Prototypes

Cold End

To give RAPTER the capability of printing two types of materials, a support material and a print material, the cold end of the printer head must have a switching mechanism to independently pull the two materials to the hot end. This mechanism uses the applied torques the gears can put on the system. Depending on the direction of the input gear the system will shift left or right.The stepper motor is placed in the middle of the four idler gears. The idler gears are placed above the input gear strategically so the gears are not complelty meshed. A demostration of the prototype working is in the video below.

The Hot End is comprised of a milled aluminum nozzle and drilled aluminum heating block. The image to the left is a sample Hot End to experimemtally prove whether or not filament can be extruded using a 12V source with a maximum power output of 25W. Once confirmed 12V could be used to extrude filament, the amount of time needed to bring the Hot End to operating temperature was tested.

Development circuit demonstrating stepper motor drive capability and RS-232 communications with the host PC. A Python script was running on the PC allowing the user to specify a target location for the motors, causing the steppers to go to that location.

Test fixture for the stepper motors. Was used to perform torque analysis on the motors and to demonstrate the drive capabilities of the embedded software.

Test aparatus for linear encoder feedback. Complete testing of the accuracy of the linear encoder has not yet been completed.