Sep 03

NanoCT of woven material

This example shows a small section of material scanned using nanoCT and analyzed for fibre thickness and angular distribution

Very short video of the CT slices: fibres

Sep 03

NanoCT of cardboard

One application of nanoCT scanning is to measure coating thickness of paint coatings for example. In this case a cardboard packaging material has its paint coating analyzed with a colourmap showing the thickness distribution.

This is the 4 mm sample loaded for a scan

Coating thickness analysis



Sep 03

Flower for Womens day

It was women’s day recently in South Africa so we scanned a flower and made a digital colourful mesh, which you can open in any CAD program or even windows10 can open it in 3D. Find the files on thingiverse here:

Also see the video here and send someone a digital flower : FLOWER

Sep 03

Full volume tetrahedral mesh from microCT data

This video shows the generation of a tetrahedral mesh from a microCT scan – tetmesh_small

This is a new functionality in Volume Graphics VGSTUDIO MAX 3.3. We can do this for you with any 3D data. See more at for this and other 3D image analysis services. This example is a tensile dogbone sample in cast Ti6Al4V, with large casting pores in the middle. Previous work on this topic using direct voxel-based simulation can be read here: Enjoy the video! StellenboschCTfacility microCT simulation 3Dmesh

Aug 30

Nautilus nanoCT

A nautilus shell is analyzed here using a nanoCT scan and 3D image analysis powered by VGSTUDIO MAX.

For more about this interesting natural structure have a look at wikipedia here, the analysis is meant to show how nanoCT can visualize and analyze interesting structures in full 3D, as in the video and images below.

VIDEO MP4 file: nautilus video_smaller

Jul 29

Artec Eva and Spider handheld scanners available for rental

Good news for hands-on students and engineers – we are renting out our Artec Eva and Artec Spider scanners on daily, monthly and annual rates. Do your own scanning, with the best handheld scanners around.

Examples of scans can be found here:

Specs of scanners:

International clients welcome, on long term rentals Artec 3Dscanning reverseengineering

Pricing as follows for both scanners together (daily, monthly, annual rates in that order, excluding 7% admin fee and 15% VAT):

Academics & students: R1000 per day, R10 000 per month, R100 000 per year

Industry: R2000 per day, R20 000 per month, R200 000 per year

Minus 25% from above prices for only one scanner at a time

Jun 28

Coffee bean nanoCT scans

This study in collaboration with Dr Karen Cloete from iThemba Labs includes some great coffee bean images and a great video can also be seen here. Find the full paper here:

And a great video here:

coffee bean v2


Apr 16

International CT scans

This case study is meant to explain that our CT scan services are international – there is no need to be here on location for scanning and shipping most typical samples are no problem at all. The advantage? The price! The price of CT scans is much lower here than in your local CT service lab. So to make a case study of this we scanned a South African 2 Rand coin and a 2 Euro coin, as well as my credit card. All images here are from CT scans – and imaged using VGSTUDIO MAX 3.2. No coins or credit cards where harmed in the making of this case study (totally non-destructive process).

First up – the Euro (video here – Euro video):

Now for the South African Rand (video here 2 Rand):

Now, we take apart the Euro (video here euro take apart):

For viewing the Euro and Rand side by side – see this video  Euro and Rand

Comparing the Rand to the Euro – clearly the Euro is thicker:

And overlapping them – it seems there are mostly major deviations between Euro and Rand.

So can you pay by credit card? yes you can. Here is an example of a X-ray of a credit card with chip (and small crack in plastic):

Also see the CT scan of the chip in this video and image below: credit Card Chip Wall Thickness


We hope you enjoyed this case study. On a more serious note – if you know microCT scanning and want to send us your parts you are welcome – we offer international CT scan and analysis services on hourly rates of $165 (US). If you are unsure please see the “make an order” tab or contact us to make you a quote. For international shipments, please add clearly to the package “for testing only – nominal value $1” to ensure no delays and simplify the process, and please use dedicated courier services (e.g. DHL), not postal services.

Apr 10

CT scanning of cast metal parts

This is one of the best-known applications of X-ray inspection and CT scanning – to check cast metal parts for porosity and extent of porosity. Here one example with nice video showing the data and results available for such parts.


Mar 18

X-ray CT inspection for medical implants


This case study was performed to demonstrate how routine X-ray CT inspection adds value to medical implant production, ensuring quality and reliability. This particular case is for 3D printed (additively manufactured) titanium hip and knee implants but the methodology is applicable to all manufacturing techniques, not only additively manufactured implants.

X-ray CT inspection is relatively expensive compared to older inspection methods, but is significantly better as it allows entirely new insights and streamlined workflows, saving costs long-term and providing higher reliability in inspections – which is ultimately better for the patient. This case study aims to show that the costs are not excessive, and is based on current costs for CT inspection services at the Stellenbosch CT facility, which is a relatively low-cost service facility compared to international X-ray CT inspection services. This is an example of a relatively routine inspection – for special cases such as higher resolution requirements, denser metals, or specialized scan parameters, the costs can be higher. In some cases costs can be lowered for simpler inspections, simple samples and easy-to-detect features. This case study is a typical workflow and a good indication of costs – especially for new users of the technology.

Implant samples

Two samples were provided by Executive Engineering (, who produce these parts under contract for LRS implants ( Both these companies gave approval for the release of this case study. Executive Engineering is a local company on the outskirts of Cape Town which has a newly established metal additive manufacturing facility, with an EOS M290 currently running only Ti6Al4V. LRS implants specialize in design and production of custom medical implants.

The two parts are biomedical titanium alloy Ti6Al4V (ELI) material and are parts of hip and knee joint implants. They are shown in Figure 1. Lattice regions are included to improve long term bone-in-growth and attachment. Both parts were scanned at typical parameters used for this material, at resolution defined by the sample size. For more on scan parameters and optimization, please refer to the references or contact us for more information.

Figure 1: The implants – photograph with magazine for scale and 3D X-ray CT images


What results do we get?

X-ray CT is a technique that has many capabilities – it can be used for many things. Obviously when you want to do everything – it costs the most. We break it down into different levels, you might only want one of these, but we demo everything here. The first level, which could be called manual CT inspection, is the simplest and lowest cost. This involves simply checking the part in virtual cross section images (called CT slice images). After scanning and basic data handling, the inspection is done by viewing cross-sectional images. This can be done by the user himself, requires no complex software tools and easily and clearly visualizes even small internal flaws which might be problematic. An even simpler way to do this is to view a slice video, see here for videos of both implants – also shown in Figure 2 in different slice views of both implants. In these images, everything in the white line (all white and grey areas) is metal, and black is air. In this part no unexpected cracks or flaws were found. For examples of porosity, cracks or flaws please see this case study of a few years back – for a cast metal part. Major flaws would be in the form of dark black areas and lines in the white material, which are not present here.

Figure 2: CT slice images showing no internal flaws – the inserts show the location of the virtual slice


Video of all slices from top to bottom – implant 1: slice video implant1 HD


Video of all slices from top to bottom – implant 2: slice video implant2 HD


Manual inspection requires a scan of high quality, and basic data handling to generate clear well-contrasted slice images. Usually we the CT service provider highlights “indications” – areas of potential flaws. This can also be handled by the customer himself, either with slice image stacks, video or full data with free 3D viewer program. This program is called Volume Graphics myVGL and is freely available for all data handled by Volume Graphics VGSTUDIO MAX 3.2, which is also the software used for this case study. Videos on how to use this is available here. For the scan + basic data handling, the cost is R2900 (international rate US$330). This provides clear insight into the presence of flaws and is suitable for all parts (as the method is entirely non-destructive) or can be applied to selected samples from batches produced under identical conditions. This price is applicable to decent quality scans without special requirements, i.e. it is for typical implants of light metals, in the range roughly 50 – 150 mm in longest axis. Smaller or larger samples might require some variation of scan protocols which adds to the cost.

Besides using this method for checking to ensure all parts are flawless (and reject those that aren’t), it is also possible to use the method for calibration of systems and production process checking – using smaller test parts. This provides a fixed, documented result of the same test geometry analyzed the same way over time. This allows insight into the production quality and any progressive quality issues developing over a longer term. This is a topic which is highly applicable to all forms of manufacturing, but is especially useful for additive manufacturing where many factors can affect the quality of the final product.

A quantitative defect analysis function allows colour coding of pores inside the part, when this is found. This is an extra R1450 (international $165), but in this case no such flaws where found. This method is particularly useful when testing small coupon samples for optimizing the production process, ie. when improper settings cause some porosity or flaws. The advantage of a quantitative 3D colour coding of defects is the ability to understand the 3D shape and distribution of the flaws relative to the part features (e.g. near critical areas, or showing what the cause of the problem is, to more easily and faster fix this problem).

For this case study, the next level of insight is the use of the same scan data for metrology – that means accurate dimensional measurement, often done traditionally with coordinate measurement machines (CMMs). The accurate surface determination allows various selected dimensional measurements such as diameter of critical cylindrical cavities shown for the part in Figure 3. In addition the STL file data can be exported, or preset dimensional analysis can be performed on batches of parts with accept/reject criteria. For typical CMM measurements of up to 10 features, the additional cost is R1450 ($165 international). For batches of similar parts more measurements can be preset and run automatically for the same price.

Figure 3: X-ray CT is also a coordinate measurement machine, without limits on complex geometry or accessible points

The next level, also costing the same (R1450 or international clients $165), is comparing the actual produced part with its CAD design file, to see where large deviations occur. The implant is shown in Figure 4, with most of the part within 0.3 mm. The scan resolution here was 65 µm – and with good scan data up to 1/10th the voxel resolution can be used as the accuracy of the surface values. This means the surface data is likely 6.5 µm accurate, without any limits on hidden or complex features, or limits on surface finish which are sometimes issues with CMMs.

Figure 4: CAD variance analysis – showing most of the part is within 0.3 mm of the design file.

A useful additional tool is wall thickness analysis (you guessed it – additional R1450 or $165) – this method shows the thickness of walls of the part, mostly used for checking traditionally designed parts with parallel walls. It can also be used to visualize and check the thickness of very thin and complex areas such as lattice structures, as shown in Figure 5. Here most of the lattice is within 0.2-0.5 mm thick. The method used here is the sphere-method – the largest sphere that fits in the material at each point is reported as the wall thickness at that location.

Figure 5: Wall thickness analysis applied to lattice areas showing local thickness of struts


So what are the limits and how to overcome them?

As with all methods, there are some limits. When materials unexpectedly contain high levels of dense inclusions or materials containing X-ray dense materials, this causes unwanted image streaks which make some analysis methods impossible. Often the presence of steel screws in parts with lighter metals have the same effect. Sample size is limited, and this is especially important when looking for small flaws – i.e. when there is a small flaw or crack and the resolution is not good enough, these may be missed. These and many other possible issues may lead to failed or inconclusive results. Some key points to ensure high quality CT inspections:

  • Smaller samples provide better quality and resolution
  • Scanning two or more parts at once provides worse quality and resolution
  • Remove all screws or unnecessary material from the object of interest
  • Understand the limits and the capabilities to get the most from the technique



Clearly X-ray CT inspection is a powerful tool for entirely non-destructive inspection of medical implants. We have demonstrated here the following levels of inspection, which are possible:

Description Cost

* Excludes 7% admin fee and VAT

1 Manual CT slice inspection R2900 / $330
2 Defect analysis (quantitative) +R1450 / $165 (optional)
3 Coordinate measurements +R1450 / $165 (optional)
4 CAD variance +R1450 / $165 (optional)
5 Wall thickness +R1450 / $165 (optional)


This means that for one part, for an all-inclusive analysis of everything possible, it costs less than R10 000*. While this is more than traditional nondestructive testing (NDT) tools, the clarity and quantitative assessment allows to really improve the lives of patients, to clearly identify when even small flaws or manufacturing errors are found in parts. On the other hand, even the first-level of analysis is useful for this purpose, bringing the cost down by almost 70%. Further cost reduction might be in optimizing and calibrating the production process itself using CT on a regular basis and not inspecting all parts produced. Any way you look at it, the insight into implants with 3D X-rays is clearly value for money. If you are not yet convinced, have a look at this video which summarizes all the above: medical implant scan small_version


This case study was made possible with cooperation from Executive Engineering & LRS implants. Scans were performed at Stellenbosch CT facility and visualization and analysis performed with VGSTUDIO MAX 3.2.