Probing and Inspection

Overview#

A touch probe is a sensor mounted in the spindle (or on a tool setter) that reports when its stylus contacts a surface. Used on a CNC machine, it replaces manual edge-finding and indicator work with a repeatable, automatic cycle. Fusion's probing support generates probing operations that use the probing cycles (macros) on your CNC machine, or a probe path, to locate stock and features and to update the setup's WCS Offset or verify features against tolerances.

Autodesk's "Inspection for manufacturing" supports probing with CNC machines and inspection with manual instruments such as calipers and micrometers. Probing serves two broad purposes:

1. Setup: locate stock or a feature and update the WCS Offset (G54 and others) so the part can be clamped anywhere and the program still hits the right place. For freeform parts such as castings and forgings, Part alignment calculates an alignment from surface inspection results.
2. Inspection: measure features in-process (holes, bosses, surfaces, walls, channels, corners) and act on the results; with a probing cycle the tool wear stored in the controller can be updated, and if measurements exceed tolerance the machine can be instructed to stop with a message.

Autodesk stresses that all manufacturing operations need a supporting post processor, and that probing cycles work only if your machine has probing functionality and your post has been modified to output the cycles.

Note: licensing, per Autodesk's inspection topics: Probe WCS and Manual inspection are not marked as extension features. Probe Geometry, Inspect Surface, Part alignment and Live part alignment (and importing results in real time through a live connection) are marked as part of the Manufacturing Extension. See the manufacturing extensions page.

Where to find it#

• Inspection > Probing > Probe WCS (and Probe Geometry and Inspect Surface in the same area); Inspection > Manual > Create Manual Inspection / Record Manual Inspection; Inspection > Actions > Live Connection / Import Inspection Results / Inspection Report; Inspection > Manage > Machine Library.
• Tool Library: the Probe tool type; the Fusion Library has a Probes folder and a Samples/Sample Probes library.
• The post and its probing properties.

Probe tools#

Create or pick a probe in the Tool Library (type Probe; the Fusion Library has a Probes folder). In the probe operations, feed settings include Link Feedrate (link moves, shown yellow on the canvas), Lead-In Feedrate (lead moves, shown green) and Measure Feedrate; with two touches, the first is at the lead-in feed and the second at the measure feed. Raising the lead-in feed does not change measurement accuracy but can cause false triggers if machine acceleration is high.

The probe must be calibrated on the machine; Fusion relies on the control's values (general practice).

Probing operations#

Probe WCS#

Creates a probing operation to locate stock and features and update the setup's WCS Offset. The dialog has Tool, Geometry, Heights and Settings (Actions) tabs.

1. Inspection > Probing > Probe WCS.
2. Tool tab: select a probe.
3. Geometry tab: choose the Probe Mode (Model or Stock), then click faces on the model or stock; pick a Probe Type (options depend on the faces selected).
4. Optional: Override Driving WCS with a WCS Override number so the probe is driven from a different coordinate system than the setup's WCS Offset; Print Results shows results on the controller and generates a results file you can import.

Probing cycle positions include single axis, corner, block center, rectangular cavity center, circular boss center, circular hole center, rectangular and circular cavity with islands, and between two walls/faces. You can set tolerances to confirm that stock or the part is correct and loaded properly, and instruct the machine to stop if not.

Probe Geometry (Manufacturing Extension)#

Measures and verifies critical features such as holes, bosses, surfaces, walls, channels and corners, using either machine probing cycles (where position, angle and upper/lower size tolerances can be set) or user-defined probe paths (which fit circles, cylinders and planes to give circularity, cylindricity and flatness; fit tolerances include position, upper/lower diameter, form, axis and normal). Tick Print Results to get a results file.

Inspect Surface (Manufacturing Extension)#

Uses a probe path to inspect complex freeform surfaces while the part is on the machine. Upper Tolerance and Lower Tolerance define the acceptable deviation band; points outside it are out of tolerance.

Part alignment and live part alignment (Manufacturing Extension)#

Use surface inspection results to calculate a part alignment for castings, forgings and near-net shapes; the live version imports results in real time over a live connection to the machine (a Machine Connector must be installed).

Manual inspection#

Create an inspection plan and record measurements directly in Fusion from calipers, micrometers or height gauges. PMI tolerances can be used for manual inspections and for Probe WCS and Probe Geometry operations.

Importing results and reports#

Results come from a machine-generated results file (common extensions include .mpf, .msr, .dat, .log, .a, .out, .bat and .txt, depending on the controller) or in real time through the Live Connection. You can save results as a PDF inspection report containing a title, a canvas snapshot, document name, units and tolerance legends.

Key options#

The macro call format depends on the post; Autodesk does not prescribe it.

Step by step: set X and Y from a bore#

1. Pick a probe from the Fusion Library Probes folder (or create one), with its tool number set.
2. In Manufacture, create or select a milling Setup.
3. Choose Inspection > Probing > Probe WCS.
4. On the Tool tab select the probe.
5. On Geometry, set Probe Mode to Model and click the bore face; pick the circular hole center Probe Type.
6. In the Actions/Settings tab tick Print Results if you want a results file.
7. Make it the first operation in the setup, before any cutting operation.
8. Generate and Simulate to check the probe positions.
9. Post using a probing-capable post for your controller and review the macro calls.

The machine touches the bore and updates the setup's WCS Offset; the rest of the program uses it.

Probing for rotary and multi-axis work#

Rotary-centre calibration and tilt measurement need macros beyond the Fusion topics checked here; consult your machine and post documentation.

Note: not confirmed in Autodesk's documentation: tool-setter measurement (tool length and diameter) and rotary-centre probing cycles. The Fusion topics checked describe Probe WCS, Probe Geometry, Inspect Surface, part alignment and manual inspection only.

Tips and pitfalls#

Tip: Probe as little as needed. Each touch costs time. Use the fewest touches that provide the information (a single surface for Z, a corner for X and Y).

Tip: Put probing operations in a separate folder or Setup and give them clear names ("Probe bore G54"), so they can be disabled for runs where the operator sets offsets manually.

Tip: Keep the probe's stylus short and rigid and recalibrate whenever it is changed (general practice).

Warning: An uncalibrated probe or a wrong probe tool length produces systematically wrong offsets. Calibrate on the machine and record the numbers.

Warning: Probing moves are slow but still move into material. A wrong feature location (wrong WCS or wrong model) can send the probe into a surface at rapid speed if not protected. Use probing macros that use the control's protected positioning (general practice).

Warning: Posts that do not support probing will ignore or mis-output the operations. Check the post notes and output.

Practice exercise#

On a simple plate with a 20 mm bore, add a probe tool to a library and create a Setup whose WCS is centered on the bore. Add a Probe WCS operation on the bore and a face-and-drill sequence after it. Simulate the sequence and post it with a generic Fanuc-style or your controller's post (if the post lacks probing support, note the warnings).

Expected result: the simulation shows the probe descending into the bore and touching four points before the cutting tool operations begin; the posted file shows probing macro or G31 move calls and an offset update before the first cutting tool change, or clear warnings if the generic post does not support them.

Related#

• WCS and orientation (what the probe is establishing)
• Post processing (probing macros)
• Tools and tool libraries (probe tool type)
• Fusion extensions for manufacturing