Lab 4: Prototyping, Manufacturing, and Digital Fabrication
The goal of this 2 weeks lab is to make a "finished interface" from scratch using digital fabrication such as laser cutting. While the final submission is due on Feb. 15, 2018, a milestone (see details below) should be submitted on Feb. 8, 2018.
The first portion of the lab walks you through the steps for making the "Pushy Pushy" controller below. While you will not actually make it, you'll use it starter "template" to make your personalized controller.
Making a Box
Laser cutting is a fast, precise, and efficient way to turn a 2D drawing into a physical element. While various types of materials can be laser cut, we'll use acrylic for this lab as it is cheap and easy to work with.
If Inkscape is not already installed on your system, download it and install it.
Open the SVG file generated during the previous step in Inkscape.
Laser cutters can be used to cut or engrave (raster) specific kind of materials. Not all materials can be used with laser cutting. Therefore, you should always make sure that the materials you use are compatible with laser cutting. For example, acrylic and polycarbonate are plastics that look and feel exactly the same but while acrylic is safe to cut, polycarbonate will release toxic gas when hit by the laser beam.
The CCRMA garage is home of an Epilog Helix laser cutter. Any line whose thickness is exactly 0.001" in an SVG file will be cut. Everything else (e.g., thicker lines, infill, etc.) will be rastered.
Edit the box drawing generated in the previous step so that it sorts of look like this:
The computer of the CCRMA laser cutter is using illustrator to export jobs to the cutter. Since stroke dimensions tend to be slightly changed when going from Inkscape to Illustrator, we decided to highlight in red the parts of the drawing that should be rastered instead of cut.
As the picture presented at the beginning of this lab shows it, our design is made to install an FSR on the top plate of the box. The red circle marks the position of the sensor and the thin rectangle on its left is a hole to bring the tail of the FSR inside the box. The rectangle added on one of the sides of the box is here to give access to the USB port of the Teensy placed inside the box.
The final goal of this lab is to create a custom musical controller based on the generic box generated with http://www.makercase.com/.
Milestone 1 (Due on Feb. 8, 2018)
Think about the sensor(s) you would like to use to make your controller.
Draw a few sketches of potential "box-based controllers."
Spend some time thinking about the type of affordances you'd like them to offer. Think about the types of sounds you want them to control, in other words, think about your instrument as a whole: it should be "mutualized"!
Pick one of your potential design up, choose its dimensions, generate the corresponding box/enclosure 2D drawing using http://www.makercase.com/ and customize it.
Measure precisely (i.e., using calipers) the sensors you're going to use to perfectly integrate them to the enclosure. For example, if you use a rotary potentiometer, measure its diameter to cut the corresponding hole in the box. Always leave some extra room when you do this. For example, if the diameter of the axis of the rotary potentiometer is 6mm, you'll probably want to cut a 7mm hole.
Feel free to change/adapt the shape of the box to your needs.
Add any elements you'd like to raster on the box to the 2D drawing. Be creative and see how this might help integrate sensors to the controller. For example, if you're using a knob, you could raster a scale around it, etc. Make sure that all the elements you'd like to raster are highlighted in red!
If your design becomes really complex, you might want to check if it works by exporting it to OpenSCAD using this tool. This step is completely optional of course.
Double check all your measurements to be sure that everything will fit.
Send a zip file to by Feb. 8, 2018 containing the following elements:
a picture of the sketch of your musical controller (don't spend too much time on this, it should just give the idea of what you're going to do),
a text file containing a short description of your project,
The laser cutter is located in the back of the CCRMA garage, come find us there when your ready to cut!
Save the SVG file of your box on a USB dongle and bring it when you go to the laser cutter room.
Make sure you wrote down the dimensions of your box in case some adjustments are needed.
On the laser cutter computer, open your modified box model (SVG) in Illustrator.
Select all the elements of the file (ctrl + a) and move them to the top left corner of the workspace. For that, you can click on "Transform" and choose 0.05in both for the X and the Y position of the selection.
Select all the parts that you want to cut and make sure that their stroke weight is 0.001".
Select all the parts that you want to raster and make sure their stroke weight is 0.01".
At this point, things should look like this:
The laser cutter works like a printer so click on print or press "ctrl + p".
In the window that pops up, select "setup" and the following window should open:
Make sure the various parameters are the same as in the picture, in particular:
Auto Focus: Yes
Job Type: Combined
Piece Size: should match the size of the piece of acrylic you're about to cut
Raster Speed: 100%
Raster Power: 50%
Vector Speed: 10%
Vector Power: 100%
Vector Frequency: 5000Hz (the last five parameters are optimal of 1/8" acrylic sheets would be different for other materials)
Click on "OK" and then on "Done" in the Illustrator print configuration window.
Click on print again (or "ctrl + p"), this is necessary because the size of the "sheet" needs to be adjusted in function of the material size configured in the previous step.
Now make sure that you're drawing is centered on the top left corner of the sheet as follows:
Now, make sure that the cutter, the compressor, and the exhaust are on and you can start cutting! REMEMBER: AS STINKY AS IT MIGHT GET, YOU MUST ALWAYS BE PRESENT IN THE LASER CUTTER ROOM WHILE A JOB IS IN PROGRESS!
Once your model is cut, assemble it using the provided screws and bolt as shown on the picture at the beginning of this lab.
Wire things up and start controlling your ChucK synth!
Assignment (Due on Feb. 15, 2018)
Make a video of yourself playing your instrument and post it on YouTube.
Send the link of this video along with the source code of your instrument to by Feb. 8, 2018.