Commercial Tool & Die injection molds, typically made from high-hardened tool steel, require rigid milling equipment.

Founded in 1953, Commercial Tool Group (CTG) has grown from a small mold shop into a major supplier of injection and compression molds, fixtures, automated equipment, and robotic handling devices. The company provides turnkey solutions for manufacturers of various plastic and composite parts in the automotive, heavy truck, recreational vehicle (RV), and appliance industries.

When the company’s Commercial Tool & Die (CTD) division ran into challenges that required new milling equipment, engineers quickly found that even the best machines from the best producers failed to fit their exact needs. Zimmermann’s FX40 Compact portal milling machine was very close, but a few critical elements were missing.

“We usually get pushback from machine builders when we request design changes, but the Zimmermann team was very responsive and flexible,” says Darin Hall, plant manager at CTG. The company asked Zimmermann to modify probes, extend the Z-axis, increase tool-change capability, increase C-axis rotation for 5-axis programs, fine tune gear boxes and motors, and redesign the tool changer.

Commercial Tool Group supplies moldmaking, fixturing, automation equipment, and robotic handling mechanisms.

Zimmermann Inc. President Cornelius Kiesel says, “Our company had substantial experience in Germany with moldmakers using the FZ40c, a machine designed specifically for the moldmaking market, but we knew the machine’s capabilities could be expanded to meet the needs at CTD. Our engineering department and application specialists got to work and came up with a solution to suit the requirements.”

Engineers changed mechanical and electrical designs on the machine and modified software on the machine’s Heidenhain CNC. The machine tool maker also devised a lease-to-buy agreement, enabling CTD to use the machine during runout on modifications. The results were documented and reported back to the builder.

Extending Z-axis software and fine tuning the Z- and C-axis movements improve surface finish for Commercial Tool & Die (CTD), allowing diamond buffing on the machine and eliminating hand polishing.

Machine benefits

“We saw great potential in the Zimmermann machine after encountering it at an IMTS event in Chicago,” Hall says. “The open design, overhead gantry, extremely solid base, and rigidity of the entire machine were appealing. Its overall weight was twice that of the competing machines we examined. We knew the accuracy would match our needs, as the A- and C-axis clamping forces of Zimmermann’s VH60 milling head would allow us to take full advantage of HSK100 tool torque and horsepower ranges.”

The rigidity of the Zimmermann machine provides the accuracy needed for injection molds for optics and lenses and surface quality required for automotive Class A parts. CTD’s machining operations are monitored but unattended, so the reliability and repeatability of the Zimmermann machine had high appeal.

“Zimmermann machine technology has improved our process with at least a 10% reduction in cycle times with no compromise in surface quality,” Hall says. “It enables us to use very aggressive machining strategies on our molds, using HSK100 spindle technology. This allows CTD to machine parts much faster than with other equipment, with better quality.”

The FZ40 Compact transmits data from the CNC to an Epicor enterprise resource planning (ERP) system that tracks performance to plan work schedules, compare shift performance, and assess overall equipment effectiveness (OEE).

CTD engineers required significant modifications to Zimmermann’s FZ40 compact 5-axis portal milling machine to suit its needs, including upgrading probes, upgrading the laser tracker, redesigning the tool changer for larger tools, and extending the Z-axis.

Software, equipment

CTD uses Powermill CAM software with CAM-to-machine tool integration, so employees can inspect parts performed before removing workpieces from the machine, an important feature for the large mold sections typically produced in this machine. CTD also uses Zeiss CMM and Creaform laser 3D inspection technology.

Using motion control programming on the CNC, CTD engineers fine tuned individual Z- and C-axis movements to maximize surface finish quality, allowing CTD to eliminate most hand polishing operations.

Many of the machine modifications designed into the Zimmermann FZ40 Compact for CTD will become standard options on the machine in the future. CTD will soon acquire more equipment from Zimmermann, as two more Zimmermann machines for the company are currently in the build stage.

Commercial Tool Group

Zimmermann USA