Professional architect and designing hobbyist Ekaggrat Singh Kalsi has just shared his very cool Doodle Clock that continuously writes the correct time on a magnetic board (and erases it again).
Ekaggrat is a project architect in Ahmedabad in India, but by night he is an avid 3D printer who loves to tackle unusual projects. And that is certainly a word you could use to describe some of his work.
His latest project is equally impressive, but a bit more tangible. While some other clock projects that rite down the time sometimes circulate the web, few are as impressive as the Doodle Clock. Built as a second generation of a previous project by Ekaggrat, this new version tackles the problem faced by most writing clocks. Typically, they all write down the time on paper or a whiteboard, but in all cases the pen or marker dries up, while the surface eventually also gets ruined.
The same happened with the first iteration of the Doodle Clock. ‘The biggest problem with the first clock was the drying up of the markers after just 30 minutes of working,’ he says on his website. Originally built as a bit of a fun project, the concept fascinated Ekaggrat, so he was very happy to find a solution to this common problem: Magnetic writing boards, often seen in toys. While even whiteboards or glass sheets will eventually get ruined by ink, this magnetic solution can go on writing the time perpetually. Two 2 mm cylindrical magnets inside a solenoid are key. One magnet passes over the board to draw lines, but when the other is passed over the other side, the lines are wiped out – perfect for a clock that news to change the result every single minute of the day.
The build itself is also farily straightforward. All parts are 3D printed, except for the small geared stepper motors that power the arms and the board itself. ‘The clock uses two 1:100 geared 15mm stepper motors to move the arms configured in a scara fashion. The motors are located at the base to keep the weight very low on the arms. The tip of the arms contains two solenoids with cylindrical magnets inside them,’ Ekaggrat explains. ‘I initially tried electromagnets but to get the text to be as dark as what is written by the magnet which comes along with the board needed a lot of power.’ The only problem is that the board eventually gets a bit scratched by the magnets, but the designer is looking to cover it with a very thin scratch resistant film to deal with this issue.