Take Back Time: 5-Axis Machining

Cavalier Tool & Manufacturing’s investment in new capabilities pays off with benefits in cost cutting and increased productivity.

When times are tough, there’s only one way for manufacturers to get ahead: be aggressive and forward thinking in their business planning and investments. Cavalier Tool & Manufacturing Ltd. took this approach and has reaped the rewards ever since.

Courtesy of All images: Makino

The Makino a92’s 10,000-rpm spindle, 1,969-ipm rapid feed rate and 0.4G acceleration/deceleration rate offer Cavalier Tool nearly three times the productivity compared to the moldmaker’s previous technology.

Established in 1975, Cavalier Tool, Windsor, Ontario, is a global manufacturer of mid-sized to large plastic injection molds for the automotive, commercial, recreational, medical and aerospace industries. It specializes in tooling for injection molding applications that use materials with high glass filler content, including fans, shrouds, radiator intakes, lighting tools, door carrier plates and door panels. The high glass content enhances stiffness, noted Brian Bendig, company president. Because the molding material is abrasive, the tooling is typically made of H-13 and sometimes S-7 tool steels.

“It’s important to know the capabilities you’re strong at and those where you could use some improvement,” Bendig said. “For the longest time, hardened material machining wasn’t our strong suit, and as such we relied heavily on outsourcing. However, once the economy took a turn for the worse, we decided it was time to regain control by investing in hard milling capabilities.”

Hard Milling, Easy Choice

Cavalier Tool was previously outsourcing machining of tool steel hardened to 48 to 52 HRC to a shop with a Makino A100 horizontal machining center, and Bendig was impressed with the machine’s speed, accuracy and finishing capability. So when it came time to reevaluate the company’s machining capabilities to recapture the hard milling work it was outsourcing, Bendig eyed Makino’s selection of HMCs.

“We had a lot of work coming through and had been researching machines for a couple of months,” Bendig said. He noted that the company has been happy with the results of its Makino SNC 86 graphite electrode mill. “Another reason we wanted a Makino was longevity and reliability. We knew a Makino HMC would be able to support our business well into the future. Our SNC 86 has been on the floor for 17 years, and it’s still very accurate and reliable.”

In June 2010, Bendig purchased a Makino a92 HMC based on its similar characteristics to the A100. The a92’s 10,000-rpm spindle, 1,969-ipm rapid feed rate and 0.4G acceleration/deceleration rate enhance productivity when producing large parts, according to Bendig. Its rigid construction provides positioning tolerances as tight as ±0.00010 “, with ±0.00006 ” repeatability.

The machine has a 31 “×39 ” pallet and X-, Y- and Z-axis travels of 59 “, 49 ” and 53 “, respectively, to handle workpieces up to 59 ” in diameter and height and weighing up to 6,600 lbs. Its automatic pallet changer switches a pallet in 46 seconds, achieving spindle runtime of 92 to 96 percent on a 24/7 basis.

A Welcomed Addition

After the a92 arrived on the shop floor, Cavalier Tool saw an immediate impact because the machine enables quick setups. “A lot of times, the orientation of the glass in the molding process is an unknown during tool production,” Bendig said. “As a result, we have to be prepared to handle any engineering changes from the OEM that occur during our production process. This makes it critical for us to be able to setup and tear down parts as quickly as possible without disrupting our overall workflow.”

Brian Bendig, Cavalier Tool president, with his a92 horizontal machining center.

The a92’s automatic pallet changer and a rear-clamping fixture coordinate system enable the moldmaker to set up several parts on a tombstone without interrupting the current machining processes or losing positioning accuracy. The rotary B-axis table increases flexibility much like that of a 5-axis machining center but without the inherent reduction in accuracy, according to Bendig.

He added that because it’s difficult to predict the “warp and windage” of molded parts, Cavalier Tool often needs to put the mold back on the a92 several times to recut it and having two pallets enables a mold to be prepared on one pallet while the other pallet is in the machine. When a mold is ready for recutting, which usually takes an hour or two, that pallet is positioned in the machine and, after recutting is completed, the pallet with the original workpiece is swung into place. “It’s difficult to predict what shape the final molded part will take,” Bendig said. “We can get it very close but often need to tweak the mold 1mm or 2mm—sometimes as little as 0.2mm. Sometimes we cut the tool ‘wrong’ to make the part right.”

Every mold tool coming out of the a92 is pretapped, chamfered, engraved and with machined finishes that require little to no manual labor.

Cavalier specializes in applications with high glass filler content, including fans, shrouds, radiator intakes, door carrier plates, door panels and lighting tools, such as this one for an automotive head lamp.

Mike McNaughton, the shop’s machining supervisor, said: “The combination of programmable through-spindle coolant technology, 92-capacity automatic tool changer and B-axis rotary table enables us to perform several types of operations with fewer setups. This configuration allows us to do drilling, boring, thread milling, tapping, 2-D and 3-D machining without the operator ever touching the part. With jobs we’ve transferred to the a92, we’re typically seeing a 50 percent reduction in the number of setups and up to three times the productivity of previous processing techniques.”

The shop also tracks spindle utilization through “Pulse” machine monitoring software from Lemoine Multinational Technologies Inc. “All of our machines are monitored day in and day out through our Pulse monitor for performance tracking,” Bendig said.

The software gathers idle times, feed rates, component name, operation type, operation length and other information and organizes the data in daily, weekly or monthly reports. These reports indicate that spindle uptime for the a92 is frequently in the 90 percent range.