Page 17 - EDM Today Spring 2025

EDM Today Magazine EDM Today Magazine EDM Today Magazine
Feature Article On-Machine inspections are an important measurement Below are some examples of inspection methods that

can be utilized:
tool that can be utilized, but it will NOT replace or
eliminate a shop’s master calibrated inspection device
Level 1:
that is identifi ed in your company’s Quality Control
documentation. The reality is that the data from
• Hand instruments including micrometers
On-Machine/In-Process inspections is considered to
and calipers, etc.
ON-MACHINE -MACHINE
ON be “unoffi cial” or “For Reference Only” purposes. There • Standard gauge pin, gauge block,
is a sound and rational purpose behind applying a “For
feeler gauge sets, etc.
Reference Only” rule to On-Machine inspection data,
and the reason behind this is that any potential machine
• Custom go / no-go gauges (Polygon Solutions)
INSPEC equipment positional error or inaccuracy might also be Level 2:
INSPECTIONSTIONS
duplicated within the On-Machine measurement.
The use of On-Machine inspection is not a waste of time,
as this data can produce reliable and trustworthy values
• Standard Machine Pick-Up/Measurement Cycles
By Brian Pfl uger EDM Today Magazine EDM Today Magazine EDM Today Magazine
that help reduce the need for undesirable re-machining
> Wire EDM
processes. The fundamental concerns have to do with
Machine Tool and Master Inspection Device. In an effort
using the wire itself as a probe utilizing the
A measure of one’s greatness is reserved for the eye of the beholder, the potential mismatch and discrepancy between the - Most machines can perform measurements
to trust the on-machine inspection data, it is necessary to
Brian Pfl uger is an EDM however for machines, many forms of measurements exist that can be regularly perform correlation measurements between the standard Pick-Up Cycles on the Control
utilized to validate the level and magnitude of achieved excellence. The three
Regional Sales Manager for primary machine performance factors that are universally understood and machine tool and the master inspection device to ensure > Sinker EDM
Makino, but has held different applied to our work are: Cycle Time, +/- Accuracy, and Surface Finish. While that both pieces of equipment produce consistent and - Most machines can perform measurements with a
positions in the Application Cycle Time is easiest to comprehend and judge, the validation of Accuracy reliable values. Rigid Spindle Probe utilizing the standard Pick-Up
Engineering and Product and Surface Finish requires the use of specialized tools and equipment. It is likely that a Master Inspection Device will be rated Cycles on the Control
Management Teams over his for a higher/fi ner tolerance level than the Machine Tool, > Some machines support the recording and
20+ years at Makino. Brian Traditional process methodology transfers a fi nished workpiece from its so the creation of a measurement correlation process exporting of measurement data
machine of manufacture to a dedicated inspection device, such as a
started his career as a 4th CMM (Coordinate Measuring Machine) for the fi nal validation of accuracy. will also need to defi ne a specifi c +/- Tolerance Level
where matching measurement values are achieved
Generation Tool and Die Maker While this method is sound, it requires the part to be transferred back to EDM Today Magazine EDM Today Magazine EDM Today Magazine
(interestingly a 3rd Generation the machine and set up a second time to be re-machined to correct any between the equipment. This is a key step in establishing
EDMer), and also as a accuracy fl aws, inducing undesirable added labor and time to the overall reliable “trust” with the In-Process inspection data!
Machine Trades Instructor. process. To minimize this extra and unwanted manufacturing cost, basic
accuracy checks can be performed while the part is still set up in the
machine, and this On-Machine inspection can include a growing list
of high-tech tools.
may vary by machine manufacturer EDM Today Magazine
Before we jump into the technical EDM-specifi c content related to
On-Machine/In-Process inspection, we need to address the primary
concern and restrictions related to ISO Standards. While On-Machine
inspections are a useful and benefi cial tool, they DO NOT replace the
need for a fi nal validated inspection process. ISO Standards establish Level 3:
three critical rules that we must follow in the machine world, which EDM Today Magazine EDM Today Magazine
are also part of a company’s defi ned Quality Control System: • Some machines offer and support more advanced
The same machine that produces a part CANNOT be used to inspect measurement device options such as CMM-Style
Trigger Probes or Vision Systems
the fi nal “offi cial” measurements of a workpiece.
A Master Inspection Device is identifi ed in the Quality Control System that • These optional enhanced measurement capabilities
is also regularly calibrated back to a master certifi ed specimen. ON-MACHINE INSPECTION METHODS • The use of these higher-level inspection devices can
Brian brings a wealth of knowl- The equipment being used for inspection must be capable of The vital principle to consider with a part’s measurement include recording and exporting of measurement data
edge and shop experience to measurements that are ten times fi ner than the target accuracy for check while it is in the machine is to inspect to a target
our EDM Today readers, and he statistical purposes. +/- Accuracy Tolerance level that is both practical and
is a regular contributor to the reliable given the chosen inspection method. Tactful ADVANCED ON-MACHINE INSPECTION OPTIONS
magazine with special articles measurement of parts while they are still set up in the Trigger Probes
machine is a useful practice prior to removing a work-
and content. Brian’s primary BENDING THE RULES? EDM Today Magazine EDM Today Magazine EDM Today Magazine
responsibilities in his current There is a universal desire to have an operator press the “EZ-Button” and piece, but the inspection method needs to be suffi cient CMM-style Trigger Probe options are available for
most machines, and these serve to enhance the setup
Regional Sales Manager role have the machine execute everything fl awlessly and within tolerance…all and adequate to support the desired level of precision to accuracy capability. Probes are commonly offered for
be useful. On-Machine measurements can be performed
is supporting salesmen and Auto-Magically! While the appeal of producing perfect parts without having using hand tools or gauges and can also include auto- use on Wire, Sinker, and EDM Drilling machines, and the
customers with engineered to think or apply one’s skillsets to the process is understandable, we must matic measurement cycles made by the machine itself. most frequently used probes are from Renishaw such
EDM solutions. concede that reality is VASTLY different. We do want to leverage and yield No one method is better or more important than the as the RPM400 or MP250, which offer distinct levels of
the most accurate results from On-Machine/In-Process inspections and
EDM Today Magazine EDM Today Magazine EDM Today Magazine
trust the data the Machine Tool is providing, but ISO Standards do not other, as the inspection constraints are predicated by the precision. Some industries prefer the use of Trigger
recognize these measurements. part’s specifi c accuracy requirements. (Continued on next page)

14 EDM Today, Spring 2025 Issue EDM Today, Spring 2025 Issue 15