by Bradley Trapp, Advanced Application Engineer

I will give five dollars to the first person who can name a manufacturing method that is 100% accurate, 100% of the time. It is my philosophy that we must always allow for, if not plan for, variance in any given manufacturing outcome. Depending on what’s next in your process, variance may not be problematic, but when secondary operations like CNC milling come into play, your part and fixture need to match up.

A common challenge with CNC milling is spindle failure, which is frequently caused by an improperly mounted part. This is where secure and accurate CNC milling fixtures can vastly improve operations and prevent damage to the milled part and CNC machine. But how do you ensure an accurate fixture for a part that may not be manufactured exactly to spec?

I’m glad you asked.

Modular, normalized SLS fixture for CNC milling
A modular fixture design allows you to match your fixture to the production outcome.

Avoid distortion on CNC milled metal parts

A huge opportunity with additive manufacturing that is not economically feasible with other manufacturing methods is the production of custom parts. Whether 3D printed parts take full advantage of design freedom for maximum complexity, or only deviate slightly, there is no added production time or cost to achieve unique outcomes. In the fixture world, this means fixtures can be 3D printed to match the actual dimensions of the production part as opposed to the idealized dimensions of the part design.                                                               

Using a digital workflow with 3D scanning, design and printing, an accurate, stable CNC milling fixture can be delivered to hold parts more reliably than any other method, every time.

Trust in tough and durable material properties

Selective Laser Sintering (SLS) is an additive manufacturing methodology that uses a high-powered laser to selectively fuse powdered material layer-by-layer. Materials available for SLS include a wide range of thermoplastics with robust performance characteristics, including high durability, toughness, and impact-resistance. These properties help SLS withstand the grueling conditions of the the CNC milling operation.

DuraForm® ProX® PA is one of 3D Systems’ tough and durable nylon-12 materials capable of withstanding the vibrations of the CNC process.

Increase production rate with modular fixture designs

The additive process makes producing accurate fixtures directly from digital files faster and more cost-effective than traditional manufacturing alternatives. Combined with the ability to create custom parts without added time or expense, additive manufacturing makes modular designs viable and desirable. A modular fixture design allows you to identify the typical deviation in a production part and have a range of assembly options for a matching fixture designed, printed, and ready to go based on the production outcome. Having quick access to secure fixtures means less waste in materials and time, and helps increase the productivity and profitability of your operation.

SLS parts offer up to a 40% cost savings vs. conventionally produced parts, and are delivered at accelerated speeds.

Interested in learning more about SLS for your next jig or fixture application? Download our Jigs & Fixtures Application Brief to learn more.