Three D printing creates the ER16 collet boxes sold at RDS. I make them myself. Well, the printer makes them. Once the printer is set up with filament and the design file loaded, it runs without my intervention for three to four hours. Then I pry the completed box and cover off the build plate.
I make several bright colors. Orange, red, yellow, and others. The bright colors are good, so the collet box can be easily seen in the shop. At first, I made them all orange. Now I stock them in the other colors. Usually whatever color I have on hand at the time. Availability is random. If you really want a specific color or size, I can make them at request.
The collets are a slight press fit into the pockets inside the box. This holds them secure using their own springiness.
I stock the 6 collet box as that is the number of collets Taig supplies in a set. 6 is the smallest practical size. I use a larger (15 collet) one and can make almost any size or practically any color. The plastic I use is call Polylactic Acid (PLA) and is made from bio-degradable material. Green for the environment as they will not last forever in the landfill.
The examples shown here are made with a color called see-through yellow. Bright yellow with a hint of green. One of these might be yours!