CR Onsrud wanted to show off their 5-axis Qube CNC machine at trade shows, so they got in touch with Coastal Enterprises to throw some ideas around. Onsrud regularly uses Precision Board as demo material on their routers, but they wanted to really highlight the capabilities of the Qube for high-speed machining and trimming of advanced materials used for aerospace, automotive, marine, defense and pattern shops. They decided they would fabricate a prototype of the Porsche 917k out of a custom-bonded Precision Board block live at IMTS 2018. This is how they did it.
While CR Onsrud sent a detailed drawing to Coastal Enterprises that laid out what the dimensions of the custom-bonded block would need to be, customers can submit anything from a rough sketch with dimensions all the way up to a detailed drawing. We’ll design a custom bonded step-tool from that sketch or drawing, saving you material costs and routing time.
In order for Onsrud to machine the Porsche 917k shape out of the Precision Board, it would need to be 74″ x 34″ x 18″ and fabricated from PBLT-15 Precision Board Tooling Board. Coastal would create three bonded blocks; one for testing at Onsrud’s facility in North Carolina, one for the International Woodworking Fair in Atlanta and one for the International Manufacturing Technology Show in Chicago.
According to Jeff Onsrud, Director of Sales and Business Development at CR Onsrud, “we typically will do a setup where we prove out the program and then do a final test cut at our facility.” He added, “this ensures that there are no machining defects due to bond lines, which is important to achieving a usable mold straight off the machine.”
Onsrud did the Porsche project in collaboration with Autodesk, using their Powermill software.
The PBLT-15 Precision Board pieces were bonded together using EP-76, a two-part epoxy manufactured by Coastal Enterprises.
“We add PB Granules to the EP-76 epoxy to match the density of the material when bonding pieces together” said Chuck Miller, President of Coastal Enterprises. “This allows for smooth routing straight through the material without having to take bond-lines into account. This also helps create an almost imperceptible bond-line in the finished piece and reduces issues associated with bond-line shrinkage and print,” he added.
When bonding custom step tools in-house, Coastal Enterprises has three adhesive options to choose from depending on the application and project requirements. In most tooling applications we use our EP-76 Epoxy adhesive, but we also offer PB Bond 240 and PB Fastset.
The three bonded blocks were shipped to CR Onsrud who took them on the road to the IWF show last August and the IMTS show last September. They sent us the video above from the live demonstration at IMTS of machining a Porsche 917k from a Precision Board bonded block.
Jeff added, “the Precision Board block was bonded together so tightly and the densities matched so perfectly that we didn’t even notice the bond lines when machining the material.”
CR Onsrud used their Qube CNC to rout the Precision Board with the following speeds and feeds settings:
- Total cycle time was around 16 hours
- Roughing feed rates were 500 inches per minute (IPM)
- Finishing feed rates were 400 inches per minute (IPM)
And here’s another look at that Porsche 917k prototype being routed by CR Onsrud.
Of course, the fine folks at CR Onsrud had a little fun with this project, posting updates to their Instagram account throughout the process. Our favorite is the “pretending to drive the car” photo.
The QUBE from C.R. Onsrud was developed for companies seeking 5-axis high-speed trimming and machining of advanced materials used in the aerospace, automotive, defense, marine, and pattern shop industries. This enclosed solution gives users a large work volume for machining molds, prototypes, and complex composite or thermoformed plastic parts while containing debris and isolating the operator from the machining zone and airborne particles. The machine design allows for various methods of work holding such as mechanical hold down and vacuum. Accommodation for oversized parts is achieved via removable side panels.
C.R. Onsrud, Inc. is located in Troutman, NC and specializes in 3-Axis and 5-Axis CNC Machining Centers, CNC Routers, CNC Mills, and Inverted Routers, primarily for the Composite Machining, Aerospace Industries, Plastics Routing, Hard Wood Routing, Panel Processing, Solidwood Routing, Aluminum Milling, Steel Milling, FRP machining, Composite Mold Making, Alloy Milling, Superalloy Machining, Carbon Fiber Machining, Carbon Graphite Machining, Door, Stair, Window, and Custom Millwork.
With its roots in Aerospace, Precision Board High-Density Urethane Tooling Board is specifically engineered to meet the demands of a broad range of tooling and tool making applications. Both PBLT Tooling Board (<200º F) and PBHT Tooling Board (<300º F), possess excellent machining characteristics and dimensional stability for tool making. Precision Board HDU Tooling Board is ideal for soft tooling and rapid prototyping because it can be more rapidly machined and it is more economical than alloy or epoxy-based alternatives.
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