Micromachining Hairy Little Cubes

Micromachining is an astounding world of technology that continues to push the limits of possibilities, often in the medical and plastic injection mold making industries. By definition, his somewhat other-worldly type of CNC machining occurs in within a 10 mm sized cube or with details less than .10 mm.
A human hair is about .10 mm in diameter, which provides a good reference for the size of parts processed by micromachining. So, you see, you might just find yourself machining hairy little cubes someday.

To me, the amazing thing is that this type of machining is commonplace in some companies. How can you find an end mill small and accurate enough to work with a .10 mm detail?

Micro EDM

Machine tool companies, such as Makino and Sodick have developed highly sophisticated sinker and wire EDM machines that boggle the mind with their advanced capabilities.
The incredible detail, fine surface finish and accuracy is impressive indeed. Of course, any type of micro machining involves a tremendous learning curve and must be approached with this understanding.

Medical staples and tiny gears

Some micromachining applications include surgical staples, miniature gears, custom molded medical parts for hearing aids, and computer components. This type of component is exactly what the layman has no clue about.
Generally, people just want to use a tool or device and trust that it works right every time. Only when there is a problem are they forced to consider how it was made, designed or assembled.
Come to think of it, how do you hold one of these 10 mm plastic parts and assemble it into something like a hearing aid with miniature gears. I’ve even seen pictures of gears so small they were microscopic!

Special equipment is required to run these injection molds, you certainly cannot do it on your basic 250 hydraulic press! The auxiliary tooling and robotics must also be specially manufactured to handle the tiny parts.

I cannot imagine how anyone could time an angular shut-off, for instance, for the core and cavity blocks. What if you need to add a slide or lifter? How big are the ejector pins? It is hard enough using 1 mm ejector pins, much less a pin smaller than this!
Imagine polishing a part with .10 mm details! “Whoops, I think that was actually a molding detail, looks like we might need to make this part over again”. This requires a reassessment of the entire mold making process.