Using electrical discharge machining tooling makes perfect sense any way you look at it; so why would any plastic injection mold making company not use it?
There are only two reasons, and one is almost impossible.
The first is that they don't know how much time and money they will save.
The second is that they can't afford to buy it. This might be true if you are starting out on a shoestring budget.
How did EDM tooling develop?
In the old days of electrical discharge machining, there was no tooling available. Mold makers had to invent their own and they came up with some very clever methods of holding electrodes. But gradually things developed into a systematic approach that could be more universal in nature and would be much simpler to use by anyone.
A Swedish company, System 3R was one of the first companies to dramatically change the way EDM operators held their graphite and copper electrodes. Using some very basic principles, namely that you need to register you electrode in 3 reference planes: X,Y, and Z from the Cartesian Coordinate system, they built very high quality holders for the EDM industry.
This was a quantum leap forward compared to the old Vee blocks, angle plates and jury-rigged systems of the past. 3R made sense, totally. It was rather expensive though, and most shops bought a little starter kit and began experimenting with it.
Soon, almost any American mold making shop had some kind of electrode holding system in place. There are systems from Germany, Switzerland, Sweden and probably other countries as well. All of these systems are very good and any company would be wise to invest in one.
Why would a mold making company still be in the dark ages?
Like a lot of things, people don't like change. Plus, the ones holding the purse strings usually are not the ones who have to use the antiquated electrode holding system, so they don't have any idea how difficult it is to locate multiple electrodes over a workpiece all day long. Electrical discharge machining is difficult enough, why not make it easier and more reliable?
Perhaps some simple electrodes that are always the same size, such the pre-ground blanks that are accurately sized don't require a purchased system. Yet even these require an accurately made set of holders made in-house.
Another reason some shops still use the old method of stick electrodes is because their labor is so cheap that they can afford to pay somebody to manually align and locate all their electrodes in the EDM machine. Places like China and Thailand fall into this category.
Your mold making operation needs EDM holders
If you are serious about plastic injection mold making, you will need to investigate electrode holders. In the long run you will save many, many hours and dollars. Not only that, but you will not need such a highly skilled toolmaker to make the set-ups, let the tooling do the repetitive work and free up your skilled help to do what no machine can do! Bring your electrical discharge machining up to date and use the tooling the way it is designed! Old habits die hard.
Randy Hough
Plastic Injection Mold Maker
http://www.global-plastic-injection-molding.com
"You know Dad, I've been thinkin', one is a lot more than zero!" my son, Thomas, age 5.
Article Source: http://EzineArticles.com/?expert=Randy_Hough
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