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L-742 Roll Alignment System

Blown Film Line Application


High-Accuracy Roll Alignment LaserThe L-742 Ultra-Precision Dual Scan® Laser offers 2 automatically rotating laser planes. It has been designed specifically for roll alignment applications. It is a very affordable yet powerful tool to not only MEASURE but also FIX roll misalignment on almost any kind of process mill, all in a fraction of the time needed with conventional methods.

A blown-film line requires 2 different alignments. The first is to align the vertical die centerline to a set of nip rolls, frequently 3 stories or so higher than the die. Traditional methods of using a plumb bob are difficult to set up and are not very accurate. Misalignment results in poor product quality and lots of downtime trying to fix it.

The second alignment is the parallelism of the nip rolls to the take-up rolls. This is an extremely difficult task as the nip rolls are frequently 3 stories higher than the take-up rolls. If the rolls are not aligned properly, the product will start to wrinkle and "walk" to one side of the rolls, seriously impacting product quality.

L-700 Laser Alingment System
L-700 Spindle Alingment
System, Shown with L-700
Spindle Laser, T0261A Target,
Spindle8 Software, A-807
Calibration Fixture and
Laptop Camputer

L-700 Ideal Solution to Die-to-Nip-Roll Alignment

The L-700 Laser Alignment System is an ideal system to align the nip rolls to the die. Using the rear-mounted .500" mounting stud and our NORMIN method, the L-700 can easily be fixtured into the center of the die, projecting the center up to 100 feet (30.5 meters). To see if the nip roll is centered over the die, a simple fixture is used to hold a 2-axis target. Each end of the roll is then measured to determine how centered it is to the die. The system has an accuracy of +/-.001" (.03 mm) in 100 feet.

L-742 Significantly Eases Roll Parallelism Checks

The L-742 significantly simplifies nip-to-take-up roll alignment. With 2 automatically rotating laser planes, each with 100 feet (30.5 meters) of range in radius, roll alignment to +/- .002" (.06 mm) in 100 feet becomes not only feasible, but easily attainable. In fact, the L-742 is so easy to use it usually only requires one technician to operate it.

More Accurate Alignment Increases Material Flow and Quality

With poor alignment, most roll-type machines, whether a film line or paper machine, will produce a product that has wrinkles and other quality problems. The material will also want to wander or "walk" to one side of the roll or the other. This means a lot of downtime and tons scrapped products. Frequently, the only methods available are optics or using trial and error with tram bars, both of which are very time-consuming and costly.

The L-742 Roll Alignment System, by contrast, is so accurate and easy to use that you can get the alignment right the first time, saving enormous costs in reduced downtime, scrapped product and quality problems. In fact, most machines that can handle it can run at faster speeds after laser alignment. This increased productivity will pay for the laser in a matter months, in some cases.

Read 9 PDA Software - Roll Alignment Tab High Accuracy Reduces Optics' Guesswork

Hamar Laser's L-742 Roll Alignment System is accurate to +/-.002" (.06 mm) in 200 feet (61 meters) under good atmospheric conditions. This accuracy turns the alignment process from an art using optics to a science using lasers. Optics are considered an art because each operator "sees" the readings differently and essentially has to make an educated guess as to the correct number. In fact, it is rare that any 2 optics operators will get the same numbers. With the L-742, this guesswork is essentially eliminated because the target electronics determine the alignment reading. And it is very repeatable from one operator to the next!

Factory-Built Benchmark Fixturing

The L-742 Roll Alignment System comes with fixtures to pick up floor benchmarks for aligning the laser to the machine's centerline. The L-742 also has the flexibility to easily use the reference roll to set up temporary offset centerlines. In fact, this is our preferred method of referencing the machine's centerline, as benchmarks are frequently in not much better shape than the floor they sit in. Cracks in the floor can seriously affect the position of the benchmarks and often result in poor alignments.

Laser Planes Have 200-Foot Range Vertically and Horizontally

One of the most powerful features of the L-742 is the automatically rotating laser plane with 100-foot (30.5 meters) range in radius. That means rolls, at almost any elevation, can be measured simultaneously without having to move the laser vertically. This also allows the laser to be moved to more sections without having to change the location of the reference targets.

Competitive Systems Use 10-Year Old Technology

Our competitors' roll alignment systems use point-and-shoot laser technology, along with remote beam-bending devices that are difficult to set up and relocate. We abandoned that laser technology 10 years ago with the introduction of our multi-plane, continuously rotating lasers. Not only is this point-and-shoot technology difficult to set up, it also requires extra manpower and about 50% more time.

Less Manpower Needed for Alignments

The L-742 Roll Alignment System reduces the alignment-team manpower. Wireless targets and automatically rotating laser planes make setting up the laser at each machine section easier. Our laser systems usually require only one operator. The wireless readout displays both targets simultaneously, allowing the user to quickly reference the benchmarks. Traditional optics usually require at least one man holding a reference target in both reference locations.

No Need for Optic's Time-Consuming Recalibration after Plumb Measurements

Unlike optics that usually require recalibration of the levels each time plumb is checked, the L-742 can simultaneously check level and plumb from a single setup. The levels usually only require one calibration at the start of the job, and if the laser is not taken off the base, level calibration is only required once a month.

zigbee wirelessWireless Targets and Readout Speeds Setup

With Hamar's new line of wireless targets (A-1519-2.4ZB & A-1520-2.4ZB or A-1532 & A-1533) there is no need to string long extension cords to reference targets. The targets have up to a 3" (76 mm) measuring range and can be used up to 100 feet (30.5 meters) from the laser.

The 1532/1533 targets have built-in readouts and .001" (0.013 mm) resolution. The A-1519-2.4ZB and A-1520-2.4ZB, have up to a 1" measuring range, a resolution as low as 0.00001" (0.00025 mm) and can be used up to 100 feet (30.5 meters) from the readout. The R-1355-2.4ZB Readout uses a PDA & color software to display up to five targets simultaneously. Other features like electronic zeroing and target averaging help to speed setup.

Application note
L-740 and L-730 Datasheet
How it Works
L-742 - How its works


  • Two continuously rotating laser planes with operational range of 100’ (30.5 m) in radius
  • Laser planes flat to .00003”/ft (0.0025 mm/m)
  • Using a reference roll, the measuring laser plane is parallel to roll datum to .000045 in/ft (0.0038 mm/m) at any location along the machine
  • Split-Prism levels accurate to .00006 in/ft (0.005 mm/m)
  • A-1519-2.4ZB Single-Axis Wireless Target with 1.3” (33 mm) PSD and .00002” (0.0005 mm) resolution
  • R-1355-2.4ZB Wireless PDA displays up to 5 targets simultaneously
  • Factory-built benchmark reference fixtures for easy laser transfers and referencing floor benchmarks
  • L-106 X-Y Tripod Translation Slide to speed up laser transfers and target setup
  • Typical setup time 15 minutes or less
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