The electronics board chosen for this project is the Ramp 1.4. This board is a known as a shield. Shields are electronic boards that fit directly on top of the arduino with pins that fit into the ports of the arduino. This board houses the majority of the electronics of this project such as the capacitors, transistors, thermistors, motor drivers, as well as extra pins used for prototyping new designs.
There are two different kinds of motors we considered for this project, stepper motors and servos. Servos have a higher torque at high speeds and are accurate, however they are more expensive than steppers, an encoder is required to be accurate, and they are difficult to service. Stepper motors have high torque at low speeds, but lose torque at high speeds. Stepper motors are sold by the number of steps they have. The more steps the better accuracy they have. They also have the ability to be micro stepped which uses software to stop multiple times within a step. This can be difficult to do but can increase the accuracy of the motor. Due to the price of stepper motors, their accuracy, and their ability to be serviced more easily.
The firmware being considered for this project is called Marlin. It has many features some of which include temperature safety features, high speed and high cornering speeds, supports LCD display, and is compatible with use of a SD card. This firmware will have to be altered somewhat in order to meet all of the group’s needs.
The extruder for a 3D printer is a heated nozzle that directs where the plastic is placed. Plastic filament is pushed through the heated nozzle using a stepper motor. The extruder is moved around the heating bed using two more stepper motors.
The skeleton of the printer will consist of the x, y, and z moving axis. It also houses the extruder and the stepper motors. The skeleton supports the device and keeps it from shifting so that the object being created comes out well.