The pulse plotter
Our group project, the pulse plotter, is a machine writing the rhythm’s signal of a beating body. The machine made of a transparent box. It has two mechanism one is the writing pen and the other is the rotating paper loop. The pen mechanism based on Jens design and the paper mechanism took of a printer. Each mechanism work with a stepper motor. Using the pulse sensor, the machine shows only the present moment and doesn’t store data because of the endlessly rotating paper.
The machine consist:
- An analog heartbeat sensor used as input data/analog signal.
- An Arduino Uno board used as microcontroler.
- Two 12V stepermotors used as output to drive the mechanism.
- Two stepermotors controllers used as shields to make 5V powered Arduino control 12V motors.
- An AC/DC converter 220V/12V used as motors power supply.
- A belt and pulley mechanism used to roll the paper.
- A rack and pinion mechanism used for the marker motion.
The first prototype
My part on this group assignment was the fabrication and the assembling of the machine. We made the first prototype out of laser cutted 5mm plywood. The parts we fabricated included the pen mechanism and the machine box. After succeeding working the pen mechanism we fabricated the box. When planning the box we took Into account both of the mechanism. We started assembling the box leaving room for adjusting the paper mechanism motor position.
The final model
We followed the steps of the prototype assembling facing some problems along the way. For the the marker mechanism gear we made several layers for achieving a smoother movement. The rack made from two layers of perspex glued together. We had to adjust the motor rail’s undercarriage. In addition for the first time we assembled the paper loop and its eraser. The project wouldn't carried out without Ilia 3D model designing and Guy breaking the programing matter.
download f3d.FileFuture development opportunities
The pulse plotter project is suitable as an educable activity for a fablab. It include digital fabrication, programing, electronics and 3D designs. Linking all these subjects together with basic biological understanding is a great way of learning!!!
***Although each one of us had his own mission on the group assignment, we worked as a team all along and supported one another***