Machine Shop Uses Mastercam to Eliminate Extra Programming
Oldenburg Metal Tech, Inc., is a big presence in tiny Saukville, Wisconsin. This 25,000 square foot machine shop specializes in complex, progressive stamping dies as well as welding fixtures, production parts, and prototypes for anything from automotive steering brackets to dental trays.
Volumes can run in the hundreds or into the thousands for small production components. The stamping dies feature complex geometries with tight tolerances that are time-consuming to produce due to tooling or programming issues. To minimize time and costs, Oldenburg invested in 10 vertical machining centers, four turning centers—one with live tooling dedicated to production machining—and Mastercam to make programming easier and more functional.
CNC Programmer Vinny Decker said that most of the jobs have complex geometries with tolerances within 0.001” to 0.002” but can go within tenths of an inch when necessary. “We do so much hard milling here, that with some of the tighter tolerance or 3D work, the stamping box will be heat-treated, and I’ll need to perform a secondary hard mill operation to achieve certain tolerances, finishes, etc.,” he said. Decker relies on several software features to help him achieve these tolerances in less time.
Oldenburg recently machined 16 large, complex 3D stamping blocks measuring roughly 24” x 16” or so, and 4” to 5” thick. The entire top of the blocks featured 3D contours in small radiuses. According to Decker, it would have been impossible to machine them just a few years ago. The total process took about 20 hours per time block, including investigating the right toolpaths and cutter technology for hard milling.
Dynamic Motion technology allows the shop to push the machines to their speed limits. Through proprietary algorithms programmed into the software, the tool remains constantly engaged with the material, automatically sensing changes in geometries programmed into the high-speed toolpaths. “A lot of what we do is high speed area roughing with high speed mills. The high-speed waterline and raster finishing paths are done with carbide end mills and saw mills.” Dynamic milling is also used for deep with the machines removing material at a rate of 150” to 200” per minute.
The toolpaths have allowed Oldenburg to take on larger jobs. “When it comes to die building, we do dies that are double the size of what we were doing a couple years back. The blocks are much larger, requiring a lot more 3D contouring. A block that might have taken us 20 hours to machine before is taking us eight to 10 hours because the different types of toolpaths can efficiently cut down on time when machining certain features,” said Decker.
Verify provides Decker and the machinists the confidence to run the machines at high speeds without worrying about tool and part breakage, or damage to the machine. “I verify every program I write because there are days where I’m programming 30 to 40 parts per day,” said Decker. He “collision checks” parts where there are deep pockets or 3D contouring. The compare feature ensures that he didn’t accidentally hit something in the toolpath while the Accurate Zoom feature allows him to get an idea as to what the finish will look like. He uses stock models on bigger parts with a lot of toolpaths if he doesn’t want to verify an entire part.
Model Prep is Decker’s favorite function. “A couple of years ago, I might not have been able to close up a surface or fill in holes on a 3D surface,” he recalled. “I would have to go to our designers and ask them to create a separate model without the holes in order to run 3D paths on it.” Now he can extend 3D surfaces, move them up and down to add more clearance or add more stock if necessary. By eliminating the need to create a separate surface model, he saves anywhere from five seconds to an hour in programming time.
“The best part of the software for me is the Model Prep feature for sure. Just by adding those model prep features in Mastercam, it basically eliminated a step in my process because I no longer need new designs to suppress or change features on a 3D model.”
You can read more about Oldenburg’s projects in this article in Fabricating & Metalworking online: Using Advanced CAD/CAM to Optimize Machining of Complex, Progressive Stamping Dies.