I made the majority of this homemade EDM a long time ago. Recently I have been finishing this project by making a better structure for the linear actuation, adding labels to the controls and other miscellaneous items. In the video below I discuss the EDM and show a couple of the parts that I have cut. At the end of the video you can see a short clip of the EDM in action. At the end of this BLOG post I included pictures of a neodymium hard drive magnet cut using this EDM.
My homemade plunge EDM (electric discharge machining) machine built based on the book “Build an EDM” by Robert Langolois. The book consists of a series of articles that originally appeared in The Home Shop Machinist.
I deviated from the book in a couple of ways. First I sourced some of the components from scrap electronics and an electric clothes dryer that I picked up for free on the side of the road. The main transformer came from a microwave oven along with a cooling fan. A smaller transformer was sourced from an old stereo. The heating coil that I used as a power resistor was also taken from the old electric clothes dryer.
Additionally I used a sand cast aluminum part to support the linear actuator components and finished the whole thing off with a few custom 3D printed parts to fasten the linear actuator parts together.
Here are a couple pictures of a neodymium hard drive magnet that I cut using the EDM. Here is the before picture with the electrode that I used:
This picture shows the magnet set up for cutting. The magnet is placed on a utility knife blade which is clamped into a small plastic vice.
Finally here are the two parts created by cutting through the magnet with the EDM.