Page 19 - EDM Today Spring 2025

Probes, as these systems do not apply any electrical function may also incorporate 1 or 2-Axis Rotary Table capability and functions that a dedicated off-line Vision
power to the part for touch sensing. confi gurations on the machine. For Wire EDM machines, System has, and this is equivalent to the On-Machine
probing can include the ability to pick-up the workpiece probing vs. CMM comparison.
in the Z-Axis to perform 3D Leveling of the part where the EDM Today Magazine EDM Today Magazine EDM Today Magazine
machine calculates a U/V-Axis shift so that the wire is
perpendicular with the workpiece conditions. CLOSED-LOOP MANUFACTURING
Thus far we have examined methods for On-Machine
measurements as a means of improving setup
accuracy and for evaluating the produced feature size.
To this point, we are leveraging the machine tool to
automatically perform some measurements that an
operator can use to make a judgement call before
There are other more advanced optical inspection Tool
removing the part from the machine. While this approach
Holders available that can encompass digital cameras
is benefi cial, it still requires a decision be made by the
and display screens. One such system offered by
human operator, but there does exist an even higher
ZeroSet can perform measurements of complex
For Sinker and EDM Drill machines, probes are usually EDM Today Magazine EDM Today Magazine EDM Today Magazine
next-level form of On-Machine inspection called
contours. The advantage of these tools is that it does
located on the centerline of the Z/C-Axis, which place not interface with a machine’s Controller, allowing an Closed-Loop Manufacturing (CLM) that provides further
the probe on the same axis that machining will be operator to add some new tricks and capability to an machining process advancements.
performed. This confi guration allows probing to be On-Machine Trigger Probes generate location point data older machine. These units do require an incoming Closed-Loop Manufacturing incorporates On-Machine/
performed anywhere on the workpiece that the machine that is very useful for setup and part alignments, but this power source like an extension cord, so there are In-Process inspection and utilizes this data in a feedback
will be able to access. For these machines, the Trigger point-cloud data is minimal and low in quantity. In-Pro- some strings attached! loop to make decisions and changes to the process.
Probe is normally assigned and stored in the machine’s cess probing of parts is a valuable tool to measure basic Think of CLM as a form of AI (Artifi cial Intelligence) for
ATC (Automatic Tool Change) system, and the Probe feature sizes for judgement before a part is removed the machine where the integrated systems can measure
Body interface utilizes the same Tooling Chuck system from the machine, but it is important to understand that and automatically adjust the program to enhance the
that is on the machine. Designs for Wire EDM probing this basic point data is insuffi cient for a formal inspec- Complex Systems accuracy outcome. This technology allows the machine
systems do vary, as some manufacturers place the probe tion. A full-blown CMM is still FAR more capable than Some EDM manufacturers offer advanced Vision System tool and its systems to adapt and make modifi cations
to one side of the Upper Head, whereas others place the Trigger Probes used on a machine tool, as CMM’s can options that are fully integrated into the machine’s Con- on its own, as the machine is applying the measurement
probe on the same centerline as the wire. perform full Point Scanning that captures thousands of EDM Today Magazine EDM Today Magazine EDM Today Magazine
trol system. This type of solution normally entails some
data as Input and Output for process decisions.
Regardless of EDM machine type, the use of a Trigger data points that plot the entire geometry form of a part. modifi cation to the machine and requires the use of spe-
Probe requires the establishment of an internal Offset cial dedicated software to run the Vision System. These One such system was developed by EDM Intelligent
within the machine. This internal Offset is used as a units can support optical magnifi cations upward to 100X, Solutions (Bartlett, IL) where they integrated an Alicona
reference point that all probing measurements will be Vision Systems but can also feature a digital zoom up to 400X, and they Vision System on a Sinker EDM. The Vision System halts
sourced from. On Sinker and EDM Drill machines, a Table There are various options available for magnifi ed vision also include special lighting needed for measurement. operation and takes measurements of the part after the
Ball is placed within the work tank that is used as a inspection and setup of parts, and these solutions can completion of each power setting. The integrated soft-
common reference base point for all locations, including range from simplistic to complex fully integrated systems. ware then utilizes the inspection data to make minute
the probe, electrode(s), and workpiece. For Wire EDM’s adjustments to the program for orbit pattern size and for
confi gured with a probe, a special alignment device is Z-Axis depth. This highly advanced solution has helped
used to establish an internal Offset between the probe Simple Systems EDM Intelligent Systems to signifi cantly improve accura-
and the center of the wire. cy and achieve consistent +/- 1-micron results.
Many tooling manufacturers, such as System 3R, Erowa,
For most EDM machines, probing routines piggy-back Hirschmann, and others, offer special optical mea-
and utilize the standard canned Pick-Up Cycles within the surement tools that utilize a machine’s Tooling Chuck EDM Today Magazine EDM Today Magazine EDM Today Magazine
machine’s Control. This does provide some convenience System. These special Tool Holders contain mounted
and familiarity to the operator, as most modern machines microscope reticle objectives that are manually loaded
feature user-friendly graphically driven pick-up routines. into the machine, and they employ useful magnifi cation
Probing routines can also be programmed using G & levels that can range from 20X to 50X. This style of tool
M codes, which are attractive for repetitive production is mostly used on Sinker EDM and can be used to manu-
applications. ally measure a feature by jogging the machine axes, but
A key advantage of Trigger they also offer useful visual inspection of the surface
Probes is the ability to per- quality of a part.
form more complex Pick-Up
functions. One such exam- The addition of an On-Machine Vision System enables IN SUMMARY
ple is 5 or 6-Point Nesting automatic measurement of part features inside the ma-
location pick-ups found in EDM Today Magazine EDM Today Magazine EDM Today Magazine
chine using sophisticated metrology camera and soft-
To note, there is no one best or perfect inspection
the aerospace industry. This ware technologies. These systems can be utilized to fi nd method out there! Every part contains and is subject to
probing function allows a part’s datum or start location, and can also perform its own unique size and accuracy requirements, which is
the machine to locate the full contour geometry size measurements with a Best-Fit why diverse types of inspection equipment have been
workpiece in 3D space conclusion back to CAD Data (this shows a +/- deviation developed. Each inspection method has its own
and calculates locations of measurements back to the theoretical programmed strengths and weaknesses, but part cleanliness (or lack
based upon the 6 degrees CAD data), and this data can be saved and exported from thereof) can negatively affect the reliability and accuracy
of freedom (X/A-Rotation, the machine. While these systems are quite capable, of measurements. Due to their high magnifi cation,
EDM Today Magazine EDM Today Magazine EDM Today Magazine
Y/B-Rotation, Z/C-Rotation), the On-Machine Vision Systems do not contain the full
and this higher-level setup (Continued on next page)
16 EDM Today, Spring 2025 Issue EDM Today, Spring 2025 Issue 17