me  

How to Build Almost Anything

MAS 863 @ MIT

Press Fit Design via use of Router, Plasma Cutter, or Vinyl Cutter.

 
 
   
 

PROJECTS!

1. CAD design

2. Press Fit

3. Circuits

4. Programming Cables

5. MicroControl.

6. The Future.

         
(Vinyl Cutter)
 
(Router, FabLab)
 
(Router, ArchLab)
   
(Plasma Cutter)
(Material, Plywood)
(Material, Cardboard! )
     
(Small PressFit, Shell Model)
(Medium PressFit, Cool Shape)
(Large PressFit, Fuel Cell Shell)
   
 

The story in text:

The purpose of this lab is to make multi-dimensional creations from two-dimensional objects. Primary material choices included plywood, cardboard, or acrylic. Primary excluded materials include shiny metal and PVC in all of its forms as it off gases toxic. In my case, I am interested in vehicles, or more broadly design to solve global problems and vehicles are a tangible mess of an engineering problem. Over the summer, I lead a project to design and build a fuel cell car with the aim of seeing hydrogen introduced as a safe, biologically derived option for emission free transportation. The car is made of aluminum and the goal was to have 90% recyclability on the first version, so the shell needed to either be a thermoform, polypropylene material or a placeholder shell, specifically a wood skeleton as one might see in an old airplane that allows one to loft a material over the form to achieve the aerodynamic performance of a shell. Given that the body has yet to arrive, I set out to make a shell for the car.

Making the Shell Shape:

1. The most difficult aspect of this assignment proved to be laying out the cross sections, and before that making a shell shape that actually fit the car's chassis. This took many days in fact, involving a steep learning curve required to take a form to its solid phase, subtractive modeling, and then using introduced planes to remove geometries in 2D. Here are some examples, including some of the cross sections:

 
         
Cross Sections in SolidWorks Drawing

2. With cross sections in place, I moved on to cutting them out. This meant saving the files as .DXF and .DWG as I did not remember which worked where, and then trying to learn to use the plasma cutter, but even before that the router! I chose the router because I wanted large sections of material that were thick, and the plasma cutter is too small to manage such a task. With this in mind, I aimed for the Router in the Architecture Lab. I learned quickly that while a simple machine, it has its quirks and needs careful consideration.

The Router:

The router is happiest with .IGS files. It has a vaccum table and pneumatic systems that require another vacuum to operate. It runs following a procedure that is as follows:

First, I met with monitor1@mit.edu (Jeff Anderson) and he provided a set of tutorials on the machine, during which I learned that the running process begins with a flip of the large red switch on the grey control box under the table. Once on, the machine must be asked to pick up the appropriate tool, a step that comes once the file is brought from its CAD origins through EZCam, and on to the

 

 

 
         

 

Cam.py was written

Cam.py after file import.
Cam.py just before clicking send.
 

3. Before sending your file, you must prep the machine. First, pick up the copper plated sheet, and apply double sided tape to half of the back. Place the corner of the plate at 2,2