Final Design

Final Design of Soft-materials Printer

The final design of the soft-materials printer consists of an injection system and a heating system mounted onto a Anet A8 printer without the stock printing head. Additionally, there are voltage regulators and Arduino Uno to control the motor and fan speed and cartridge heater temperature. The injection system is mounted in place of the printing head and the heated fans system is mounted on both sides of the chamber to direct air flow onto the extruded polymer. Dragon Skin part A & B are loaded on the syringe pump(60 ml) before printing and is pumped through the mixing chamber. The well mixed Dragon Skin is then extruded onto the printing platform and cured by the convective heating fans.

            Annotated Injection System                                       Final Mixer

Final Design of Injection System:

The final injection system consists of a 12V DC motor coupled to a mixer that is enclosed inside the mixing chamber. The mixing chamber and mixer are 3D printed from a high resolution(15 microns) 3D printer. Dragon Skin part A & B enters the mixing chamber through flexible tubings attached to the connectors on the side of the chamber. A syringe pump is used to apply pressure to syringes containing Dragon Skin part A & B to ensure they enter the chamber in a 1:1 by volume ratio. The motor is controlled by a voltage regulator and rotates at about 400 rpm to ensure that Dragon Skin part A & B are well mixed when it enters the mixing chamber. The mixed Dragon Skin leaves the chamber through a 0.71 mm disposable tip onto the printing platform. The orange mount is used to mount the injection system onto the 3D printer and to ensure that the motor, shaft, and mixing chamber are aligned.

         Annotated Heating Fan System                    Front View of Heating Fan

Final Design of Convective Heating Fans:

The fans used for the heating fan system are 12V DC fans that are controlled through an Arduino Uno. The fan blows room temperature air through a wooden block, allowing the streamlines to straighten out, and finally through an aluminum block heated to about 100 degrees Celsius. As a result, the air that flows through the extrusions on the aluminum block is about 40 degrees Celsius which is blown over a general area of the 3D printing platform. The wood block on top of the fan is used to reduce convective and radiative heat transfer from the aluminum block to the mixing chamber to ensure that the Dragon Skin does not prematurely cure. The wood connector on the side is used for connecting the heating system to the 3D printer. The set-pin on the side is to ensure that the cartridge heaters make contact with the aluminum block for consistent heat transfer.

Summary of Printer's Performance

The soft-materials printer is capable of printing both 2D(1 layer) and 3D(multiple layers) objects. For 2D printing, the resolution of the print can range from 0.7 mm to 1.0 mm, depending on the syringe pump speed, and is also capable of printing both straight and curved geometries. For 3D printing, the resolution is about 1.0 mm with a layer of about 0.8 mm. The soft-materials printer is capable of printing objects made of more than 40 layers. 

Limitations on Prints

Most 3D objects can be printed with the soft-materials printer as long as there are no bridges.

This printer requires each layer to have a minimum footprint of at least 1250 mm^2 or 45 seconds printing time per layer. The soft-materials printer is unable to print objects with bridges.