EDM stands for Evil Demon Magic

During my materials research time, I had the opportunity to work on the EDM, or electrical discharge machine. Seen here:

I know, it's a beast.


Basically, the graduate student I was working under said, "Read the operating manual." So I did!
The first words that the manual said, "'You may think that EDM stands for 'Evil Demon Magic.'  But it actually stands for 'Electrical discharge machine.'" I thought this way really funny and credited the Japanese company, Sodick, for having a sense of humor in its technical manuals.

This is how an EDM works:

• A wire (for this "wire EDM") is strung in water. Don't worry, the water is de-ionized so it doesn't conduct electricity.
• A large current is passed through the wire.
• The wire, basically, melts everything in it's path (as long as it's metal)
• The water washes the melted material away.

Once a grad student told me he stuck his hand in the water to take a picture of the process... I wouldn't recommend this action, but he was living proof that the water doesn't conduct electricity.

Funny story: Once I opened to front door to the EDM while the basin was filled with water.  You know what happened...

Water spilled everywhere! Afterward, my adviser laughed and said that he could never get the door closed after he opened it. I didn't feel so stupid afterward.

Big Machines: They aren't that scary.

I came to college not knowing ANYTHING about manufacturing or combustion engines. For you worry-warts out there: that's okay! A little secret: most of the guys in my classes didn't know either. 


Here's Serena's basics of manufacturing:

1. What is the design of your part? If the part's feature is circular: use a lathe (like how they make baseball bats!).  If the part is basically cutting away material in straight paths: use a mill or drill press (which makes holes). If it's super intricate, use an EDM (Electric Discharge Machine) but chances are you won't need one right away.
2. It's all about positioning.  Where does the tool go? Define the paths on paper (or in your head) before you even get CLOSE to a machine.  Easy enough. Actually sounds kinda fun. 
3. Figure out how the machine (mill, lathe, EDM) works.  A basic shop class will take care of this. Most of the hard work is done in your head. 
4. Manufacture your part! See...it wasn't that hard! 

Next post: my experience with EDMs and the Intron, a tensile testing machine.