From Fab @ Home

Summary

A Model 2 in the Cornell Computational Synthesis Lab, the home of the project.

The Model 2.0 is the latest printer in the Fab@Home family. The design has been simplified to reduce cost, build time, and required skill level. It is easy and affordable to build and modify due to use of a pre-built motor control system, and numerous refinements and improvements in the design of the chassis itself in order to reduce complexity.

The Model 2 introduces:

• Closed loop postioning systems
• plug and play electronics
• multiple interchangeable tool heads.

Model 2 Beta was released in August of 2009 and information related to it can be at Fab@Home:Model2Beta.

Mechanics

The Model 2 is a standard gantry system in the same vein as Model 1. The build table moves along the z-axis, and the tool moves in the x and y directions. The drive-train has been changed to a belt drive which reduces the cost and complexity of the machine. All of the parts, aside from the screws, nuts and inserts used to secure the chassis, have been switched to the metric system to enable the creation of units outside of the United States with greater ease.

Electronics

The system is now entirely wired via cat5 cabling thanks to the snap motors and control system from JrKerr. See: Fab@Home:Cables and Fab@Home:Electronics.

Software

The Model 2 currently uses different control software than the Model 1. The Model 2 Software page gives more detailed documentation. There are two parts to the control software.

• FabStudio imports STLs and tool files and outputs a series of layers and paths in the form of a fab file.
• The FabInterpreter controls the printer and converts fab files into motion.

Both of these programs are part of a redesign of the software and hardware interactions.

For more information on how to the code works and what is planned for the software, please see the Fab@Home Lauchpad project site.

You can download the software from the main site

Building a Model 2

To build and use a standard Model 2, you will need to do the following:

1. Buy tools required for assembly
2. Choose your style options
3. Buy or make the parts for the Model 2
4. Build the cables and sub-assemblies
   1. Bridge and Tool Carriage Assembly
   2. Z-Carriage Assembly
   3. Chassis Assembly
   4. Dual Syringe Tool
   5. Cables
5. Assemble the sub-assemblies into the complete Model 2 System. NOTE: Detailed assembly instructions are currently in development. Please refer to the complete text only instructions here for places where diagrams/photographs are unavailable:
   1. Final Assembly
6. Install the Fab@Home Model 2 Application
7. Commission the Model 2
8. Use the Model 2
9. Package the Model 2 for Shipping

Tools

1. Plastic Tool System
   1. Plastic Tool
   2. Heated Build Base
   3. Temperature Controller
   4. Fume Extractor
   5. Use the Plastic Tool System
2. Syringe Based Tool Systems
   1. Single syringe displacement tool
   2. Dual syringe displacement tool
   3. Dual syringe Valve tool
3. Milling tools
   1. Dremel Mount tool

Looking forward

Since updating and distributing hardware is capital intensive, it will be done on a semi regular basis. Major release will occur on the scale of years, and minor releases will occur on the scale of months. For a list of goals and proposed solutions see our Blueprint