CNC machining applied to the field of automotive machinery

Tom Nichols of Ford Motor Machinery & Supply. Worth, Texas, said his shop specializes in high-end imported engines and Harley Davidson motorcycle engines, but now nearly half of his business is custom CNC work. Nichols owns six CNC machines, including the 5-axis machining center he originally purchased for the cylinder head porting. His equipment also has a digitizing probe that can be used to copy and import part dimensions into his MasterCAM CAD/CAM software.

The software digitizes the dimensions of the part to be replicated and determines the machining strategy and toolpath for making the part. The information is then exported to G-code, which is used to run the CNC machining equipment.

One of the custom jobs he did was to create a set of speed stacks for a set of alcohol-fueled vehicles. The velocity chimneys were first hand-patterned out of wood on a lathe, then the bench was tested and reshaped until the desired flow characteristics were achieved. The wood chimney is then digitized using a CNC probe and imported into CAD/CAM software to manufacture the part on a CNC machining facility.

Nichols said the digitizing probe allows him to accurately locate and mill the flats on the chimney, so it fits perfectly when mounted on the injection manifold. “It would have been a long manual job, but the CNC software and equipment made it easy to get started.”

Nichols has recently completed some custom CNC machining jobs including machining Hemi connecting rods, idler bushings for BMW supercharger kits, making parts for his own boring machine, brake caliper adapter brackets, connecting an Isuzu diesel engine to a GM pickup transmission matching engine adapter. , steering bushings for the 928 Porsche, a set of custom oversized Pony emblems for the Mustang, a Yahama luggage rack, and a metal replacement tail light mount for a Harley that was originally made of plastic and cracked easily.

Some of his non-automotive work includes machining heads for industrial compressors, making custom 10-inch multi-groove pulleys for gas well compressors, parts for aircraft maintenance work, torch mounts used by skydivers during exhibition jumps (US Army Golden Knights ), or even custom sports knives.

Manufacturing custom CNC parts requires not only a high-performance 5-axis CNC machine with good CAD/CAM software, but also support and all the associated equipment needed to develop and manufacture custom parts, Nichols said. . For automotive work, this might include flow tables, balancers, etc.

Nichols says he can do a small batch of CNC batch jobs, anywhere from one to 200 pieces at a time, or CAD/CAM programming if the customer wants to produce it themselves. 'If you've never done it before, CAD/CAM software has a lot of learning curve. You can master the basics in a few weeks, but it can take six months to a year to really learn everything the software can do time.'

Entry-level CNC equipment is inexpensive and can be learned quickly, Nichols said. “For $10,000, plus $3,000 for tooling and fixtures, you can get a small hobby CNC machine for low-volume custom parts. It’s learning about bigger, more expensive, and powerful Great way to learn CNC before CNC equipment.”

“CNC allows you to do more work with fewer people. Our shop used to have 6 or 7 people doing the work. Now we only need two people to do the same amount of work. CNC machines do what we used to normally do Most of the work done manually, but initially it takes a long time to set up the CNC job. Some jobs can take an hour or two to program and set up. But once that is done, the CNC can do everything else.” Coles said.