A CNC machine can cut through a metal clamp if something goes wrong, potentially damaging the cutting bit. Plastic clamps are a safer option: the bit can pass through them without taking the same kind of damage. But replacing bought clamps over and over can become a nuisance—even if each one is inexpensive.
A 3D printer makes those sacrificial parts easy to replace. The clamp’s plastic costs only a few cents, and a print usually takes around 15 to 20 minutes. Printing a batch means having spares ready in the workshop instead of waiting for a new order to arrive.
There are also free clamp designs available online, including files shared by Carbide 3D. You can use an existing design, adapt a clamp that is usually made from metal, or create one yourself.
Printing makes experimentation inexpensive, too. If a new clamp design doesn’t work out, it’s only a few cents of plastic lost. For the author, that’s the real advantage of 3D printing: parts that once felt costly to throw away can now be remade at home for pennies.