Reverse Engineering Components for Fit & Function

Reverse Engineering Components for Perfect Fit & Function

We combine exceptional technologies like CT scanning and modeling and inspection softwares to re-create perfect fit and function components. For example, these gaskets were worn and cracked and the client was unable to find replacement parts. Scanning just the casting or gaskets alone would not be adequate. 

Instead, we CT scanned all three components and virtually aligned them to ensure no critical design intent was missed.

3 2

Using Geomagic Design X’s silhouette cross sectioning feature allows us to model these gaskets using the full profile of a line even though the gaskets aren’t perfectly flat. We then use the center points of the casting to ensure bolts pass through with no interference. Then, we extrude the design cross section to the exact width of the gaskets.

Geometric Magnification Explained – 40um vs 8um CT Scan of Sensor

WHY RESOLUTION MATTERS

For x-ray & CT imaging there is a dynamic called Geometric Magnification. GeoMag (Mg) is the calculation of the distance between the x-ray source to test object and detector (Source to Object Distance, SOd) & (Source to Detector Distance, SDd).

If the detector remains stationary, the closer the object moves to the x-ray source the higher the resolution becomes. However, the further the object moves from the detector, the smaller the field of view. Put simply, the higher the resolution, the smaller the area of interest to be imaged.

A proper understanding of the project requirements determines the appropriate resolution and field of view. If a client needs to check for hairline fractures or micro-porosity, maximum resolution is necessary. If these defects are smaller than the resolution of the data they may not be resolved.

The below sensor is being scanned to evaluate potential leak paths in the soldered tip. The advantage of the 40um scan is that the entire part is characterized. However, the fine details of the area of interest are best resolved in an area of interest scan at 5x that resolution. At this resolution we can see micro-porosity not seen in the larger GeoMag scan.

40um Full Part Scan

8um Area of Interest Scan

X-Ray Repeatability of PCB Components

HIGH RESOLUTION X-RAY REPEATABILITY

High resolution x-ray is used to characterize PCB components for failure avoidance and analysis. With electrostatic discharge mechanisms in place, we image and sort safety and mission critical PCBs against customer specified metrics like porosity percentage, FOD size and location, bond wire straightness, general failure points, and many other indication types.

With programmable part manipulators and low density custom fixturing solutions, we guarantee the highest quality digital x-ray solutions.

The below image set is an example of our resolution, contrast, and positioning capabilities.

CAN YOU CAN SPOT THE FAILED SAMPLE?

Failure in the Field – Medical Instrument Carrier

Failure in the Field

This vessel is designed to hold and suspend implant screws in sterile liquid. The slots allow for various sizes to be carried using the same vessel. The vessel came to us because a screw was out of place inside the vessel prior to opening. Because of the occurrence the entire unit was quarantined for investigation.

The blue arrows point to a crack found in the seat of the carrier. The most probable explanation is that because some force is applied to hold the screw upright the seat cracked during loading. Then, during transit or handling the screw dislodged.

Versatility of CT Data

While this investigation was completed quickly, there is much more that can be learned from this dataset. For example, a common application for Industrial CT Scanning is seal and thread engagement analysis. This data can be exported to .STL for dimensional inspection, CAD comparison, and wall thickness calculations.

CAD comparison is useful to understand why the seat may have cracked. Perhaps the seat is accurate to CAD but the slots are out of position, causing stress fractures.

Pre-to-Post Use Evaluation using Industrial CT Scanning

High Resolution part evaluation

Industrial CT Scanning is used to characterize a variety of products including multi-material plastic assemblies like this wall anchor.

Some practical uses include:

> Fitment analysis - clearance & interference

>> Dimensional inspection - concentricity & wall thickness

>>> Porosity, inclusion, and fiber orientation evaluation

>>>> Pre-to-Post Use Comparison

Pre-to-Post Use Evaluation

Pre-to-Post use evaluation is particularly useful for understanding how a part changes over time. For example, in the below comparison slider we can see the threads created from a screw. We can measure the wall thickness where the expansion wings bend. We can also see how the the interface between the two components changes. Lastly, we can measure damage caused by insertion and removal.

Anchoer Close 1 Anchor Close 2

CT Scan of Shaver – Blade Wear Analysis

Evaluating an Electric Shaver

Industrial CT scanning can be used to investigate components and assemblies for proper part placement, failure analysis, and wear. This Norelco shaver is a great demonstration sample because of how complex it is:

Blade wear comparison

New and used blades were scanned at higher resolution to understand how the part changes and becomes less effective over time. First, the blades were aligned on top of each other for a direct visual comparison.

The top view shows a cylindrical unroll of the blade. This allows us to simultaneously view all nine blades. From this view we can hypothesize that the lower performance of the used blade is caused by the blades being bent downward over time.

measuring the hypothesis

By exporting the blades into .STL scan file format we can use PolyWorks dimensional software to produce a part to part profile comparison. This map confirms that most of the blades are approximately 50 microns lower than the new blade.

CROSS SECTION COMPARISON

A 2D cross-section is placed across “best-fit” aligned blades. The used blade was then manually shifted to the left to help visualize the samples. Then, arcs were defined on each blade with an approximate deviation of .006mm between nominal (new blade) to measured (used blade.)

CT Imaging NASA J2 Engine Thrust Chamber Cooling Channels

CT Imaging the Brazed Tubing of Saturn V J-2 engine Thrust Chamber

Per Wikipedia the J-2, commonly known as Rocketdyne J-2, was a liquid-fuel cryogenic rocket engine used on NASA’s Saturn IB and Saturn V launch vehicles.

The J-2’s thrust chamber assembly served as a mount for all engine components, and was composed of the thrust chamber body, injector and dome assembly, gimbal bearing assembly, and augmented spark igniter. The bell-shaped chamber was regeneratively cooled by the cryogenic fuel flowing through these tubes. The brazed tubes are aligned then melted together to form the chamber and bell which was tricky, expensive to manufacture, and prone to defective end results.

j-2-thrust-chamber-assembly-sm
j-2-thrust-chamber-detail-sm

The above chamber section was CT scanned (thousands of 2D x-rays about a 360 degree axis) at 225kv. The x-ray dataset was then processed into a 3D file, called a volume, where we scroll through and inspect the sample digitally. If only the engineers responsible for putting astronauts on the moon had the ability to inspect mission critical welds and joints in this way! Below we are able to characterize porosity, penetration percentage, wall thickness, and more.

Investigating Packaging Leaks using Industrial CT Scanning

PACKAGING inspection using INDUSTRIAL CT SCANNING

We regularly inspect packaging for a variety of goods using industrial radiography and CT scanning. Typical inspections include component presence verification, wall thickness evaluation, and leak path detection. This case study looks at a leaking boxed wine dispenser.

The dispenser itself is very interesting. The image below shows the functional sequence.

  • 1
    PRESS RUBBER BUTTON
  • 2
    BUTTON TRAVELS UP RAMP
  • 3
    RAISED BUTTON LIFTS RUBBER SEAL & COMPRESSES W-SHAPED SPRING
  • 4
    UPON RELEASE, W-SHAPED SPRING FORCES SEAL BACK TO CLOSED POSITION

Investigating Leak Point of Origin

  • 1
    PLASTIC BAG SEAL - BAG TO DISPENSER BONDED TOGETHER
  • 2
    CARDBOARD PACKAGING
  • 3
    UNROLL VIEWING LOCATION - USEFUL FOR VIEWING A CYLINDRICAL FEATURE IN A PLANAR VIEW
  • 4
    UNROLL VIEW - LEAK PATH - DEFECT OF INTEREST LOCATED