EDM'ing a Sweet Tool Height Setter

Last modified: June 13, 2024

While browsing through the posts of Practical Machinist, I stumbled upon this amazing project. This individual utilized an EDM, a mill, and a lathe to craft a high-quality tool height setter.

EDM, an abbreviation for "Electrical Discharge Machine," uses electric sparks to break down the metal.

There are EDM's that use the method of plunging a conductive electrode into material, and there are those that use wires. The latter functions much like an incredibly precise scroll saw.

Despite being a slow process, EDM offers the unique capability of creating shapes that would be nearly unattainable with other techniques. Furthermore, it can be employed to slice incredibly hard materials, a feature exploited for this particular project with the use of carbide.

A Tool Height Setter is used to measure the height of your tools so you can fill in the tool table on the CNC to adjust for that height.  Some use electronic touch sensors, and some use an indicator like this one.

Check out the link.  Here are some sample pix from the article:

Three dark gray metal parts on a white workbench or table in a machine shop.

First, use a Wire EDM to cut all the parts out.  EDM is slow, but can do things that just can't be done any other way...

A metal cutting tool with a carbide insert, used in wire EDM process.

For example, how about wire cutting a circular touch pad out of a brazed carbide tool so your endmills would nick the tool pad?

A silver bearing base with four evenly spaced holes and a white dial gauge displaying inch and millimeter measurements.

Bearing base provides three points of contact so the tool setter sits flat on the machine table and is less prone to cocking if there is a chip there...

Dial indicator held by a hand.

The finished Tool Setter is a gorgeous piece of shopmade tooling...

Lots more pictures of the build over on PM!

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