01. Project Info
More than just a tool
Finding the right drilling depth for your dowels to fit in perfectly can be a frustrating and time – consuming task. Either the hole is not deep enough and needs redrilling, or you have already gone too far.
This new Skil drill with Smart Drill-Assist technology lets you set your desired drilling depth, and will automatically stop when this depth is reached by measuring the difference in distance between the drill and the object.
This project was done for Skil which eventually bought the intellectual property for this product.

02. The Process
More than just a tool
In this project, the main focus was on development and testing of prototypes. Among others, visual and functional prototypes were developed to test both form and functionality. The project ended with a very well-functioning prototype which proved its effectiveness.
Idea & Concept
Current frustrations and bottlenecks were used as a starting point for ideation. After narrowing down ideas, together with the client, a final direction was chosen.
Technology Selection
Different measuring techniques were explored, and the promising ones were subjected to a series of tests to evaluate performance under different circumstances.
Building & Testing
During the project, multiple prototypes were made. Each prototype was tested with potential end users and the obtained insights were implemented in the next iteration.
As a starting point, common frustrations and bottlenecks during DIY-ing were mapped. This was done by conducting interviews with both (inexperienced) DIY-ers, professionals and employees of construction markets, the latter because they have a good overview of the average skills and bottlenecks of the DIY-ers.
The list of frustrations included among others “Not being able to cut in a straight line”, “Screw bits shooting off and damaging screw heads” and “Drilling too deep (and damaging something) or not deep enough”.
Ideation on these problems was done and led to a series of concept designs. In collaboration with SKIL it was chosen to solve the problem of not knowing the current drilling depth, and therefore often drilling not deep enough or too deep.

After selecting the concept that would be developed further, SKIL expressed the desire to start a new product line consisting of ‘smart’ (digital) power tools that would help the inexperienced DIY-ers in their projects. This lead to a revised design brief, saying:
“Design a power tool that can provide the current drilling depth to the user with help of a digital sensor”
Idea & Concept
Current frustrations and bottlenecks were used as a starting point for ideation. After narrowing down ideas, together with the client, a final direction was chosen.
Technology Selection
Different measuring techniques were explored, and the promising ones were subjected to a series of tests to evaluate performance under different circumstances.
Building & Testing
During the project, multiple prototypes were made. Each prototype was tested with potential end users and the obtained insights were implemented in the next iteration.
To calculate the drilling depth, various measuring techniques were considered including optical sensors, acoustical sensors, inertial sensors and capacitive sensors.
A selection was made based on sensor accuracy, range, cost, size and energy consumption. This led to only two remaining measuring techniques: infra-red triangulation and laser Time of Flight for which different sensors were bought.
These sensors were subjected to several experiments, evaluating performance while being subjected to:
- Surfaces of different colors
- Surfaces with different surface finishes (roughness)
- Dust-particles caused by drilling
- Different ambient lighting conditions

Eventually, an Infra Red-sensor using triangulation measuring was selected to be used in the project, showing consistent results under different types of surfaces and environmental conditions.
In triangulation measurement, a short Infra Red pulse is being sent, and this pulse will reflect from the surface and will be collected again by the Infra Red-sensor. The angle at which this reflected pulse arrives says something about the distance between the sensor and the wall.

Idea & Concept
Current frustrations and bottlenecks were used as a starting point for ideation. After narrowing down ideas, together with the client, a final direction was chosen.
Technology Selection
Different measuring techniques were explored, and the promising ones were subjected to a series of tests to evaluate performance under different circumstances.
Building & Testing
During the project, multiple prototypes were made. Each prototype was tested with potential end users and the obtained insights were implemented in the next iteration.
To validate the feasibility of the concept, a rapid prototype was made with the help of a breadboard and some jumper cables. After some quick tests, it became clear that this concept showed enough potential to be developed further.
In the next phase, several concepts were developed, addressing the question of to what extent the tool or the user should be in control. Is the tool supposed to only inform the user about the current drilling depth? However, is the average DIY-er not skilled enough to process this information adequately? Or should the device have a bit more control and warn the user once the desired depth has been reached, or simply control the drill and stop when the desired depth has been reached?
All concepts were tested with inexperienced DIY-ers, and it was concluded that it would be best to let the drill handle the drilling depth, so the user has to solely focus on drilling a straight hole at the right place.
Next to usability, the software of the prototype was also further developed and tuned until the prototype reached a 1 mm accuracy.
For the final prototype, aesthetics and function were combined into one prototype. The electronics assembly was embedded in a 3D printed housing. With this prototype, both from and usability could be evaluated.
The functional prototype includes a potentiometer acting as the speed trigger, the Infra Red-sensor, a microcontroller to calculate the difference between the desired and the actual depth, an LED-bar to show progress to the user and a brushless DC motor to let the drill bit rotate.

03. The Result
More than just a tool
About 10 weeks after the first introduction to the project, it was time to present the final result. For this project, SKIL was very satisfied with the outcome and decided to buy the Intellectual Property of this idea.
?? View the 3D model from all angles by dragging the model below






SKIL Drill Assist
Finding the right drilling depth for your dowels to fit in perfectly can be a frustrating and time consuming task. Either the hole is not deep enough and needs redrilling, or you already went too far. SKIL’s new cordless drill with smart drill-assist can overcome this problem.
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Date
July 3, 2020
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Skills
Electronics, 3D-printing, Prototyping
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Client
SKIL
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Project Type:
Individual Project
