Alignment Measurements in 1/10th the Time


UNISIG, a manufacturer of deep hole drilling machines used to schedule 1 to 2 days for measurement and quality checks of the machinery it produces. With an API Radian laser tracker, it now accomplishes the same task in 1 to 2 hours. The Radian also travels with UNISIG technicians to customer sites for machine delivery and setup.

To drill a hole in plywood for a home improvement project, feel free to use a drill from a hardware store. To drill a hole through nickel superalloy in the manufacture of aircraft landing gear, you need something far stronger and more precise. This is what UNISIG provides to the aerospace, energy and firearm industries, as well as any other manufacturer for whom hole diameter and tube straightness must meet tolerances of just a few microns. With such high demands for precision and reliability, UNISIG needs its own manufacturing equipment to be as perfect as its products. To achieve that, it turns to laser trackers from Automated Precision Inc. to help build their machines and check their product quality.

UNSIG has two API trackers – a Radian and a Tracker 3 – in its manufacturing facility, located just north of Milwaukee. A division of Entrust Manufacturing Technologies, UNISIG offers a full range of deep-hole drilling machine lines, with several configurations within each line. These machines can drill deep holes for aircraft manufacturing, oil exploration equipment, mold manufacturers, and even gun barrels. UNISIG makes machines that range from compact to machines over 100 feet long. UNISIG also makes massive 7-axis CNC machines capable of handling 25-ton work pieces.

Tight Tolerances or Disastrous Consequences

To build machines this size, UNISIG needed a measurement system that could accurately measure and map 3D points over such a large area. UNISIG technicians use the API Radian primarily to measure straightness and alignment of their machinery, to in turn allow customers to produce extremely straight workpieces.

A “deep hole” is considered one that has a ratio of the depth to diameter as 20:1 or greater. A typical twist-type drill found in a machine shop can only handle ratios of 10:1. UNISIG machines are able to accurately drill holes greater than 200:1, while meeting strict tolerances required by customers.

As API’s premier laser tracker, the Radian is capable of measurements using either Absolute Distance Measurement (ADM) technology, or an interferometer, which is a Tier 1 “traceable” measurement device that offers the greatest accuracy and assurance. Using the built-in interferometer, the Radian can accurately measure points within 7 microns, or 0.0003 inches, thus ensuring that the alignment and straightness of the machinery will meet or exceed UNISIG’s rigid specifications.

From 1 to 2 Days to 1 to 2 Hours

UNISIG first acquired a Tracker, which was API’s highest accuracy laser at the time of purchase. It later bought the Radian after it was released in 2011.The versatility of the API laser, with its ability to run with all major metrology software providers, be mounted in hard-to-reach places or at an angle, and even compensate machinery were important factors in UNISIG’s decision to purchase and API, said Bob Bequest, the service manager for UNISIG.

The Radian is often used to measure 40-foot rails to within 1 to 2 thousandths of an inch. Technicians need to obtain the straightness, make sure they are parallel with an adjoining rail, as well as obtain the angular distance and squareness of the entire component.

Prior to acquiring an API tracker, UNISIG technicians used an older laser alignment system that only measured in straight lines, with no three-dimensional picture and an array of other precision tools.

“We had to be creative on how we shot things, using indicators and straight edges,” said Tony Curro, a machine builder for UNISIG who has been using API trackers for more than a year.

These methods were not only less reliable, but took far longer to setup and measure. With the introduction of API trackers, the time UNISIG technicians took to take a straightness measurement of a rail decreased from 1 to 2 days to 1 to 2 hours.

Active Target

UNISIG was able to speed up its process even more with the acquisition of an Active Target from API. This motorized target locks onto any API laser tracker and automatically positions itself so it will never lose the beam. The Active Target can be attached to its machine spindles or other moving parts to continuously measure the machine’s movement.

Within the Active Target, a spherical mounted reflector (SMR) nest sits in the spindle of the machine. As it spins, it measures the arches. From this movement tracked by the Radian, Curro can obtain values for the bore and the center point of the bore within one-thousandth of an inch.

“As we’re building, we’re using the laser to make adjustments,” Curro said. “(With the Active Target) we can easily shoot that point again.”

And it Travels

One of the few machine exporters left in the U.S., UNISIG does all its manufacturing in-house, but ships machinery all over the world. UNISIG builds every drilling machine in its facility, then disassembles it for shipping. And the laser tracker often goes with it.

Technicians will often take the Tracker 3 or Radian to customer sites, where it is used to ensure proper installation of the machinery. The Tracker 3 recently returned from a trip to India and Singapore. When it arrives at the customer site, the API tracker can take into account the differences at the new facility, whether it is a softer foundation or even more humid environment.

“The portability makes it very user friendly,” Bequest said.

Making Good Machines Even Better

As UNISIG continues to produce increasingly complex machinery with higher demands, Bequest finds new ways to make the Radian help them do their job. One new use for the tracker is helping UNISIG get more life out of an aging machine. The machine has a slight bow in the movement of one on of its axes, but by using the Radian to map out a perfect square, technicians can still use the machine to cut material. Bequest said he is interested in investigating API’s Volumetric Error Compensation solution, which uses the Active Target and Radian to actively compensate for slight machine skewing.

Almost every manufacturing sector has a need for deep hole drilling applications in some part of its process. As UNISIG finds new opportunities in demanding industries around the world, API technology will help them ensure that they get it right.

UNISIG was founded in 1981 to provide deep hole drilling machines and related services to the US market. In 1995, UNISIG was acquired by Entrust Manufacturing Technologies, Inc. and relocated near Milwaukee, Wisconsin. UNISIG understands deep hole drilling and is experienced in the range of applications and holes brought to us by our customers. An experienced team including engineers, technicians, and other staff work together to provide high-precision deep hole drilling machines and equipment. UNISIG machines are proudly engineered and manufactured in the USA, and are supported by a carefully chosen, reliable group of local suppliers.