control screen.
The traverse motor drive for the traverse motor is powered by the 240 V supplied from
the fuse box, which is connected to the breaker by the door (See Figure 31). The motor is
identical to the lateral motor and the specs for the motor are found in Table 3.
Figure 28. Traverse Motor
Spindle Motor
The spindle motor is responsible for spinning the dynamometer and the tool during the
welding process. This motor is therefore very powerful as it spins the tool at very high
speeds to maintain the correct steady-state conditions for the weld. The tool shaft is spun
through a belt and gear system at the top of the milling machine (See Figure 29). The
RPM and spin direction of the spindle can be set through the Control screen before the
weld commences. The motor drive for the spindle is the largest on the wall and can be
found on the right side of the milling machine and is powered by 240 V supplied by the
breaker by the door (Figure 31). The specs for the spindle motor are found in Table 5.
27
Table 5. Spindle Motor Specifications
Manufacturer
Catalog
number
Frame
Spec.
number
Volts
230/
460
Amps
RPM
Rating
HZ
46/23
3450
40 C
AMBCONT.
60
Baldor
Industrial
VM2514T
254T
37F336
W451
G1
PH
Ser. F.
Code
Design
Insul.
Class
NEMA
NOM.
EFF.
P.F.
Bearings
DE
ODE
3
1.15
H
B
F
87.5%
91%
6309
6206
Maximum
Speed RPM
2000 RPM
Figure 29. Spindle motor
Figure 30. Vertical motor
drive
Traverse motor
drive
Spindle
motor drive
Figure 31. Motor drives
28
Lateral motor
drive
Gear Ratios
There are separate external gear ratios for the traverse, spindle, and vertical motors and
each of these ratios allows their respective motor to run at certain maximum and
minimum velocities. The maximum and minimum velocities therefore allow for a range
of different speeds, and one can be set in the parameters of the Control screen. These
gear ratios can also be changed to alter the maximum and minimum speeds by replacing
the gears and belts with a different set. Gear ratios and serial numbers for each of the
motors are found in Table 6.
New gears and belts may be ordered from the Emerson/Browning/Morse Components
Drive Products catalog (pg. D-3 and pg. D-11) that can be found on the bookcase shelves.
The gears and belts for the traverse and spindle motors are Poly-V, meaning the gears
have V-shaped indentations on the outside rim and the belts have V-shaded grooves to fit
into the gears. The nomenclature for each of the serial numbers can be found under
Table 6. Also, a bushing is only necessary if it is determined vital for the construction of
the gear system.
Table 6. External Gear Ratios
Driver
Driven
Gear
Gear
Belt Serial
Driver
Driven
Serial
Serial
Number** Gear Size Gear Size
Number* Number*
10J20G
10J106Q
520J10
2.0 in.
10.6 in.
Traverse
16J45P
16J60P
360J16
4.5 in.
6.0 in.
Spindle
Must be found by removing vertical gears cover plate
Vertical
*Gear Serial Number
Corresponds to
bushing needed
J signifies size of grooves
10J20G
Number of
grooves, i.e.
means 10
grooves
Diameter of gear in
inches, i.e. 2.0 in.
Last digit is in
tenths.
29
Ratio
1: 5.3
7: 12
**Belt Serial Number
J signifies size of
grooves
520J10
Length of belt in
inches, i.e. 52.0
in. Last digit is in
tenths.
Number of
grooves, i.e. 10
grooves
Dynamometer
The dynamometer records the data of the forces that are exerted on the probe in the x, y,
and z directions and records the moment exerted around the z-axis while the weld is
occurring. The official name for the dynamometer is Kistler Rotating Cutting Force
Dynamometer. This piece of equipment is the most important and most expensive,
therefore great care should be taken when handling it.
In order to record accurate data from each independent axis at all times, it was necessary
to install optical interrupters to monitor the position of the dynamometer. These optical
interrupters work by sending a signal every time the laser transmitter changes from
blocked to un-blocked. On the bottom of the dynamometer, there is a ring of optical
interrupters that protrude out every 36 degrees and serve the purpose of referencing the
location of the axes as the dynamometer spins (See Figure 32). This allows for the x and
y axes to be de-coupled, which provides an infinitely more accurate set of data. The
other set of optical interrupters on the dynamometer are used to keep track of the number
of revolutions it makes and is composed of just one piece of metal protruding from the
center (See Figure 32). For the DYNOFAST program, the force readings are taken only
once per revolution and not 10 times per revolution as the normal DYNOSYNC program
does.
The interrupters send digital signals back to the Dyno computer through a NI-DAQ
board, which allows the signals to transfer through USB port on the computer. The force
sensors on the dynamometer send back an analog signal to the Dyno signal conditioner
where they are altered and sent to the Dyno computer through a RS-232 connection. The
data from both of these signals show up on the screen for the Dyno program during the
weld (See Figure 9). As the data is being recorded, it is important to watch that the
moment about the z-axis does not reach above 30 for extended periods of time as the
dynamometer might be suffering damage from the weld. If this is the case, the weld
should be shut down and the problem examined.
The power for the dynamometer is obviously supplied by the electricity which runs from
its connection to the Dyno computer. More heavily detailed information can be found in
the Kistler Operation Instructions located in the bookcase.
30
If the DYNOSYNC program shows a positive z-axis force with a magnitude of about 100
when it is not welding, reset the Dynamometer by pressing Force Dyno Reset (See
Figure). If the positive z-axis force remains, then the DYNOSYNC program and Signal
Conditioner both must be rebooted. Check the Processes tab in the Windows Task
Manager to confirm the DYNOSYNC program has been completely shut down (See
Figure 15).
Laser transmitter
Axis
reference
interrupters
Revolution
interrupter
Figure 32. Optical interrupters on
dynamometer
Computers and Sensor Box
Computers
There are two computers for the FSW system and each serves a very important function.
The Control computer automates the entire welding procedure by making the correct
position adjustments to each motor as well as controlling the lubricator for the spindle
head. The Dyno computer is connected to the dynamometer on the spindle head and
records the data of the forces that act on the spindle head during the welding process.
There is a separate computer that was used for the Sound, but there is virtually no use for
the computer anymore. Each of these computers can be found on the left side of the
milling machine (See Figure 7).
The Control computer controls all the motors by communicating with their motor drives.
The control computer is connected to the lateral, traverse, and spindle motor drives
through a RS-485 adaptor board, and this board is finally connected to the computer via
USB. The vertical motor drive is connected straight to the Control computer through a
RS-232 connection. Also, the lateral disc encoder is connected to the computer through a
NI-DAQ board, which receives the digital signals from the encoder and transfers them
through a USB connection. The program for running the welding process is named
WeldController and can be found on the desktop of the Control computer.
31
The Dyno computer is also connected to the Control computer through an Ethernet
connection. This connection allows the Control computer to dictate where the force data
files can be stored by assigning the folder name to each set of data, and more information
for this procedure can also be found in Step 11 of the Welding Operation. The Dyno
computer is connected to the Dynamometer through the Dyno signal conditioner. Also,
the spindle shaft interrupters are connected to the Dyno computer through a NI-DAQ
board by a USB connection. This NI-DAQ board receives the digital signals from the
interrupters and relays them to the Dyno computer. The program for the running the
dynamometer is named DYNOSYNC and can be found on the desktop of the Dyno
computer.
Control IP Address: 10.10.6.101
Dynamometer IP Address: 10.10.6.102
Sensor Box
The sensor box is a very important piece of equipment which collects all the sensor data
and passes this information to the control computer via the ethernet. There are six
sensors attached to the sensor box which include: the traverse potentiometer, the lateral
potentiometer, the pressure for the lubricator, the safety door pressure, the emergency
button pressure, and the vertical magnetic strip encoder. The sensor box also connects to
a relay which powers the spindle shaft lubricator.
The components of the sensor box include: the power supply, the DC-DC converters, the
Wolf computer board, and of course the wires (See Figure 33). Each of these
components serves a distinct and important function in the process of sending signals
back to the Control computer. The power supply is very important in that it converts the
110 V AC current from the power strip outlet into 24 V, 1.3 A DC current because the
sensors run off of DC. Also, there are two DC converters; one converts the 24 V DC to
12 V DC and the other converts the 24 V DC to 5 V DC.
The wolf computer board has a number of input and output devices. It reads the
lubricator pressure switch, safety door switch, and emergency button using digital inputs.
It uses specialized digital inputs set to quad-decoders to read the vertical sensor. It uses
A/D converters to read the string pots. And finally it uses high-current outputs to drive
the relay which powers the spindle-shaft lubricator.
The wires inside the box are color-coded according to the following scheme:
Green = Ground
Blue = DC Ground
Black = AC Line
White = Neutral
Red = DC Power (either +5 +12 or +24V)
Other: Information lines
The only exception to the rule is that the brown wire from the safety door pressure switch
is for ground, not signal transfer.
32
The signals that the Wolf computer board receives from the sensors are transmitted to the
Control computer through an Ethernet ICP/IP connection. The sensor box has a
permanent address 10.10.6.100 and the computer is programmed to look for that address
once the Control program is ran.
The power for the sensor box comes from a 110 V AC outlet on the power strip located
on the floor by the right side of the milling machine (See Figure 5). The power from this
outlet goes into the side of the box by a CPC, so it is very important to check the CPC is
fully connected before proceeding with the welding process.
24 V to 12 V
converter
Wolf
computer
board
Power supply
24 V to 5 V
converter
Figure 33. Sensor Box Interior
Sensor Box Software
The software that runs the sensor box is written in Dynamic C and runs through
WolfWeldControl. In this program, all of the code to run the sensor box can be found.
This program runs by collecting signals from all of the sensors and then puts them into a
string to send back to the Control computer to read. If any changes need to be made to
the code to make the sensor box run more efficiently, this program will allow it to be
done.
Maintenance and Other Systems
Lubricator
The lubricator is responsible for lubricating the entire spindle head to allow it to spin
freely. Since it is imperative that the lubricator run for every weld, the lubricator is
automatically turned on by the Control computer when the weld begins. If it is the first
weld of the day, the lubricator must run for close to a minute prior to any welding by
pressing lubricator button on the Control screen (See Figure 12).
33
In order for the lubricator to operate, the nitrogen gas tank on the right side of the room
needs to be opened and the left pressure gauge should register very close to 50 psi. To
avoid wasting the nitrogen gas, the gas tanks should be opened right before the weld is to
begin and be closed right after the weld has finished. Then when welding begins, the
Control computer sends a signal to the lubricator to open the solenoid to allow a mixture
of oil and air to pass through the tubing. The pressure from the nitrogen gas forces this
mixture down the tubing and into the upper and lower thrust bearings in the spindle head.
The lubricator will automatically be shut off by the Control computer once the welding
stops.
The lubricator is connected to the sensor box through a relay station which is located on
the cart under the sensor box. This relay station sends a digital signal to the sensor box
and the signal is sent to the Control computer via an Ethernet connection.
To fill up the lubricator, remove the cap on the top right and pour oil into the hole. Pay
attention to the gauge in the front and do not fill past the demarcated line (See Figure 34).
Refilling of the lubricator must be done whenever it is deemed necessary by the team.
The oil used in the lubricator is an Ethyl lubricator DTE Oil Light Bearing and
Circulating Oil #ISO VG 32, and the bucket can be found in the corner on the opposite
side of the room of milling machine (See Figure 35). More oil can be ordered from
Mobil and the contact information for the office is
4451 Nashville Rd.
Franklin, KY 42134
270-586-8283
Solenoid
triggered
by
computer
Refill level
Figure 34. Lubricator machinery
34
Figure 35. Bucket of lubricator oil
Motor Lubrication
Lubrication for the traverse and lateral motors is also very important for maintaining the
system in working order, but it is very rare that this needs to be done. For these motors, it
is necessary to only refill the oil in the motors when it gets low. Since the motors are
used very lightly, the refilling of the lubricator should only occur about twice a year
(depending on use). The oil that should be used is Coastal Gear Oil 80W 90 (See Figure
37).
Bolt to
unscrew
for refill
Do not fill above
this bolt
Figure 36. Back of
Traverse motor
Since both motors are identical, the process for refilling the oil is the same simple
process. To refill the oil, just unscrew the bolt at the top of the secondary part of the
35
motor, and pour in the oil (See Figure 36). There are two bolts on the side of the motor
and the level of the highest one is the height that the oil should be filled. The amount is
very low, but it is all that is required.
Figure 37. Gear Oil for
traverse and lateral motors
Spindle Head Adjustments
If a change in the degree of the weld is desired, it must be done by adjusting the spindle
head itself. This can be done by first only loosening the four bolts on the spindle head
and then by pushing the spindle head in either clockwise or counter-clockwise direction
by the desired number of degrees (See Figure 38). There is a metal strip on the spindle
head which indicates the degree orientation of the tool and using this strip is necessary in
making precise changes.
36
Bolts that
should be
loosened
III. Appendices
1. Component Specs
1.1 NI-DAQ Boards
Lateral: National Instruments USB 6501
Dyno: National Instruments USB 6008
1.2 RS-485 Adaptor
ULinx RS-422/485 USB adaptor
1.3 Vertical Magnetic Strip
RENSHAW Serial# 4W3194
1.4 Motor Drives
Spindle: Eaton SVX-9000 Cat. # SVX020A1-2A1N1
Traverse: Eaton MVX9000 Cat. # MVX007A0-2
Lateral: Eaton MVX9000 Cat. # MVX001A0-4
Vertical: Compumotor, KH series, Brushless servo drive Model # KHX-250
1.5 Ethernet Box
Linksys 10/100 8-port Work group switch
37