Pipetter Makerbot

3D-printer modified for chemical deposition of controlled volumes at user-determined locations using a repeater pipette. Project was featured on CBS Science Blog smartplanet.com  and MakerBot Explorer

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This work was done with the Innovations in International Health Lab at MIT under the supervision of Jose Gomez-Marquez. Below is the pipetter in action.

 

In this post, we’ll discuss the capabilities of the machine and an overview of the mechanisms involved.

A MakerBot 3D printer has: 3 stepper motors (X, Y, Z axis) 3 end stop sensors (X, Y, Z axis) 1 power supply 1 printing platform with movable top 1 extruder mechanism with motor for extrusion

mb-eSource: MakerBot Industries

3D Printer in Extrusion Mode

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3D Printer as a Pen Plotter

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We implemented three systems: a liquid deposition system, pen plotter and 3D printer.

The cost was under $1300. This is a fraction of the cost of industrial-grade machines that although faster, are also out of reach for small scale laboratory applications.

Further Hardware Development 

Implement other z-platform devices with pulse width modulated (PWM) input signal. They can be controlled using the same Gcode commands than the repeater pipette.
Experiment with DC voltage devices at extruder motor board input.

Further Software Development 

Implement custom Gcodes for branching and conditionals. This will increase the capabilities of the Makerbot
Implement additional Gcodes: to disengage servo motors, or read voltages at relevant board pins.

Skills Applied in this Project

– Gcode
– CNC
– CAD
– Inkskape
– Java
– Python
– C++
– ReplicatorG
– Customized windows drivers. Path, system and environmental variables
– Compiling windows firmware with AVR-GCC, averdude, scons
– Compiling linux firmware with gcc-avr avr-libc avrdude scons git-core
– Servos
– DC motors
– Temperature sensors
– Endstop switches
– High-temperature extrusion systems
– Design of analog sensors
– Electronics assembly/soldering and testing