EDM (electric discharge machining) Machine

Homemade plunge EDM (electric discharge machining) machine built based on the book "Build an EDM" by Robert Langolois. (https://secure.villagepress.com/stor...age/2/item/797) 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. The motor from the same clothes dryer is still in use on my http://www.homemadetools.net/forum/g...9966#post41061.

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 the major components with and without the case cover installed:
Attachment 10526 Attachment 10527

Here is the machine setup for cutting a part:
Attachment 10529 Attachment 10530

These are a couple of pictures of items that were machined using the EDM. On the left is a piece of hex stock that I machined with a small electrode. On the right is a neodymium hard drive magnet that I cut a circle out of.
Attachment 10528 Attachment 10531

In the video below I talk about some of the major parts used to build my machine and show a couple of parts that I cut using the EDM. At the end of the video there is a short clip of the machine in action.

https://youtu.be/-a1JEWbnvMo

The posting of this tool finishes off the list of homemade tool I posted in my original forum post about a year ago in April 2015 (http://www.homemadetools.net/forum/s...omething-17270)

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Thanks scorch! We've added your EDM Machine to our EDMs category,
as well as to your builder page: scorch's Homemade Tools. Your receipt:

<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="http://www.homemadetools.net/edm-machine"> <img src="/uploads/149899/edm-machine.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="http://www.homemadetools.net/edm-machine">EDM Machine</a> <span> by <a href="http://www.homemadetools.net/builder/scorch">scorch</a></span> </div> <div class="tags">tags: <a href='http://www.homemadetools.net/tag/machining'>machining</a>, <a href='http://www.homemadetools.net/tag/edm'>EDM</a> </div> </div> </div> </div>
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scorch,

This is amazing work and wonderful ways to source the parts. This is great information and lots of references. I think you will have many views for this project.

Thank you, Paul

Thanks Paul. The EDM was an interesting project but I have yet to find a practical usr for it. This project was more about the journey.
Scorch

Congratulations scorch - Your EDM Machine is the Tool of the Week!

You'll be receiving an online gift card, in your choice of Amazon, PayPal, Giftrocket, or bitcoin. Please PM me your current email address and I'll get it sent over right away.

This is your fourth Tool of the Week win. :rocker:

One more and you'll join Brendon, Christophe Mineau, and rossbotics as a 5-Time Tool of the Week winner, and the silver wrench-on-pedestal graphic will be added to your trophy showcase in your postbit beneath your avatar. Here are all of your wins so far:

<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="https://www.homemadetools.net/forum/plastic-injection-molding-machine-17452#post23946"><img src="/uploads/115362/injection-molding-machine.jpeg" alt="Injection Molding Machine" /></a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="https://www.homemadetools.net/forum/plastic-injection-molding-machine-17452#post23946">Injection Molding Machine</a> <span> by <a href="/builder/scorch">scorch</a></span> </div> <div class="tags"> tags: <a href="/tag/arbor-press">arbor press</a>, <a href="/tag/electrical">electrical</a>, <a href="/tag/cylinder">cylinder</a> </div> </div> </div> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="https://www.homemadetools.net/forum/one-day-foundry-casting-aluminum-18069#post25050"><img src="https://www.homemadetools.net/uploads/117692/aluminum-foundry-7.jpeg" /></a></div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="https://www.homemadetools.net/forum/one-day-foundry-casting-aluminum-18069#post25050">Aluminum Foundry</a> <span> by <a href="/builder/scorch">scorch</a></span> </div> <div class="tags">tags: <a href="https://www.homemadetools.net/tag/foundry">foundry</a></div> </div> </div> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="https://www.homemadetools.net/forum/gingery-lathe-29966#post41061"><img src="https://www.homemadetools.net/uploads/133494/gingery-lathe.jpeg" /></a></div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="https://www.homemadetools.net/forum/gingery-lathe-29966#post41061">Gingery Lathe</a> <span> by <a href="/builder/scorch">scorch</a></span> </div> <div class="tags">tags: <a href="https://www.homemadetools.net/tag/lathe">lathe</a>, <a href="https://www.homemadetools.net/tag/chuck">chuck</a>, <a href="https://www.homemadetools.net/tag/motor">motor</a></div> </div> </div> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="https://www.homemadetools.net/forum/edm-electric-discharge-machining-machine-43313#post62462"> <img src="/uploads/149899/edm-machine.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="https://www.homemadetools.net/forum/edm-electric-discharge-machining-machine-43313#post62462">EDM Machine</a> <span> by <a href="https://www.homemadetools.net/builder/scorch">scorch</a></span> </div> <div class="tags">tags: <a href='https://www.homemadetools.net/tag/machining'>machining</a>, <a href='https://www.homemadetools.net/tag/edm'>EDM</a> </div> </div> </div> </div>



Nice work and congrats again. :thumbsup:

Nice build! I got the book many years ago from Lindsay Books. Sadly he closed up shop.

I wonder how this would work with a CNC table, as opposed to a plasma cutter.

Possible practical uses for your EDM. I don't know much about EDM but more than 30 yrs ago I had an Evinrude OBM that I was overhauling and many of the S/S bolts were completely seized into the alloy and sheared off. The solution was to use a portable EDM machine to erode the stainless bolt from the alloy. If I remember rightly, a dam of Plasticine was built around the sheared off stud, it was filled with fluid and the EDM ate away all the stainless and left the alloy threads intact. I never did work out how it managed to do that without destroying the alloy. A colleague did the work for me and for about a year the machine had some intermittent use doing similar work, and then I never heard of it being used again in the next 30 years. Today they tend to machine out studs like this and perhaps fit Helicoils, but at the time it was a good solution to my problem.

These people are keeping the books alive. Glad I found them a while back. I have quite a few of the old books and find them very interesting. Plan on getting a few more.
Your Old Time Bookstore

Quote:

---

Originally Posted by Pa1963

I wonder how this would work with a CNC table, as opposed to a plasma cutter.

---

Most commonly EDM is used in CNC applications in the form of wire EDM. With a wire EDM the electrode is a wire that is feed between two spools. The use of the wire keeps the electrode size constant because there is always fresh wire being fed into the cutting area. If you CNC with a plunge EDM you would likely need to account for the tool wear.

During my apprenticeship as a Fitter and Turner we used EDMs to form forging dies, a carbon electrode was copied of the plaster master and then burnt into the blocks of tool steel, we also used copper wire for removing broken drills etc. The coolant we used was a mixture of kero and light oil.

Congratulations Scorch,
I have operated EDM machines wire and sink but never thought a home made one was possible especially from used parts. As for uses we used to erode out sheared studs from engine parts and also erode holes in hard steels with no loss of hardness.

Bloody useful for making any form of internal shaft features such as keyways or splines. one very special use would be for cutting hex for allen keys into eccentric bolts for making your own mitebite work holding clamps. I started a plunge EDM about four years ago and well pretty much still starting the project. I do have a few parts obtained for the build but other things got in the way like getting into a CNC conversion for an old mill. A friend of mine in Canada is also big into CNC milling and has started researching his own build of a wire EDM. To say his influence isnt rubbing off would be a darn right lie. My refference source was the other book, yet only two authors spring to mind when it comes to home built edm. The one mentioned above and Benjamin Fleming "EDM how to book" Another good contact/source is
https://baxedm.com/

who knows one day i might actually pull my finger out and get on with it, that and the Quad-Copter