pic: 294 - This is How we cut (wire EDM)

The wire EDM we have used from time to time. An awesome machine, but it’s temperamental with aluminum (keeps breaking the wire).

294 plans to fully use all of these resources next year :slight_smile:

Could you explain what Wire EDM is and how and why it is used please?

They can cut any shape as it is wire (very, very thin) that does the cutting with electricity.

Team 195 cut their wheels with one.

We’ve used it to cut keyways, odd sized hex holes, strange hubs (5mm w/ 4.5mm flat), etc…

The best description I can give is that it’s like a waterjet.

Although, from what I’ve heard, EDMs leave a cleaner edge than waterjets.

Think of it as a very small wire, and sparks are made to jump from the tip of thr wire to whatever metal workpiece you want to shape. The sparks vaporize a tiny amount of the metal workpiece, and if you do it often enough you spark a hole into the workpiece. Now, control the spark and wire tip position very precisely, and you can shape some really complex shapes. Unlike a waterjet, you don’t have to cut all the way through.

EDM - Electical Discharge Machining.


Well… for the machines we have that is halfway correct.

We have a wire EDM which has a wire that goes through the part and cuts profiles.

The other is called a “Sinker” (I think) which as a shaped electrode (like a hex shaft) that when pushed into the piece, takes of .003 at a time. This doesn’t have to go all the way through.

as well as leaving a cleaner finish, they can machine much smaller radii, and can hold much closer tolerances.

Things that describe a wire EDM machine:

>Swiss-Watch Accurate
>Cuts things you can’t cut any other way
>Slower than Molasses on the dark side of the moon in january. (Rough your parts with a standard CNC machine first if possible, or wait a day or so)

If you can…
>See if you can use a contact EDM machine (carbon/graphite shaped electrodes) which cut faster.

They make cool stuff… but see if you can make it another way first! (Broaching, etc.)


Add down when you need them and that’s the lot, I think. This machine was down for some reason in February–and both 330 and 294 needed to put a keyway in a sprocket right at the end of build! (ECC didn’t have the right size broach at the time. They got one a week or so later.)

Adding to this:
> it can cut through very thick metal - I have seen as much as 4 inches, but very slowly
> it can make a tapered cut from the top to the bottom through the metal thickness
Both of these come in handy for making molds and punch press tools.


im so jelous :frowning:

The EDM is an amazing tool, we used one last year for getting a coupler done for the window motor, and it turned out great.