Every detail counts:
A functional object can become a beautiful moment”
The eT-pen
PURPOSEFULLY DESIGNED
PURPOSEFULly dESIGNED
Every detail counts: A functional object can become a beautiful moment”
—Sarah Bartholomew
t
he perfect stylus doesn’t exist. The writing experience is a very subjective feeling, which depends on several factors including the physical attributes of the pen, but also the individual traits of the writer. Although it is impossible to take all these aspects into account in a single pen, what we can do is try to reach a compromise between as many of these factors as possible –balancing contrasts gives birth to a functional object!
Our design philosophy originates in the concept of functionality: Our stylus should be useful, practical, and rightly designed for its purpose. We wanted a stylus suited with a specific aim: to serve the Boox Note Air. Thus, it had to magnetically attach to the tablet, but it also had to reflect the slim and colorful aesthetics of the Note Air. At the same time, our stylus needed to be chiefly designed to be of practical use: it should include an eraser button and should be compatible with a wide range of different tips. Apart from its appearance and functionality, we also wanted our stylus to be easy to hold and to feel natural in hands.
The first 3D-model of our stylus materialized in the design of Figure 1. Just like the Note Air, the idea was for the body to be predominantly blue with some orange stripes. We wanted a simple and delicate body matching the slim character of the Note Air. This model quickly encountered several challenges, which helped us to consider the ways we use and abuse the stylus. It also led us to rethink its appearance and function, and how it expresses our wishes.
The design process can be quite frustrating usually taking various tries to get the “right” design. Every attempt is an opportunity to conceptualize and evaluate ideas. Numerous prototypes helped us to assess the writing experience, to evaluate the magnetic adherence, to challenge the designs, to identify drawbacks, and to propose alternatives. This is how the eT-pen was finally conceived.
General Specifications
We wanted our design to be primarily compatible with our magnetic adherence system. Therefore, instead of favoring an unconventional “ergonomic” model, we opted for the traditional round shape in section. We set the diameter of the eT-pen to approx. 8.45mm. This is explained by our desire to have a slim pen reflecting the slender character of the Note Air, while providing enough grip to comfortably hold the stylus. Our objective was to reach a compromise between grip, thinness, and weight.
Table 1 compares the diameters of several popular styli.[1] The midrange between the minimum and maximum diameters in Table 1 is 8.85mm. A similar measurement (8.81mm) is also obtained when we consider the average diameter instead. This may be seen as an equitable balance between those who feel comfortable with a slim pen and those who prefer more grip. However, our diameter is still 0.4mm below this measurement. What explains this difference? Well,
on the one hand, an 8.85mm diameter is 2.85mm ticker than the Note Air. By setting the diameter to 8.45mm instead, we decrease this gap by 14%. This is a significant reduction considering that we have narrowed the diameter by only 4.5%.
Table 1 compares the diameters of several popular styli.[1] The midrange between the minimum and maximum diameters in Table 1 is 8.85mm. A similar measurement (8.81mm) is also obtained when we consider the average diameter instead. This may be seen as an equitable balance between those who feel comfortable with a slim pen and those who prefer more grip. However, our diameter is still 0.4mm below this measurement. What explains this difference? Well, on the one hand, an 8.85mm diameter is 2.85mm ticker than the Note Air. By setting the diameter to 8.45mm instead, we decrease this gap by 14%. This is a significant reduction considering that we have narrowed the diameter by only 4.5%.
[1] Data presented in Tables 1 to 3 is based on actual measurements. Thus, this information may slightly differ from the one provided by the corresponding manufacturer.
On the other hand, we also wanted the eT-Pen to achieve a balance between the weights of the different styli in Table 2. The midrange between the minimum and maximum weights in Table 2 is 10.25g. In contrast, the average weight is 9.62g. With a diameter of 8.45mm, our stylus weighs 10g, which we believe is a reasonable compromise between the previous two measures. If the diameter is enlarged to 8.85mm, the weight of the stylus would have exceeded 10.25g.
The total length of the eT-Pen is 165mm. Our pen is considerably longer than most of the popular styli used by the Boox community. For a comparison, look at Table 3. The length of the eT-Pen was defined according to the length of our shaft, which in turn was determined by the number of magnets. We evaluated the magnetic adherence of various prototype versions of our shaft to finally conclude that the optimal number of magnets was four: Five magnets would enlarge the length of the pen too much, while three magnets would not represent a significant improvement over the S-pen.
The Barrel
One important feature of the barrel is the shape of its magnetic face. Unlike the Boox pen or the S-pen, which have a flat magnetic side, we have implemented a grooved magnetic face that perfectly adopts the shape of the Note Air’s curved edge contour. In Figure 2 we illustrate the section view of the barrel. A grooved magnetic side has the advantage of maximizing the surface contact between the pen and the tablet, ensuring better magnetic adhesion.
In addition, we wanted to add a touch of elegance to our design by making the magnetic groove blended harmoniously in with a continuum of narrower grooves starting from the cap and extending towards the nib with dissymmetrical lengths (see Figure 3).
The Cap
To restore the delicate chromatic balance that characterizes the Note Air, we decided to give an orange color to both the cap and the eraser button.
The cap is characterized by a flat surface that cuts the top of the barrel at an oblique angle (see Figure 4). In this way the cap blends in with the barrel following the same grooved pattern. In addition, the name of the pen is embossed in high relief following an entanglement of the initials ‘e’ and ‘T’.
Technical specifications
Like most of the electronic circuits in the world, the printed circuit board (PCB) of our stylus was produced by a PCB manufacturer in China, and it follows the standard functioning of the S-pen. Thus, it supports 4.096 level of pressure sensitivity and is equipped with an eraser button. We also wanted our pen to support tilt detection, since we are also regular users of the reMarkable tablet. Unfortunately, this feature will not be useful for the utilization with the Note Air.
On the other hand, the eT-pen is compatible with various tips including those of Onyx Boox, reMarkable, Lamy, and Samsung.
Creating our stylus has been an iterative process: first, an idea conceptualizes in a 3D design, then the resulting model materializes in a tangible 3D-printed object. This prototype is tested, drawbacks are identified, the design is challenged, and alternative ideas are proposed. The previous steps repeated over and over until we were able to validate our final design. This creative process defines how our stylus has evolved from its initial conception to its final materialization. In this sense, it gives our stylus a personality of its own.
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Thank you very much for your interest in this adventure, we love to have you on board!
Audrey & Andrés
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