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From clay to a motorcycle…

From clay to a motorcycle…

I remember playing with clay back in the days, in visual art class. I remember trying to make a vase… it sure was not easy. I never imagined that there was a much deeper use for clay, one that would still widely be used 25 years later. I am talking of course about the subtle art of designing vehicles with clay.

Designing bodywork for a specific vehicle is delicate and precise work. It requires a lot of experience and know how. Given how impactful every tiniest detail is, it is essential to use the most accurate tools possible and, for most designers, these tools are… their hands!

Take the example of Nick Graveley, a senior designer at claymoto. When working on a new project, he usually starts with existing components such as the frame or even the entire motorcycle. That is one of the first step where 3D scanning comes in handy and where Nick will use his peel 3d scanner. An accurate scan of the existing bike will be quite helpful later in the design process when designing the actual body parts. Peel 3d also provides all the necessary tools to convert his 3D scan into an accurate and reliable CAD model.

After a few hand drawn sketches, Nick starts to work with clay and puts all his skills to work shaping and designing what will be the perfect shape for the bike. After all, the body is most of what you see when looking at a bike, it is worth putting in the extra efforts.

Once the shape is perfect, Nick can put his peel 3d scanner to work again and digitize the shape he has just designed. 3D scanning really is the best way to bring your exact design into CAD and use it to design body parts. As soon as the scan is complete, the project of designing the actual parts can start and since everything has been modeled so accurately, the designer can be in great confidence that everything will fit the first time. Click the photo below to see Nick’s project in details.

 For more amazing design projects, follow Nick claymoto on IG.

Why should you pay more for a professional 3D scanner?

Why should you pay more for a professional 3D scanner?

You made up your mind and decided that 3D scanning was what you needed for your application. That’s a good start! It’s now time to choose which solution is most adapted to your needs. Shopping around, you may be tempted to consider more affordable 3D scanners. A lot of users online are promoting that there are some “very good” scanners available for $500-$600. Why would you even consider equipment that is 10x the price? Here are a few things to keep in mind when selecting a 3D scanning solution.

It’s all about the details!

Although Kinect-like 3D scanners usually have impressive capabilities when it comes to capturing data, they are rather limited when it comes to resolution (the amount of detail they will capture). Scanned objects and surfaces will often look quite smoothed out with round edges:

Transmission casing scanned with peel 3dTransmission casing scanned with  Skanect

Figure 1: Transmission casing scanned with peel 3d (top) and with Skanect (bottom)
More resolution means a crispier, more realistic scan where smaller features will be more precisely defined and more usable.


Is it accurate?

Even if a 3D scan looks nice, one should also consider how close it is to the actual model. The quality of the internal components, combined with software calibration, will have dramatic impact on the accuracy you can reach. Important errors are more than common on a low-cost scanner as can be seen in the below chart:
Accuracy comparison between peel 3d and Skanect
Chart 1: Accuracy comparison between peel 3d and Skanect
In this test, we scanned a controlled artifact 5 times with each 3D scanner, extracted the reference distance (point-to-point distance between two spheres), and compared it to the controlled measurement. As can be seen above, a Skanect 3D scanner resulted in an average error of 10.7 mm, while peel 3d provided an average error of 0.115 mm. The standard deviation is also significantly smaller with the peel 3d scanner.
This basically means that even if a shape is recognizable when scanned with a Skanect, it can be way off when if comes to how close it is to the actual object. In other words, if you are trying to design something based on your scan, chances are it will not fit (or be very loose).

Like aiming with a loose cannon!

There is also the notion of how repeatable an error is. Some measurement devices will not necessarily be accurate but at least afford good repeatability. For instance, think of a system that would provide an incorrect scale factor in a very consistent manner. All measures would be off—but always by the same amount (more or less). It’s not great but at least it can be compensated in some way…
Unfortunately, this is not the case of low-end scanners, especially when it comes to complex shapes, as can be seen below. The error is randomly spread over the scanned model in an inconsistent pattern:

Measurement error on 3 scan sessions made with a Skanect scannerMeasurement error on 3 scan sessions made with a Skanect scannerMeasurement error on 3 scan sessions made with a Skanect scanner

Figure 2: Measurement error on 3 scan sessions made with a Skanect scanner (warmer colours = positive errors, cooler colours = negative errors)

In this test, we compared the scan results made with a Skanect on a controlled mannequin head. As can be seen, despite following consistent measurement technique, the errors were significant and random, sometimes exceeding and sometimes short of the reference shape by several mm.

This basically means that your different scans will have significant measurement differences from one scan to another—even if you scan the same object, with the same technique and in the same environment! The results you get will basically be random within an important range.

Things you can do with your data…

Using a 3D scanner also usually involves at least a few post-treatment steps. For instance, you will likely need to remove surrounding surfaces (to isolate your object). Moreover, you will likely need to fill areas you couldn’t scan, re-align and perform your scan again, etc. The tools included in very affordable 3D scanners are usually quite limited, rudimentary and rather unstable.

Data finalization is essentially to 3D scanning what putting is to golf; it’s half the game and you can’t really neglect one vs the other. This means that if you plan to use your low-cost 3D scanning data, chances are you will need to invest in additional software (i.e. add significant cost to your solution).

Almighty targets!

Finally, trying to scan something flat or smooth (a car door for instance) will certainly be very challenging with low-cost scanners as they generally only rely on geometry for positioning; these items barely provide any geometry information to grab onto. This means you might wind up with very poor-quality (even unusable) results.

Stick-on markers will on the other hand ensure the accuracy of your 3D scanner and let you accurately scan the flat or smooth surface, making it fully usable in your application!

In the end…

Low-cost 3D scanners are not bad at all: they are actually a nice place to start with and get familiar with 3D scanning. If you are a hobbyist and interested in starting 3D scanning for fun, this could be a good place to start with. Affordable scanners may even be suitable for your specific application. However, if you are working in a professional environment, on commercial applications, a professional and comprehensive 3D scanning solution is best.