Workholding Fixtures Save Over 4,500 Hours of Labor Annually

In February 2023, New Dimensions Precision Machining was in search of a solution to help streamline manufacturing of hydraulic control valves. The company was producing thousands of high-volume valves annually and planned to integrate a FANUC robot for loading and unloading the cast-iron valves. The team of engineers at All World Machinery Supply that works with the Arrow workholding fixture product line developed a custom solution that was just what the customer needed.

A Need for Production

When All World was approached, New Dimensions had already contracted CNC Solutions, located in Johnson Creek, Wisconsin, for a customized robotic solution.

New Dimensions services customers in the hydraulics industry and began adding fully robotically loaded equipment in 2022 in response to labor shortages and labor cost struggles. The goal was to maintain continuous operation of the cell, running 24/7 with minimal human involvement, limited to inspection and material handling tasks, said New Dimensions Precision Machining director of business development Martin Halwix.

The company sought a hydraulic solution to maintain consistency and repeatability. Typically, Arrow workholding fixtures connect to All World’s ClampMax hydraulic power systems. Equipped with highly efficient Daikin pumps with inverter control, the power units ensure optimal performance, according to All World project manager Scott Tilton.

A Demand for Robotic Collaboration

New Dimensions’ cells, combining robotics and hydraulics solutions, are considered a model application for growing automation needs, said Aaron Zuehlke, the company’s CNC Solutions applications engineering manager.

The company’s FANUC robotics system 10DER TS-X consists of an 80% pre-programmed standalone solution with 20% customizability, which caters to manufacturers like New Dimensions who machine similar-sized parts with minimal tooling changes and multiple part numbers. Operators can easily switch to a different part number in minutes by simply changing the part cutout insert found on its shelves and adjusting the grippers.

After machining operations are completed, the robot moves the parts to an engraver for product information stamping then returns them back to their original nest. When full, an operator pulls finished parts out of the nest and reloads with raw material.

To keep the mostly automated process running smoothly, a workholding solution must securely hold and accurately position the part during machining. The fixture must allow for easy insertion of the part without getting stuck, while also ensuring it remains in place when the fixture rotates.

Unlike humans, robots are programmed to move to repeatable positions, but they lack the dexterity needed to maneuver the part. While traditional fixtures rely on human operators for proper seating, centering or pushing of the part, the New Dimensions' project required a workholding fixture capable of moving the part to different datums via in-process clamp control.

Up to the Task

All World engineers rose to the challenge and began designing a versatile workholding fixture to securely hold hydraulic pump blocks for New Dimensions’ Makino A51NX 4-axis horizontal machining center shortly after receiving the order in late 2023. The design enables the machining of four parts in each of two different operations.

“Enabling machining through fixture clearance windows is a high-volume and high-efficiency solution. It reduces product handling, leading to improved tolerance control and dimensional accuracy,” Tilton said.

During the first step, operation (op) 10, the part is machined on the front face and also through a window on the opposite side.

During op 20, the part is located by features previously machined in op 10. Additional faces are then milled at the 90° and 270° B-axis positions.

At the end of the cycle, a robot removes complete parts, shifts op 10 parts to the op 20 stations on top, and loads four raw blanks into the op 10 spaces.

The robot is responsible for rotating the fixture and turning it in 90-degree increments at the load station.

Refining the Plan

During the review process, engineers had to consider tool reach, fixture weight, robot access and other space requirements.

“It was a challenge to work with the competing constraints to get four parts up and keep everything within the weight limit and travel limits of the machine,” All World engineering manager Steve Hagedorn said.

Engineers designed the unit with all internal hydraulic passages and no external tubing, resulting in a clean appearance with ample tool holder clearance and no chip accumulation. Additionally, the fixture comprises live hydraulics and incorporates air gap part seat detection for accurate part loading.

As part of the op 20 process, the workholding fixture checks the air gap within the appropriate tolerance range to ensure proper seating without any debris or incorrect placement. If the fixture detects any discrepancies, it promptly flags them for correction.

Halwix commended All World engineers for suggesting air seat detection, which wasn’t initially included in the automation package. By communicating with CNC Solutions from the start, engineers incorporated the feature early on, preventing additional costs at the project’s end.

Having such close collaboration between CNC Solutions and the All World Machinery Supply team, Halwix said, helped prevent the pitfalls of earlier automation projects New Dimensions experienced when fixturing and robotic suppliers were working separately until integration.

“There are bugs to work through and redesign, rework and delays. Every robotics integrator has a little bit different type of hydraulic pump and sequencing capability, and every fixture designer has different things in mind,” Halwix said. “Having the fixturing and robotics all planned together from the start made this particular project go a lot smoother.”

A total of four customized fixtures were shipped after a series of reviews with CNC Solutions and New Dimensions. Get a closer look at the custom-built Arrow workholding fixture in this video.

Around-the-Clock Automation

The major benefit of automation, Halwix said, is 24/7 operation and being able to staff difficult to fill shifts.

At the start of the shift, one person can dedicate an hour to prepping the robot, then transition to loading other machines. This approach replaces spending the entire 10-hour shift on one machine. With automation, instead of four machines requiring 100 hours of labor per week with 10-hour shifts, they now only require two hours of labor.

“In a given week, we are saving almost 90 hours of labor,” Halwix said.

Following the success with automation at the Union, Illinois, facility, New Dimensions is looking into automation for their facilities in Schaumburg, Illinois, and Greenwood, Arkansas.

A Legacy of Precision

With a history of 60 years refining workholding solutions and with over 100 years of combined experience in fixture design, the team that handles Arrow workholding fixtures at All World prides itself on engineering reliable, durable fixtures with precision.

“Your fixture will hold parts securely and clamp them repeatedly, in the same place each and every time,” Hagedorn said.

Arrow’s hydraulic, mechanical and pneumatic fixtures are engineered to last 10-20 years. Hagedorn said the 32-employee team prioritizes producing the best fixtures possible for its customers, not taking shortcuts to increase profits.

“We do not skimp on quality materials or construction methods and buy the absolute best components. Workpiece contact surfaces are hardened tool steel or carbide, and other steel components are black oxide coated for long life and corrosion resistance,” Hagedorn said.

The team purposely designs each fixture to minimize the number of operations, resulting in reduced handling and idle spindle time. This contributes to faster parts production. Additionally, there is careful consideration given to maintainability. Fixtures incorporate easily accessible fasteners and the use of off-the-shelf items whenever feasible.

“We are proud of designing fixtures that are simple for the operator to use correctly and free of sharp edges and pinch points,” Hagedorn said. “Our customers recognize that Arrow workholding fixtures offer them reliability and maintainability and make an excellent investment.”