XL Machine was a Top Shops winning company in 2017. Plus, General Manager Chris Orlowski was part of a panel discussion with representatives from the other winning shops that year at our inaugural Top Shops Conference in Indianapolis.
In checking back with him a few months ago, I learned about a neat robotic cell the Three Rivers, Michigan, shop had recently added to machine three- and four-blade cast propellers (a family of 20 part numbers) for outboard boat engines. I mentioned that holding such contoured parts for five-axis machining had to be tricky. In fact, that was the most challenging part of the project, he said.
That, my friends, is a story hook, so I scheduled a visit to learn more.
Cell Structure
Founded in 1976, XL Machine (now part of the Burke Porter Group) began as a prototype machining company. It still does prototype work today, but pairs that with production machining capability. The shop serves various customers in markets such as automotive, heavy industry, entertainment and marine.
At first, the customer with the propeller job turned each part’s hub in house. XL Machine would then mill either side of the contoured blades on two stand-alone three-axis VMCs and a stand-alone HMC that blended the verticals’ cuts near the hub. When its customer asked it to turn the hubs as well, creating a multi-machine, automated process seemed like a logical next step.
The photo below shows the castings as they are now received by the shop. The material is “nibral,” an alloy consisting of nickel, bronze and aluminum. It is useful for marine applications because it is durable and resists corrosion in seawater. Machining-wise, it’s said to be like stainless steel in that it’s a bit gummy.
Read more: Sometimes the Trickiest Part of CNC Machining Is Holding the Part