The Center of Automation
Macro pallet-mounted gage balls reduce overall costs in electrode machining/manufacturing and reduce leadtime by 25 percent.
JK Molds Inc. (Upland, CA)—a manufacturer of high-volume, close-tolerance plastic injection molds specializing in the medical industry but also serving the home appliance, packaging, telecommunications, consumer products, electronics and healthcare industries—has customers ranging from custom part design firms to Fortune 500 companies at a global level. In business for more than 30 years, this 35-man shop found it had to rethink its strategy when faced with foreign competition, and the answer came in the form of an automation/gage balls combination that ultimately resulted in 25 percent leadtime reductions.
“The global market has been a challenge for us,” acknowledges JK Molds Managing Partner Jason Van Noy. “So, we decided we needed to automate to compete.” Over the years, the company had been investing in the latest equipment, but found it needed more leverage to ensure its long-term survival. Enter Len Graham Consulting (Cave Creek, AZ), which specializes in automated mold manufacturing. The company recently developed Model ADP-MI (pronounced “adapt me”) precision gage balls—designed to work in conjunction with System 3R USA, Inc. (Totowa, NJ) and Erowa Technology, Inc. (Chicago, IL) pallet technology—to reduce setup times and eliminate dimensional inconsistency on angles (including compound angles) and radial forms.
How They Work
Model ADP-MI precision gage balls are hardened, stainless steel, macro-pallet-mounted gage balls recently introduced by Len Graham Consulting to reduce overall machining costs in the machining/manufacturing process of electrodes and components. The balls incorporate the System 3R macro and Erowa 50 series pallets (See Figure 1).
According to JK Molds Vice President Patrick Elliott, consistently measuring dimensions with tight tolerance windows is not a problem with this methodology. Len Graham of Len Graham Consulting elaborates, “The gage balls are manufactured and individually certified to repeat to within +/- .0001 of center and also are within .0001 of a certified height from the resting pad of the pallet they are mounted on to the top of the ball. They allow the user to associate design, programming, machining and inspection to one common reference datum for all of these machining/manufacturing-related disciplines.”
The customary method of engineering gage ball dimensions—either from multiple sides of a component or from a gage ball reference somewhere off center of a component and perhaps even requiring machining/mounting the gage ball into the component—is outdated for palletized electrodes and components, Graham continues, as is relying on subjective microscopes/optical comparators for high-tolerance measurements. “The gage balls are set dead center of the pallet and at a repeatable height to within +/- .0001—making both symmetrical and non-symmetrical dimensions on palletized workpieces very easy to measure/achieve and consistent for both CMM and surface plate manual methods of checking the dimensions,” he explains.
Graham recommends generating a 3-D model of the part being machined on the pallet with the gage ball superimposed within the unit so the dimensions generated on the electrode/component design can be automatically related to programming, machining and inspection throughout the manufacturing process. Furthermore, programming and inspection also can be associated to the same model in the same fashion.
Van Noy notes that JK Molds’ use of the gage balls allowed the shop to achieve a global zero/global datum point between all setups in the shop, reducing setup time. He adds that since his shop’s automation is centered around System 3R, it made sense to start using the gage balls rather than develop its own system. “We were looking for a global data point so that all dimensions and tolerances are referencing the same point in the manufacturing process,” Van Noy notes. “The gage balls have reduced the setup time and checking time, and met our goals of having our machines running as long as possible.”
“It also helps us with our overall efficiency and communicating information from engineering to the shop floor,” Elliott states. “There are no more questions—when they set up the machine, they know we are going from the center of the gage ball and it’s easier to verify all the numbers. You don’t have to do any calculations—subtract this number from this datum and then check it with some other calculations or build some complicated stacks to check numbers—you just go from the same datum every time. It’s reduced the amount of time needed to calculate stack-ups before machining. Now we are using the global zero point on all of our inspection and that’s reduced that time significantly.”
Fortunately JK Molds’ employees were up to speed with the new technology within several months’ time, which Van Noy attributes to his employees exceptional math and conceptual skills they already pos-sessed. Initially, the company held several meetings to discuss the global zero point and to make sure all engineering drawings thereafter would reflect that datum.
Elliott adds that the combination of automation and gage balls has really made a difference in getting work done better, faster and smarter. “Just investing in automation doesn’t fix anything,” he cautions. “You have to rethink the way you are doing things from the beginning all the way through the end—looking at every process in the shop. When you make the decision to go with this system, you have to be ready to change your entire mold design and build process. It’s a lot more planning upfront and a lot more visualizing the entire process of how a job is going to run through the shop. If you aren’t committed to change, you won’t continue to be successful.”
What’s in a Name
Len Graham, president of Cave Creek, AZ-based Len Graham Consulting, explains how the company came up with the name Model ADP-MI for its precision gage balls.
Associating: When designing, programming, machining and inspection personnel are all using the same common reference data point working in their disciplines, the entire manufacturing process will be more consistent and can be greatly streamlined.
Designing: Beginning with design, palletized components to be machined using the Model ADP-MI precision gage balls would ideally be designed with it superimposed and associated to the pallet-mounted components. Any required dimensions would be listed from the surface to be cut on the component to the radial surface of the precision gage ball—regardless of whether that surface to be machined is planar, angular or three-dimensionally-radial in nature.
For example, take the irregular radial surface. There is always one point on any radial surface being machined, that when taken perpendicular to the centerline of the gage ball, will register a hard number at its low (concave) or high (convex) point and be easily checked with a CMM, or on a surface plate with a compound sine, to the surface of the precision gage ball. Remember, since the model controls the shape, that one point is all that is needed to accurately set its position in most cases.
Programming: Once the customer’s part model is generated and the components/inserts are defined, electrodes can be immediately and concurrently designed/programmed with the components on their pallets and generated, with machine programming referenced to the precision gage balls.
Manufacturing: All components to be machined that are mounted on pallets and programmed to the precision gage ball can be machined in a variety of CNC machines, as long as they are pallet- receiver equipped. After machining, components can be verified to file dimensions generated in reference to the gage ball.
Inspection: So far, everyone in the design, programming and machining disciplines will have used the same ADP-MI referenced dimensions in their processes. It is no time to change now. Inspection will follow suit in the final inspection/certification process using the same dimensions in the same fashion as designers set up for programmers and machining disciplines. If any discrepancies occur, it is far easier to trace the cause of the issue using this method, than it has been historically, when various shop disciplines may choose to use different, personally preferred methods along the way.
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