Process Post

Grace MacPherson and 2 OthersIndia Hyde
Elias Hyde
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Despite drawing being very important in children’s development and very important to many adults, many do not have the ability to draw due to a lack of fine motor control and other issues. The solution to this problem is a simple device that allows a pencil to be controlled with large, imprecise movements. A Myo can be used to control a drawing device with simple and easy movements.

DrawingBot makes drawing easy for people who lack the simple skills needed to draw by helping people create art without actually having to hold or precisely control the pencil. The final iteration of the project uses servo motors to move a pencil connected to the servos through multiple joints. The servos are controlled by a Myo. The drawing device was originally controlled by a timing belt and then a gear and rack until we reached our final idea which we prototyped many times. Though mostly complete, the servos movements must be corrected as well as the control system for the device.

Our first iteration was a simple x and y axis drawing machine composed of tape and cardboard. The horizontal bar was moved vertically by a motor and a belt made out of tape. The pencil was moved horizontally by a motor and belt. The belts were attached to both the horizontal and vertical bar. After building this prototype, we saw that this idea used too many motors and was unstable. We decided we should continue on the idea but make critical changes to make in more stable.

Our second iteration was similar to the first but we redesigned how the motors would be mounted on the device. Instead of hanging on the outside, the motors were mounted inside of the horizontal and vertical bar. This proved more stable but the belt still had flaws when moving and holding the pencil. Along with this, the wires connecting the motors to the Arduino still had no place to stay and would have to be on the outside of the device. We also had yet to make a stable pencil holder.

Our third iteration changed a lot from our first two. This iteration had two servos controlling an arm between them. This iteration took up less space and therefore it was significantly easier to see the drawing. This iteration also eliminated the problem of syncing up the motors. We also could easily hide the wires within a box on which the arm was mounted on. This iteration had some problems that needed to be fixed in the next iteration for example it did not have a pencil holder and the arm was bent upwards.

Our final iteration was similar to our third. We still used an arm between two servos, but we added spacers so the arm was not bent and the iteration had a 3D printed pencil holder. These changes made the arm more stable and move more smoothly. We also made the box the arm was mounted on bigger so the user could draw with the full capacity of the arm.