Five things to understand before buying a 3D scanner

3D scanning is for many people as fascinating as it is quite a mysterious process. A common perception of this is that with the help of a 3D scanner we “scan” an object or a figure, and the result of this activity is a ready 3D object that can, for example, be printed on a 3D printer on the spot. And that it is a relatively easy and simple operation, and the only barriers are the purchase of the device itself and its subsequent operation.

Meanwhile, as usual, the matter is much more complex – and interestingly, what seems to be the most difficult in all of this, paradoxically is the least of the problem … Here is a list of five things you should understand before buying a 3D scanner or commissioning a 3D scanning service to a specialized company.

3D scanning is not “3D photocopying”

3D scanning is a fairly complex process, where the geometry of the selected object is captured in space with the help of structured light or laser and digitally reproduced on a computer in dedicated software. The effect is the so-called “Point cloud” which, when connected to each other, create geometry that can be further processed in design or 3D modeling software.

In a way, you can say that the 3D scanner takes “3D shots” – it captures the fragments of an object that the software of the device intelligently combines with each other. Unfortunately, this is not a perfect process – while working, some things cannot be reproduced perfectly and come out distorted or completely deformed; deep holes are reproduced only to a certain extent – as precisely as the light or laser beam that the 3D scanner uses can reach there. Here and there there are also artifacts or noises that need to be manually removed at the software level.

Another thing is that the 3D scanner very accurately reproduces a given surface of the detail – even too accurately than we would like … For example – a few centimeters of steel or aluminum detail, which was made by casting method, will have irregular surfaces with numerous imperfections, invisible to the naked eye. A good 3D scanner will reproduce all this digitally, while our expectation was to obtain perfectly straight and smooth surfaces.

In summary, what we get from the 3D scanner is raw geometry that we need to continue working on in the CAD environment. A 3D scan is a kind of “semi-finished product” at the 3D design stage – on its basis, we only create the final 3D models in the design program. The 3D scanner is supposed to help us with this – not to do it for us.

Does this mean that you can’t produce anything right away from a raw 3D scan? It is possible, but the end result will be of much worse quality than the original. In fact, the effect will be the same as when copying photos on any xero – the copy will only be a substitute for the original and will never replace it.

2. The operation of the 3D scanner is relatively simple – everything else is difficult

Many people who do not have contact with 3D scanners fear them about the operation itself, while they are relatively simple devices. Regardless of whether we are dealing with a stationary or handheld 3D scanner, the biggest challenge will be to calibrate it – in some models it is relatively easy, in others it takes longer and is more complex. Nevertheless, as soon as we master it, the 3D scanning itself will not be too problematic.

Everything that is most difficult always starts at the level of a 3D design program, where we will have to tame the effects of our work with a 3D scanner.

3. There are various 3D scanners for 3D scanning of different things

Just as there are no 3D printers on which it would be possible to print any part of the same good quality, there is no universal 3D scanner with which you can “scan everything”. 3D scanners can be divided into three categories:

• for 3D scanning of small, precise parts (with dimensions up to 10-15 cm in XYZ axes)
• for 3D scanning of medium parts (with dimensions from several to several dozen centimeters in the XYZ axes)
• for 3D scanning of large infrastructure objects or vehicles.

The cheapest are the 3D scanners from the second group, the most expensive from the third group. Of course, this is a very conventional division aimed at people who are just taking their first steps in the world of 3D scanning. On the market we can successfully find super-precise 3D scanners for 3D scanning of small parts with an accuracy of single micrometers, costing as much as 3-4 high-class large-format 3D scanners – this is the basic principle – if we want to scan “some small things and some such medium ”, we need to equip ourselves with two devices. Unfortunately, there are no universal solutions and “budget options”. Just like there are no super durable off-road cars that “burn little in the city” …

4. A good 3D scanner has good 3D scanning software, but that is not enough for the complete process of reproducing things

Good 3D scanner software is characterized by the fact that the individual 3D scans connect with each other in a fairly intelligent way, limiting the operator’s interference to an absolute minimum. They also allow for easy and simple reduction of artifacts and noise from the space surrounding the scanned object. In other words – a good 3D scanning program allows you to easily and quickly 3D scan. Unfortunately, independent programs are necessary for further work …

If you want to replicate parts or recreate them for the purposes of modification and design changes, you need dedicated CAD-class software or 3D modeling (sculpting). It can be one of the most popular tools in the world: Autodesk Fusion, Inventor, Solidedge, Solidworks, Catia, Creo, Rhino3D, ZW3D etc. etc. – it is only important that it allows you to work with 3D objects.

Unfortunately, each 3D design program has two quite significant drawbacks:

• it is expensive (from several thousand EUR up)
• it must be learned to use (which may take several weeks upwards).

Therefore, the purchase of a 3D scanner itself is only a certain investment stage in the entire process of digital reproduction of parts – it may turn out that we will have to spend comparable money on 3D software as on the device itself. What about free programs such as Blender? You can try to use them, but despite the really numerous functionalities under the “free price”, they are not applications dedicated to this type of work.

5. What about the computer and the rest of the 3D scanning accessories?

People planning to buy a 3D scanner are often not aware that, apart from the device and software itself, they will have to stock up on a number of other quite important things in later work. The basic one is a computer on which we will be able to easily process and modify 3D scans.

The entry threshold is a machine with min. 16GB of RAM and an independent graphics card. In the laptop area, the best options are gaming laptops, which should be able to handle files weighing from several hundred megabytes – several gigabytes each. In the area of ​​desktop computers, it is worth designing the right workstation together with the supplier of the 3D scanner. Anyway, we have to take into account the expense of min. several to several thousand zlotys.

If we buy a handheld 3D scanner, it is worth getting a dedicated transport box and considering the purchase of a tripod and a rotary table, which will also allow us to scan stationary. If we are considering purchasing a 3D scanner for structural light, we should obtain markers – stickers that we will stick to the scanned objects in order to calibrate the 3D scanner and find it in space, and sprays to cover reflective or transparent surfaces.

If we buy a large-format scanner for outdoor work, we should obtain additional batteries, better stands, accessories for faster calibration of the device at the destination and … a tent that will protect our equipment from rain.

In summary, the cost of purchasing a 3D scanner includes:

• the 3D scanner itself
• accessories depending on the type of 3D scanner and the specifics of the work we will be doing with it
  3D design software
• computer.