EDM

Basics

• Stands for Electric Discharge Machining.
• It is simply a spark between an elecrtode/wire (Depending on which machine variant is used) and a workpiece that are seperated by a dielectric fluid (Usually high purity water (Double Distilled or Deionized) or oil)
• It does super precise cutting and small hole drilling in electrically-conductive materials.

About

• Good explanation + Demo in this video at 13:26
• Uses 0.25 mm brass wire for cutting, Mcmaster has 0.5 mm wire - $30/lb - [1]
• Voltage is 50-300V. Current for 1" cut below is 35A.
• 1 pound of wire used per hour to cut a 1/2" hole in a 3" piece of hard metal. - [2]. that is $5 in wire cost. About $1 per inch of metal.
• 10x slower than waterjet - [3]
• Waterjet appears to be much better for the speed and cost. But EDM advantage is 10x more precise - [4]

Examples of EDM Cut Objects

• The following was cut using a high precision Wire-Cut EDM Device. The Cut is so precise that the shape can seem to dissapear into the cube it was cut from when it is reinserted:

<a href="//imgur.com/DAs75ze">THE FINAL FORM</a>

<script async src="//s.imgur.com/min/embed.js" charset="utf-8"></script>

Source

Existing Open Source Designs

Youtube #1

• DIY, cuts 1" stainless at 2 mm/min - [5] Howto - [6]

Book on DIY EDM machines

• [7]

Youtube #2

• [8]

Books and Starter Kits

• [9]

MIT Design?

• MIT Machines That Make - [10]

BOM

EDM wire

• $40 for 6 lb - [11]

See Also

• Open Source Die-Sink EDM Machine
• Open Source 3 Axis Wire-Cut EDM Machine
• Open Source Robotic Arm Wire Cut EDM Machine

Useful Links

• Wikipeia Page On Electrical Discharge Machining
• Youtube Vidoe: DIY, cuts 1" stainless at 2 mm/min - [12]. Howto - [13]