HAMAR LASER Triple Scan L-743 User manual

Important Notices
Please Read First
Laser Warm Up
Your new laser has been calibrated while it is fully warmed up. In order to ensure proper
calibration, we recommend that you let your laser warm up for at least 30 minutes for
single-plane lasers (L-730 or L-740) and up to 45 minutes for multi-plane lasers (L-732, L-
742, L-733 and L-743).
This does not mean the laser spindles need to be rotating; only that the laser beam should
be turned on for the recommended time.
You can use your laser prior to the warm up time to buck it in (make it parallel) to your
references. However, doing this may result in some laser drift. Accordingly, if you use the
laser prior to the warm-up period, it is recommended that you go back and check your
references before you start taking the alignment measurements. For best results, do not
start taking measurements until the recommended warm time has passed.
It is always a good metrology practice to periodically check your reference points to ensure
the laser or the base (instrument stand, table or other supporting base) it sits upon has not
drifted. Please note that most drift problems are caused by what the laser sits upon, not
due to the laser drifting itself (after the warm up period).
Please call 1-800-826-6185 or [phone] if you have any questions or concerns.
CAUTION!
Surge Protection Strongly Recommended
To ensure the long life of your laser, it is important to plug the A/C adapter into a surge-
protected power source. Despite internal surge protection, a large power surge may cause the
laser diode to burn out, requiring the laser to be returned to the factory for extensive repair.
Failure to plug the A/C adapter into a surge-protected power source may void the warranty.

WARRANTY
Hamar Laser Instruments, Inc., warrants each instrument and other articles of
equipment manufactured by it to be free from defects in materials and
workmanship under normal use and service, its obligation under this warranty
being limited to making good at its factory any instrument and other article of
equipment which shall, within one year after shipment of each instrument and
other article of equipment to the original purchaser, be returned intact to Hamar
with transportation prepaid, and which Hamar’s examination shall disclose to
Hamar’s satisfaction to have been thus defective; other than this express
warranty, Hamar neither assumes nor authorizes any other persons to assume for
it any other liability or obligation in connection with the sale of its products.
This warranty is not applicable to instruments or other articles of equipment
manufactured by other companies and limited by a warranty extending for less
than one year. In such an event, the more limited warranty applies to said
instrument or article of equipment.
This warranty shall not apply to any instrument or other article of equipment
which shall have been repaired or altered outside the Hamar factory, nor which
has been subject to misuse, negligence, or use not in accord with instructions
furnished by the manufacturer.
The software described in this manual is furnished under a license agreement and
may be used or copied only in accordance with the terms of the agreement. It is
against the law to copy the software on any medium for any purpose other than
the purchaser's personal use.
The information in this manual is subject to change without notice. No part of
this manual may be reproduced by any means, electronic or mechanical, without
written permission from Hamar Laser Instruments, Inc.
© Copyright Hamar Laser Instruments, Incorporated, 2019
5 Ye Olde Road, Danbury, Connecticut 06810

Table of Contents
The L-743 Ultra-Precision Triple Scan®Laser............................................................................................. 1
The L-733 Precision Triple Scan®Laser ...................................................................................................... 3
The L-742 Dual Scan Ultra-Precision Roll Alignment Laser....................................................................... 4
The L-732 Dual Scan Precision Roll Alignment Laser ................................................................................ 5
Laser Controls............................................................................................................................................... 6
Differences in the Lasers........................................................................................................................... 6
Providing Power to the Laser.................................................................................................................... 7
Warming Up the Laser.............................................................................................................................. 7
Using the Control Panel ............................................................................................................................ 8
The Precision Level Vials............................................................................................................................. 9
Reading the Precision Level Vials ............................................................................................................ 9
Reading the L-740SP Split-Prism Level Vials.......................................................................................... 9
Calibrating the Level Vials ....................................................................................................................... 9
Zeroing the Targets........................................................................................................................ 10
Calculating the Calibration of the Level Vials – Roll Axis ........................................................... 10
Setting the First Level Vial – Roll Axis......................................................................................... 12
Calculating the Calibration of the Levels Vials – Pitch Axis ........................................................ 12
Setting the First Level Vial – Pitch Axis ....................................................................................... 13
Checking the Levels for Accuracy................................................................................................. 13
Measurement Overview .............................................................................................................................. 14
Selecting Reference Points on Machine Tools........................................................................................ 14
Selecting Reference Points on Process Mills.......................................................................................... 14
Measurement Summary .......................................................................................................................... 15
Measuring Straightness.................................................................................................................. 15
Measuring Flatness ........................................................................................................................ 16
Measuring Squareness ................................................................................................................... 16
Measuring Levelness ..................................................................................................................... 17
Measuring Parallelism ................................................................................................................... 17
Level to Earth Measurements ................................................................................................................. 17
Setting Up and Leveling the Laser................................................................................................. 17
Laser Buck-in.............................................................................................................................................. 18
Three Point Buck-In (Flatness) ............................................................................................................... 18
Three Point Buck-In Procedure Using One Target........................................................................ 18
Setting up the Equipment............................................................................................................... 18
Performing the Three Point Buck-In.............................................................................................. 19
Three Point Buck-In Procedure Using Multiple Targets ............................................................... 20
Two Point Buck-In (Straightness)........................................................................................................... 20
Normal versus Remote Buck-In.............................................................................................................. 21
Normal Buck-In ............................................................................................................................. 21
Remote Buck-In ............................................................................................................................. 22
Appendix A – Troubleshooting Guide........................................................................................................ 24
Appendix B – Equipment Drawings ........................................................................................................... 27
Appendix C – Interpreting the A-1519/1520 Type II Calibration Reports................................................. 31
Appendix D – Care and Cleaning of Target Optics .................................................................................... 33

1
The L-743 Ultra-Precision Triple Scan®Laser
The L-743 Ultra-Precision Triple Scan®Laser is
Hamar Laser’s most versatile and powerful
machine tool alignment laser. It has been designed
specifically for 3-5-axis machining centers to
measure and correct machine geometry. In most
cases, all it takes is one setup to measure flatness,
straightness, parallelism and squareness of the main
axes of most typical machining centers.
Since the system provides live measurements, any
errors that are found can be fixed with the same
setup. The laser mounts on a machine or stable base
so that the laser plane can project the measurement
reference out to 100 ft. (30.5 m) in radius for each
laser plane.
Applications: (for alignments with tolerances of 0.00002 in/ft or 0.0017 mm/m or greater)
•Machining centers (HBMs, VBMs, HMCs, VMCs,
VTLs, gantries and surface grinders)
•Automotive transfer-line wing bases
•Injection molding machines and presses
•Aircraft assembly (seat track alignment, setting water, butt and station planes, wing-to-body and body-
to-body join alignment, etc.)
Roll parallelism in:
•High-precision, laser and water-jet cutting machines
•Paper mills
•Film lines
•Circuit board drilling machines
•Printing presses
•Blown-film lines
Measuring and aligning:
•The flatness of almost any surface (squares, frames,
ways, flanges, circles, etc.)
•The squareness of up to 3 surfaces
•Measuring surfaces up to 200 ft. (61 m
) long with
one setup
•The parallelism of horizontal and verti
cal surfaces
even if those surfaces are 100 ft. (30.5 m) apart
•
Checking way twist and parallelism between
horizontal surfaces
•The straightness of horizontal and vertical
surfaces
•
The straightness and flatness of
horizontally and vertically traversing axes
•Checking plumb of a vertical surface up to
100 ft. (30.5 m)
•
Checking way twist and parallelism
between vertical surfaces
Warning!
Always operate the L-730 and L-740 series lasers described below in an upright position.
Do NOT invert!

2
Features
•3 continuously rotating laser planes with operational
range of 100 ft. (30.5 m) in radius.
•Instant on with virtually no warm-up
•Planes are mutually square to 1 arc sec (.00006 in/ft
or 0.005mm/m).
•Levels accurate to 1 arc second (.00006 in
/ft or
0.005mm/m).
•Targets provide live data display
•Uses A-1520 Single-
Axis Wireless Target with 1
Micron (.00004 in.) resolution for
higher accuracy
applications.
•Laser and targets fit into a small, portable shipping
case
•
Diode laser 2 times more stable than HeNe based
laser systems
•
Battery or AC powered
•Laser planes flat to ½ arc seconds (.00003
in/ft or 0.0025mm/m) in 180º sweep and ¼
arc second (.00001 in/ft or 0.0008mm/m) in
90º sweep).
•
Includes Pitch/Roll/Yaw base with coarse
and fine adjustments and lighted levels.
•Standard target: A-1519-2.4ZB Single-Axis
Wireless Target with 1 in. measuring range
and .0001 in. resolution.
•System uses Windows-
based software for
quickly recording and analyzing machine
geometry data
•Typical setup time 20 minutes or less
•Completely self-contained

3
The L-733 Precision Triple Scan®Laser
The L-733 Triple Scan Laser was specifically designed for
machining centers to measure and correct machine geometry.
It has all of the innovative and highly useful features of the L-
743 Ultra-Precision Triple Scan Laser, with lower accuracy
and a medium adjustment base. It is very useful for checking
the alignment of large fabrications or aligning large airplane
sections in aircraft manufacturing.
In most cases, all it takes is one setup to measure flatness,
straightness, parallelism and squareness. Since the system
provides live measurements, any errors that are found can be
fixed with the same setup. The laser mounts on a machine or
stable base so that the laser plane can project the measurement
reference out to 100 ft. (33 m) in radius for each laser plane.
Applications: (for alignments with tolerances of .0005 in/ft or (0.038 mm/m) or greater)
•Machining centers (HBM, VBM, VTL, VMC, HMC,
gantries, surface grinders)
•Water jet and laser cutting machines
•Leveling machine beds and ways
•Checking the alignment of large bearing surfaces and
fabrications
•Roll alignment (rubber, steel, textile and lower
accuracy film lines)
•Aircraft assembly (seat track alignment, setting water,
butt and station planes, wing-to-body and body-to-body
join alignment, etc.)
•Saw mills
•Vertical press alignment
Measuring and aligning:
•The flatness of almost any horizontal or vertical surface
(squares, frames, ways, flanges, circles, etc.) or axes
•The squareness of any 2 vertical surfaces or axes
•The straightness of vertical and horizontal axes
•Measuring surfaces up to 200 ft. (66 m) long with
one setup
•Way twist and parallelism between vertical or horizontal
surfaces
•The parallelism of vertical or horizontal surfaces,
even if those surfaces are 100 ft. (33 m) apart
•Way twist and parallelism between vertical or horizontal
surfaces
•The squareness of any vertical machine axis or
surface to horizontal axis or surface
•Checking plumb of a vertical surface up to 100 ft.
(33 m)
Features:
•Continuously rotating laser planes with operational
range of 100 ft. (33 m) in radius.
•Completely self-contained
•Laser planes flat to 2 arc seconds in 180º sweep and 1
arc-second in 90º sweep. Planes are mutually square
to 2 arc seconds.
•Standard target: A-1519-2.4ZB Single-Axis Wireless
Target providing live data display
•System uses Windows-
based software for quickly
recording and analyzing machine geometry data
•Typical setup time 20 minutes or less
•Diode laser 2 times more stable than HeNe-based laser
systems
•Includes Pitch/Roll/Yaw base with medium-
resolution adjustments and lighte
d levels. Levels
accurate to 2 arc seconds.
•Instant ON, with virtually no warm up
•Battery or AC powered

4
The L-742 Dual Scan Ultra-Precision Roll Alignment Laser
With two continuously sweeping, ultra-flat, orthogonal
laser planes, the L-742 is ideally suited to roll alignment
applications. The laser can be configured at the factory
to have either two vertical planes, or one horizontal and
one vertical plane, allowing a user to not only measure,
but also fix alignment problems in a fraction of the time
needed with conventional methods.
Using the L-742 you can quickly and easily check and
correct horizontal roll parallelism of even the tallest
process mills, pick up and check offset centerline
benchmarks, and perform similar alignments with
increased accuracy and shorter setup times.
Applications: (for alignments with tolerances of .00002 in/ft or 0.0017 mm/m or higher)
•Roll parallelism in paper mills, printing presses and
film lines
•Leveling almost any surface (squares, frames, ways,
flanges, circles, etc.
•Roll forming machines
•High-precision, laser and water-jet cutting machines
•Checking plumb of a vertical surface up to 100 ft.
(30.5 m)
•Measuring surfaces up to 200 ft. (61 m) long with one
setup
•Checking way twist and parallelism between
surfaces
•Circuit board drilling machines
Measuring and aligning:
•The flatness and straightness of almost any surface
(squares, frames, ways, flanges, circles, etc.)
•The flatness and straightness of horizontally and
vertically traversing axes
•The parallelism of vertical or horizontal surfaces, even
if those surfaces are 100 ft. (30.5 m) apart
•The squareness of any two surfaces
•The flatness and straightness of vertical surfaces

5
The L-732 Dual Scan Precision Roll Alignment Laser
Primarily designed for roll alignment and other similar
alignment applications that do not require the exacting
tolerances of the L-742 Ultra-Precision Laser, the L-732
Precision Dual Scan Laser also offers two automatically
rotating laser planes that can be configured at the factory
to have either two vertical planes, or one horizontal and
one vertical laser plane. The L-732 laser planes are flat
and square to 2 arc seconds (.00012 in/ft or 0.01 mm/m).
It comes with a pitch, roll and yaw adjustment base for
setting the laser planes parallel to reference points, 2-
arc-second level vials and a powerful magnet for
maximum stability.
Applications: (for alignments with tolerances of .00015 in/ft or (0.01 mm/m) or greater
•Normal or blown-film lines (roll alignment)
•Rubber (roll alignment)
•Leveling almost any surface (squares, frames, ways,
flanges, circles, etc.
•Laser cutting machines
•Water-jet cutting machines
•Checking plumb of a vertical surface up to 100 ft.
(30.5 m)
•Steel (roll alignment)
•Saw Mills
•Checking way twist and parallelism between
vertical surfaces
•Textiles (roll alignment)
Measuring and aligning:
•The flatness of almost any vertical surface (squares,
frames, ways, flanges, circles, etc.)
•The straightness of horizontally and vertically
traversing axes
•The parallelism of vertical or horizontal surfaces, even
if those surfaces are 100 ft. (30.5 m) apart
•The squareness of any two vertical surfaces
•The flatness and straightness of vertical surfaces
•Measuring surfaces up to 200 ft. (61 m) long with one
setup

6
Laser Controls
Differences in the Lasers
The differences in the four laser models discussed in this manual are as follows:
•Accuracy: the L-743 and L-742 are four times more accurate for flatness and two times more
accurate for squareness than the L-733 and L-732. The L-733 and L-732 have a pitch/roll/yaw base
with medium adjustments and the L-743 and L-742 have a pitch/roll/yaw base with both coarse and
fine adjustments (see Figure 1).
•Number of laser planes: the L-743 and the L-733 have three laser planes and the L-742 and L-732
have two laser planes that can be factory-configured for two vertical planes (wall/wall) or one vertical
and one horizontal plane (wall/ceiling).
When drawings are used to describe a procedure, the laser model will be identified in the caption.
However, the procedures themselves are essentially the same for all four lasers. Appendix A, beginning
on Page 24, provides detailed drawings and specifications for each laser model.
Figure 1 – L-733 Laser (left) and L-743 Laser (right) top and side views

7
Providing Power to the Laser
Power to the laser is supplied by either an external battery pack using four 9V cells, (Hamar Laser
recommends using alkaline or NiCad cells for best performance) or by a 115V AC adapter (see Figure 2
for the location of the battery pack/AC adapter connection on the laser control panel). The laser uses more
power with each additional scanner that is activated.
Warming Up the Laser
Your new laser has been calibrated while it is fully warmed up. In order to ensure proper calibration, we
recommend that you let your laser warm up for at least 30 minutes for single-plane lasers (L-730 or L-
740) and up to 45 minutes for multi-plane lasers (L-732, L-742, L-733 and L-743).
This does not mean the laser spindles need to be rotating; only that the laser beam should be turned on for
the recommended time.
You can use your laser prior to the warm up time to buck it in (make it parallel) to your references.
However, doing this may result in some laser drift. Accordingly, if you use the laser prior to the warm-up
period, it is recommended that you go back and check your references before you start taking the
alignment measurements. For best results, do not start taking measurements until the recommended warm
time has passed.
It is always a good metrology practice to periodically check your reference points to ensure the laser or
the base (instrument stand, table or other supporting base) it sits upon has not drifted. Please note that
most drift problems are caused by what the laser sits upon, not due to the laser drifting itself (after the
warm up period).
CAUTION!
Surge Protection Strongly Recommended
To ensure the long life of your laser, it is important to plug the A/C adapter into a surge-protected
power source. Despite internal surge protection, a large power surge may cause the laser diode to
burn out, requiring the laser to be returned to the factory for extensive repair. Failure to plug the
A/C adapter into a surge-protected power source may void the warranty.

8
Using the Control Panel
Figure 2 shows the control panel for the L-743 and
L-733 lasers, including the locations of:
•The battery pack/AC adapter connection
•The power switches and POWER ON
indicator for the laser
•The power switches for the individual
scanners
•The light for the precision level vials
Note: As of January 1, 2014, the level light
switch has been modified. The level light now
stays on permanently to increase stability and
allow the laser to warm up faster.
•The rotation speed control. This control slows
the scanner spin until you can see the laser
beam pass over the target (the farther away the
target is located, the slower the turret must
spin).
Figure 3 shows controls panel for the L-742 and L-732 lasers, both the “Wall-Wall” configuration with
two vertical laser planes, and the “Wall-Ceiling” configuration, with one vertical laser plane and one
horizontal laser plane.
Figure 3 – Laser Control Panels for the L-742 and L-732 Lasers. On the left is the “Wall-Wall” configuration, or two vertical laser planes. On
the right is the “Ceiling-Wall” configuration, or one vertical plane and one horizontal plane.
Figure 2 -- Laser Control Panel—L-743 and L-733 Lasers

9
The Precision Level Vials
Reading the Precision Level Vials
Secure the laser base to a metal surface by turning the locking
magnetic base ON. Once the laser is in position, power it on
and light the level vials (if necessary) using the LEVEL switch
located on the control panel. Use the adjustment knobs to bring
the bubbles to the center of both vials (see Figure 4).
When both the PITCH and ROLL vials are reading level, a
level beam can be scanned at 360 degrees with a .0003 in.
deviation per 10 ft.
Reading the L-740SP Split-Prism Level Vials
Once the laser unit is in position on the base, connect
power to the base power supply input jack and press the
red button to light the precision level vials. Use the
coarse alignment micrometers to bring the bubbles to the
center of the vials.
When the bubbles are close to the center, use the fine
adjustment micrometers to align the bubble halves to
each other in the viewing prism window (see Figure 5).
When both the long axis and short axis vials are reading
level, a level beam can be scanned at 360 degrees with a
.0003 in. deviation per 10 ft.
Calibrating the Level Vials
Note 1: This procedure calibrates only one level vial at
a time and must be repeated for the other axis.
Note 2: It is very important to warm up the laser for at
least 30 minutes before starting this procedure. It is also
very important to level both the Pitch and Roll axis level
vials during this procedure. Failure to do this makes it
nearly impossible to calibrate the levels.
The calibration procedure involves a series of steps to adjust the laser beam to be level to earth. Because
the leveling process is subject to so many variables, repeat the procedure to check for accuracy once the
initial readings are taken and adjustments are made. A typical sequence would be as follows:
•Determine the set point and set the first axis.
•Use the set point value to set the second axis.
•Check both the first and second axes. Reset the levels if necessary.
•If the levels are reset, make a final check to determine if the laser level error is acceptable.
Figure 4 – Precision Level Vial entered (top) and off
center (bottom)
Figure 5 –L-740SP Split-Prism Level Vial Assembly for L-
740 Series Lasers
Please Note!
Our level vials are designed to be calibrated by the customer. We cannot guarantee that the level
vials are calibrated when you receive the equipment because of movement during shipping. Please
follow the procedure below specific to the level vials on your laser.

10
When calibrating the precision level vials, work on a surface that is level to earth within .001 to .002 in/ft.
A surface that is 10 to 20 ft. in length is ideal. When calibrating to shorter surfaces, do so with the
readout set to the .0001 in. mode. If you are using the A-1519 or A-1520 Wireless Targets with the R-
1356 PDA or with Hamar Laser’s alignment programs, set the readout display through the software.
Figure 6 -- Laser and Target Setup for Calibrating the Precision Level Vials
Zeroing the Targets
The following sections refer frequently to “zeroing” the target. When a target is zeroed, the readout is
reset to zero at the point where the laser beam currently hits the target cell.
When using the A-1519/A-1520 Universal Targets, this is accomplished through the Read15 software (or
through Hamar Laser’s other alignment programs). This reading is stored in memory and then subtracted
from all future readings. Once the target is zeroed, subsequent readings show only the difference from the
original reading.
Calculating the Calibration of the Level Vials – Roll Axis
Note: It is very important to warm up the laser for at least 30 minutes before starting this procedure. It is
also very important to level both the Pitch and Roll axis level vials during this procedure. Failure to do
this makes it nearly impossible to calibrate the levels.
1. Level the laser.
Using the adjustment knobs, level the laser so both the pitch and roll levels are exactly level (see top
of Figure 4).
2. Zero the target in the Near Position.
Beginning with the Roll Axis, place a target on a point near to the laser. Mark this point so you can
always reposition the target at the same point. Zero the target according to the readout you are using.
3. Determine Far Reading 1.
Move the target to the Far Point, mark this point and record the target reading. This is Far Reading 1.
Measure the distance (D1) between the Near Point and the Far Points and write it down.
Note: It is recommended to repeat the measurements two or three times to check repeatability.
4. Determine Far Reading 2.
Rotate the entire laser unit 180 degrees. Re-level the laser using the adjustment knobs so both the
pitch and roll levels are exactly level. Return the target to the Near Position, ensuring that it is placed

11
in the exact position as before. Re-zero the target on this point. Move the target back to the Far
Position, again ensuring that it is positioned exactly as before. Record the target reading. This is Far
Reading 2.
Figure 7 -- Setup after rotating the laser 180 degrees
5. Calculate the Set Point – Roll Axis
Add Reading 1 and Reading 2 and divide by 2 (Set Point). Divide the Set Point by the D1 (distance
between the points). The result is the calibration of the level vial in units of in/ft or mm/m. To be
within specifications, the calibration result should be as follows:
Split Prism Vial Assembly: ≤ .00006 in/ft (0.005 mm/m)
Standard Levels: ≤.00012 in/ft (0.01 mm/m)
Example:
15 ft. (D1)
.000 (Near Reading)
.020 (Far Reading 1)
+ -.010 (Far Reading 2)
+.010 (Sum of the two readings)
+.010 / 2 = +.005 (Set Point)
Calibration = Set Point / D1
.005 / 15 = .0003 in/ft (out of spec)
If this value is out of the specification, then you will need to use the Set Point to bring it back into
specification. See the first step in the next section.

12
Setting the First Level Vial – Roll Axis
6. Tilt the laser to the Set Point
Move the target back to the Near Point to verify it still reads zero. If not, re-zero it. Then move the
target back to the Far Point and tilt the laser by adjusting the Roll Axis adjustment knob on the laser
base until the readout displays the calculated Set Point.
7. Adjust the level.
Locate the two recessed adjustment
screws for the Roll Axis level you are
adjusting (see Figure 8). Using the
wrench provided, adjust the level
assembly until the bubble is centered in
the window for the Standard Level Vials
or the two halves of the bubbles line up
for the Split Prism Level Vial (see Figure
4 and Figure 5). For example, to move
the bubble to the left, loosen the left
screw and tighten the right screw. When
the bubble is centered, tighten the left
screw until the bubble is stationary.
Check your work by repeating these
steps and ensuring that the level is
calibrated to within the specified
tolerances.
Note: Tighten the set screws just firmly
enough to hold the window assembly in place.
Over-tightening these screws may cause
damage.
Calculating the Calibration of the Levels Vials – Pitch Axis
1. Level the laser.
Rotate the entire laser unit 90° to calibrate the Pitch Axis level vial. Using the adjustment knobs, level
the laser so that both the pitch and roll levels are exactly level.
2. Zero the target in the Near Position.
Set the target on the same Near Position as before and re-zero it.
3. Determine Far Reading 1.
Move the target to the same Far Position as before and repeat Step 3 (Roll Axis) above.
4. Determine Far Reading 2.
Rotate the entire laser unit 180°. Re-level the laser using the adjustment knobs so both the pitch and
roll levels are exactly level. Return the target to the Near Position, ensuring that it is placed in the
exact position as before. Re-zero the target on this point. Move the target back to the Far Position,
again ensuring that it is positioned exactly as before. Record the target reading. This is Far Reading
2.
5. Calculate Level Calibration and the Set Point – Pitch Axis
Add Reading 1 and Reading 2 and divide by 2 (Set Point). Divide this Set Point by the D1 (distance
between points). The result is the calibration of the level vial in units of in/ft or mm/m. To be in
specification, the calibration result should be as follows:
Figure 8 – L-733 (top view) showing location of Precision Level Vials and
corresponding adjustment screws

13
Split Prism Vial Assembly: ≤ .00006 in/ft (0.005 mm/m)
Standard Levels: ≤ .00012 in /ft (0.01 mm/m)
Example:
15 ft. (D1)
.000 (Near Reading)
.035 (Far Reading 1)
+ .010 (Far Reading 2)
.045 (Sum of the two readings)
+.045 / 2 = +.0225 (Set Point)
Calibration = Set Point / D1
.0225 / 15 = .0015 inches/ft. (out of spec)
If this value is out of the specification, then you will need to use the Set Point to bring it back into
specification. See Step 6 below.
Setting the First Level Vial – Pitch Axis
6. Tilt the laser to the Set Point
Move the target back to the Near
Point to verify it still reads zero. If
not, re-zero it. Then move the target
back to the Far Point and tilt the
laser by adjusting the Pitch Axis
adjustment knob on the laser base
until the readout displays the
calculated Set Point.
7. Adjust the level.
Locate the two recessed adjustment
screws for the Pitch Axis level you
are adjusting). Using the wrench
provided, adjust the level assembly
until the bubble is centered in the
window for the Standard Level vials
or the two halves of the bubbles line
up for the Split Prism Level vial (see
Figure 4 and Figure 5). For
example, to move the bubble to the
left, loosen the left screw and
tighten the right screw. When the bubble is centered, tighten the left screw until the bubble is
stationary. Check your work by repeating these steps and ensuring that the level is calibrated to within
the specified tolerances.
Note: Tighten the set screws just firmly enough to hold the window assembly in place. Over-
tightening these screws may cause damage.
Checking the Levels for Accuracy
To check for accuracy, repeat the steps for setting the precision level vials. The Set Point should be the
same as the previous Set Point. If not, calculate a new set point and adjust as necessary.
Figure 9 – L-733 (top view) showing location of Precision Level Vials and
corresponding adjustment screws

14
Measurement Overview
In general, a laser is used for alignment by making it parallel to reference points and using a target to
measure deviations from those points. Reference points are points chosen on a surface or in a bore that
represent the starting point for which all other points on the surface or in a bore will be compared. For
bore, spindle and rotating shaft applications, two reference points are needed to establish a datum, or the
basis used for calculating and measuring. For surfaces, three reference points are needed to establish a
datum.
For continuously rotating laser applications, like machining centers and presses, three to five reference
points are needed, although Level to Earth Measurements are frequently used instead of reference points.
Laser buck-in refers to the adjustment of a laser plane or beam to be parallel to the reference points (a
table top, a surface plate, or a way surface).
Once the laser is "bucked in," any point within range of the laser device, typically up to 100 ft. (30.5 m),
can be measured for deviation in one axis for rotating laser applications. One of the principal advantages
of geometry lasers is that they provide live alignment data, which means a machine or part may be
aligned without moving or changing the laser's setup. In effect, the targets act as a live digital indicator of
the alignment. When the target reads zero, the point is aligned and the next point is measured.
Selecting Reference Points on Machine Tools
When using a laser system or any other alignment method, it is important to select reference points
carefully. Poor reference points, like those on the heavily worn portion of a machine bed where all the
work is performed, may mean extra time to bring the machine back into tolerance. In other words, it could
be the reference points that need alignment rather than the rest of the axis.
In metrology, it is recommended that some sort of data analysis be performed on a machine's axis before
proceeding to the alignment stage. This step may save countless hours when aligning a machine tool that
has only a couple of bad points. Typically, a least-squares, best-fit algorithm is applied to a set of data for
an individual axis. This algorithm calculates a line or a plane that best fits the data and will quickly show
any bad data points. The data can also be adjusted so the alignment for each point would bring it parallel
to the best-fit line or plane.
Selecting Reference Points on Process Mills
Conventional methods of roll alignment usually use floor benchmarks (monuments) at the side of the
machine as references. The L-742 and L-732 offer the versatility of using the benchmarks or of picking
up a reference roll, such as a cooch roll on paper mills. However, we strongly believe that using a
reference roll provides a more accurate reference and results in better alignments.
Benchmarks are usually set in a thin concrete floor, are rarely covered, and are routinely run over and
nicked. More importantly, they move with their slab of concrete and rarely hold their position relative to
the mill itself. Most floors in a typical plant have multiple slabs and are usually cracked throughout,
creating instability of the monuments. Unless checked every time they are used, the use of the benchmark
probably will result in significant alignment errors.

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Measurement Summary
The following section is a brief summary of how the laser is used to measure straightness, flatness,
squareness, levelness and parallelism. Note that if a machine is going to be aligned, rather than just
measured, it is important to put the laser on an instrument stand. If the laser is on the machine bed or
table, adjustments will likely move the laser and affect the setup.
Figure 10 – Measuring Straightness, Flatness and Squareness
Measuring Straightness
To measure (horizontal) straightness of a surface or machine axis, two reference points and one vertical
laser plane are needed.
1. Mount a target horizontally at the closest reference point to the laser and adjust the target so
that it detects the laser.
2. Zero the target and move it to the farthest reference point from the laser. Use the YAW
adjustment to produce the same reading for both reference points.
The laser is now parallel or “bucked in” to the reference points.
3. Place the target at intervals along the surface or machine axis.
Any deviations from zero are a measure of straightness relative to the reference points. If the target is
mounted so that its top is to the left of the laser plane, then a "+" reading means the measured point is
to the "left" of the reference points and a "-" reading means the point is to the right of the reference
points.

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Measuring Flatness
To measure flatness, a horizontal, continuously rotating laser plane is “bucked in” or adjusted so that it is
parallel to three reference points on a table, set of ways, or a surface.
1. Place all the targets on one reference point and adjust them up or down so they detect the laser
plane.
2. Zero the targets.
3. Reposition the targets so that one target sits on each reference point.
4. Using the PITCH and ROLL adjustments, adjust the laser scan plane until all three targets
produce the same value or zero, thus making the laser parallel to the reference points.
This may also be accomplished by using one target, zeroed on the closest reference point to the laser,
and moving it back and forth from the reference points until it produces a reading of zero at all three
points.
5. Move the target to user-specified points on the surface.
The resulting reading is a measure of the deviation from the reference point, helping to produce a
flatness profile. The measurement will show either a plus (+) or a minus (-) sign. A plus reading
indicates that the target is higher than the reference points and a minus reading means the target is
lower than the reference points.
Measuring Squareness
After bucking in the laser to the five reference points described in
Measuring Straightness and Measuring Flatness, (to determine the
straightness and flatness of the machine's axes) measuring
squareness is a simple process. To truly measure squareness, one
must compare the least-squares, best-fit line of the one axis to the
other axis. If this is not done, bad reference points or severely worn
ways might produce what looks like a squareness error, but in fact
is not. To facilitate this type of analysis, our software programs may
be used to automatically calculate the best-fit line.
To measure Y-to-Z squareness:
1. Lower the column/spindle to its lowest Z position and
position a target horizontally to pick up the vertical laser
plane that is perpendicular to the X-axis (parallel to the
Y-axis).
2. Zero the target and traverse (raise) the column along its axis.
The data produces a measurement of both the straightness of the Z-axis and the squareness of the Y-
axis to the Z-axis.
To measure Z-to-X squareness:
1. Position and zero the target to detect the vertical laser plane that is parallel to the X-axis.
2. Traverse the column upward.
The resulting data is a measure of the Z flatness and Z-to-X squareness.
To measure X-to-Y squareness:
1. Position and zero the target to detect the vertical laser plane that is parallel to the X-axis.
2. Traverse the table or column (whichever is moveable) along the Y-axis.
The result is a measure of both Y straightness and X-to-Y squareness.
Figure 11 – The X, Y and Z Axes