FreeProbe 2 for Hidden-Feature Inspection

A surface scan can show the entire visible skin of a casting or welded assembly and still miss the feature that controls acceptance. Deep bores, recessed slots, hidden datum points, and obstructed edges may be inaccessible to the scanner even when the surrounding mesh is complete.

FreeProbe 2 and FreeProbe 2 Pro add tracked contact measurement to compatible FreeScan Trak systems. The useful question is not whether probing is better than scanning. It is which features need dense non-contact data, which need discrete contact points, and how both results will be qualified in one inspection plan.

When does FreeProbe 2 fit a hidden-feature inspection workflow?

FreeProbe 2 fits when a compatible FreeScan Trak system can capture exposed surfaces but the inspection also needs physical points inside bores, slots, recesses, or partially obstructed features. It is most useful when the same tracked coordinate system must connect full-field surface data with discrete contact measurements on a large part.

FreeProbe is not a standalone coordinate measuring machine. SHINING 3D lists compatibility with FreeScan Trak Nova and FreeScan Trak ProW. The tracker observes the probe, while the qualified stylus contacts the feature. That architecture lets an inspection team select the appropriate sensor for each characteristic without moving the part between unrelated coordinate systems.

• Use surface scanning for shape, trim, weld profiles, broad deviation maps, and accessible geometry.
• Use contact probing for hidden points, defined bores, deep recesses, datums, edges, and features that the scanner cannot see reliably.
• Use another method when the required uncertainty, access, material behavior, or acceptance rule is not supported by the tracked workflow.

Review the FreeProbe product page for current United States configurations and pricing. The selection should begin with the drawing characteristics, tolerance, part size, access, environment, reporting software, and the tracker already in the measurement plan.

How do surface scanning and touch probing work together?

The scanner first establishes dense visible geometry, and the tracked probe then acquires selected contact points where optical capture is incomplete or unsuitable. Both sensors must be controlled within the approved tracker setup, alignment, software, and inspection sequence. Combining data does not remove the need to qualify each measured characteristic.

A practical sequence starts with the measurement plan, not the hardware. Identify every characteristic and assign the intended sensor. Capture and optimize the accessible surface mesh, maintain the approved coordinate relationship, then use the probe for the remaining features. SHINING 3D documents workflows in which the mesh is imported into supported inspection software before probe points or measured features are added.

The adjacent FreeScan Trak ProW large-casting inspection workflow covers the surface-capture path. FreeProbe extends that path for inaccessible discrete features; it does not convert every scanned characteristic into a contact measurement.

What does the published 0.025 mm FreeProbe accuracy mean?

SHINING 3D publishes 0.025 mm accuracy for the FreeProbe series, but that value is not a blanket guarantee for every feature, part size, tracker volume, stylus, environment, or reporting decision. The inspection team must evaluate the complete system and the uncertainty of the actual measurement result.

The official FreeProbe page also publishes tracker-specific volumetric performance and extension formulas. Those values depend on the selected FreeScan Trak system and measurement volume. Do not compare the 0.025 mm probe figure directly with a drawing tolerance without accounting for tracker geometry, probe qualification, feature extraction, alignment, environmental effects, and the decision rule used to accept or reject the part.

SHINING 3D states that the FreeProbe series is ISO 10360 certified and tested in an ISO/IEC 17025 accredited laboratory. That is useful evidence for system evaluation, but the buyer should still request the current documentation for the exact configured system and confirm how it applies to the planned measurement.

How should a team choose between FreeProbe 2 and FreeProbe 2 Pro?

Choose by access, reach, visibility, operating time, and the tracker configuration, not by the Pro label alone. FreeProbe 2 is the lighter option; FreeProbe 2 Pro is longer, supports deeper probing, and is designed to retain tracking when some marker plates are partially blocked. Validate both against the real feature layout.

SHINING 3D publishes a weight of 0.46 kg for FreeProbe 2 and 0.59 kg for FreeProbe 2 Pro. The published body dimensions are 50 x 110 x 363 mm for FreeProbe 2 and 50 x 113.5 x 454.5 mm for FreeProbe 2 Pro. The longer body can improve access, but it can also change operator clearance and handling around fixtures.

FreeProbe 2 uses two rechargeable batteries with a published operating time of up to 16 hours. FreeProbe 2 Pro is published at up to 80 hours. Battery endurance matters only after the team has confirmed feature access, line of sight, stylus geometry, software compatibility, and the uncertainty required by the measurement plan.

Which probe-tip and calibration controls protect the result?

Qualify the exact stylus geometry, calibrate it in the approved tracker setup, and recalibrate after a probe-tip change. SHINING 3D also calls for calibration when the probe has not been used for an extended period or when accuracy has declined. Record the probe, tip, calibration status, software, and operator with the result.

SHINING 3D documentation supports vertical and L-type probes, tip diameters from 0.3 to 10 mm, vertical lengths from 1 to 200 mm, and defined or custom L-type dimensions. Access alone does not make a tip suitable. Consider ball diameter, shaft interference, probing direction, feature depth, contact force, surface condition, and whether the software extracts the intended geometric feature.

How do tracker visibility and the shop environment affect probing?

The tracker must maintain the required view of the probe, and the probe tip must remain within the supported camera range and geometry. Fixtures, operators, part walls, glare, vibration, temperature change, and an unstable tracker position can all affect the measurement chain. Plan visibility before the part reaches final inspection.

FreeProbe can connect wirelessly or by cable, but only one probe is connected at a time in the documented workflow. A wireless connection can reduce cable interference around a large assembly; it does not solve occlusion. Rehearse the tracker and operator positions for every critical feature, especially where deep access or nearby walls restrict the probe orientation.

For broader system selection, compare the SHINING 3D industrial scanner portfolio by inspection role and verify which tracker, scanner, probe, workstation, software, and training components belong in the configured package.

How should a United States inspection team qualify the workflow?

Define the measurand, drawing requirement, sensor, alignment, sampling strategy, environmental limits, calibration evidence, uncertainty, and acceptance rule before collecting production results. Then run a measurement-system study on representative parts and operators. Traceability, repeatability, and fitness for the tolerance must be demonstrated for each important result.

1. List the characteristics and assign surface scanning, touch probing, or another method to each one.
2. Define the tracker location, measurement volume, probe access, fixture, coordinate system, and datum strategy.
3. Qualify the probe tip and record calibration status before the run.
4. Measure representative features across operators, days, positions, and expected environmental conditions.
5. Evaluate bias, repeatability, reproducibility, alignment sensitivity, and software feature construction.
6. Set an acceptance rule that accounts for measurement uncertainty and the consequence of a wrong decision.

NIST explains that metrological traceability is a property of a measurement result, supported by a documented unbroken calibration chain in which each link contributes to uncertainty. Traceability alone does not prove that the result is fit for the inspection decision.

The ASME B89 dimensional-metrology program includes standards covering dimensional measurement planning, decision rules, measurement uncertainty, and traceability. Apply the requirements and customer-specific controls that govern the actual United States contract, product, and quality system.

When is a fixed CMM, portable arm, gage, or another method safer?

Use another method when the required uncertainty margin is too small, the probe cannot maintain access or tracking, the part or fixture moves unpredictably, the environment cannot be controlled, or the customer mandates a different method. A dedicated gage or fixed CMM may also be better for repetitive high-volume characteristics.

FreeProbe is valuable when flexibility and large-part access justify a tracked probe-and-scan workflow. It should not be forced into every characteristic. A fixed CMM can provide a more controlled environment for tight, repeatable features. A portable arm can fit a different access pattern. A functional gage may be faster for a repeated production decision. The measurement plan should make that choice explicitly.

The industrial 3D scanning and inspection workflow guide provides the wider decision path for surface inspection, quality control, CAD comparison, and advanced requirements.

Where can the technical claims be verified?

The specifications and operating controls in this guide are grounded in current SHINING 3D FreeProbe documentation. Measurement-planning, uncertainty, traceability, and decision-rule context comes from NIST and ASME resources. Confirm the latest manufacturer documents, configured system, software version, and contract requirements before approving a production inspection method.

• SHINING 3D: FreeProbe Series features, specifications, compatibility, and certification statements
• SHINING 3D: FreeProbe setup, calibration, probe-tip, and inspection-software workflow
• NIST: Metrological Traceability policy and FAQ
• NIST: Measurement uncertainty considerations for coordinate measuring machines
• ASME: B89 dimensional metrology standards overview

Technical review: SKYLAB3D Engineering Team. Published accuracy is configuration- and condition-dependent. Qualify the complete measurement process for the exact feature, tolerance, environment, software, and acceptance decision.