15-394 Intermediate Rapid Prototyping

Monday / Wednesday 2:20 ‐ 3:40, Hunt Library 106B or virtual in Zoom

Spring 2021

Units: 5.0, Section: A4


Professor: Dave Touretzky, dst@cs.cmu.edu TA: Daniela Castleberg, dcastleb@andrew.cmu.edu
Office hours: Wednesdays 11:15 AM to 12:15 PM (on Zoom)
TA: Lee Poirier, lpoirier@andrew.cmu.edu
Office hours: Fridays 9:00 AM to 10:00 AM (on Zoom)
TA: Anushka Saxena, anushka2@andrew.cmu.edu
Office hours: Thursdays 5:00 PM to 6:00 PM (on Zoom) and Saturdays 1:00 PM to 2:00 PM

Course Description

This course introduces students to more advanced techniques in rapid prototyping, building upon skills learned in the introductory course 15-294 (Rapid Prototyping Technologies). It covers three main topics:
  1. Mechanism design and physics-based simulation in SolidWorks.

  2. Parametric design and computational geometry using Grasshopper.

  3. 3D scanning, mesh manipulation, and 3D printing.

After completing the course you will have access to the IDeATe laser cutting and 3D printing facilities for the rest of your time here at CMU. You are welcome to use these facilities for future class projects, research, or personal projects.

The only prerequisite for the course is fluency in SolidWorks at a level comparable to what is taught in 15-294. Also, you should know how to use the IDeATe laser cutters, but if you don't, the TA's can teach you.

Learning Objectives

After taking this course, you will be able to:
  1. Recognize and describe mechanisms such as four bar linkages, cams, and gear trains.

  2. Design mechanisms in SolidWorks.

  3. Construct physics-based simulations of the mechanisms you design.

  4. Produce photo-realistic renderings of mechanisms.

  5. Design parameterized 3D structures in Grasshopper.

  6. Export structures from Grasshopper for 3D printing.

  7. Produce 3D scans of small objects.

  8. Manipulate mesh representations of scanned objects.

  9. 3D print complex shapes using dissolvable support material.

Learning Resources

  • There is no textbook for the course.

  • The software required for this course has been installed on the IDeATe laptops which can be checked out from the IDeATe lending booth. The software is also available on machines in the Windows clusters. You also have the option of installing the software on your personal laptop via the Andrew software repository. For Rhino/Grasshopper, which is used in the second half of the course, you can download a free trial copy that is good for 90 days.

  • Cabaret Mechanical Movement, a guide to automaton design.

  • The IDeATe Resources site has information about IDeATe equipment, courses, policies, and more.

  • SolidWorks 2019 Essential Training at Lynda.com may be useful to you; log in here.

  • Grasshopper Essential Training at Lynda.com may also be useful.


There are no exams in this class. The final course grade will be calculated using the following categories:

Assignment #1: Mechanism20 points
Assignment #2: Automaton    20 points
Assignment #3: Parametric surface20 points
Quizzes10 points
Final Project30 points
Total  100 points

  • In Assignment 1 you will select a complex mechanism from a library of choices, impelement that mechanism, and simulate it.

  • In Assignment 2 you will design an automaton using cams and other mechanisms.

  • In Assignment 3 you will modify a Grasshopper program to produce a complex 3D surface.

  • For the final project, which is a substantial fraction of your grade, you will design, fabricate, and document something meaningful to you, drawing on the various techniques you learned in the course. Your project will be displayed in the class gallery.

The following letter grades will be assigned based on calculations coming from the course assessment section.
Grade   Percentage Interval
A 90% - 100%
B 80% - 89%
C 70% - 79%
D 65 - 69%
R (F) below 65%

Grading Policies

  • Late-work policy: Assignments are due at 11:59 pm on the date shown in the class schedule. They can be submitted up to two days late at a cost of 1 point per day. Assignments more than 2 days late will not be accepted.

  • Make-up work policy: Students can make up work if they miss a deadline due to illness (with a doctor's note).

  • Re-grade policy: If you believe your assignment was graded incorrectly, please contact the TA who graded it. We will be happy to take another look.

  • Attendance policy: Attendance is worth 10% of your grade. A sign-in sheet will be circulated at the beginning of each class. You will be allowed 3 unexcused absences without penalty. Additional absences incur a 10 point penalty. Excused absences include illness (with a doctor's note), and participation in certain university-sponsored activities such as a team sporting event. Job interviews and other personal activities do not qualify as excused absences.

Course Policies

  • Academic Integrity and Collaboration: The work you submit in this course must be your own. You are welcome to help or receive help from your fellow students on general matters such as how to fix a SolidWorks error, but you may not share your SolidWorks files with other students, collaborate on writing Python code, or in any other way submit or take credit for work that is not purely your own.

    For final projects, it is common to take inspiration from and build upon the work of others. This is permissible provided that you cite your sources and explain how you went beyond their work to make the project your own.

  • Class Communication: We will use Piazza as our primary means of online communication. Please ask questions via Piazza rather than emailing the instructor or TAs directly, so that your fellow students can benefit from the discussion. Sometimes a classmate may be able to answer your question more quickly than the instructor or TAs.

  • Use of the IDeATe Facility: Please read and become familiar with the IDeATe lending and purchasing policies, which can be accessed at resources.ideate.cmu.edu. Please note that fines may be imposed for late return of equipment.

    The IDeATe facilities are shared student resources and spaces. As such, all members of the IDeATe community are expected to be respectful of the equipment, the spaces, and fellow students and their projects. Always clean up after completing your work, put things back in their correct place, and leave the lab in better condition than you found it.

  • Reporting Problems to IDeATe: if you encounter problems with the laser cutters or 3D printers, please talk to the staff in the IDeATe lending booth, or email help@ideate.cmu.edu. That account is monitored by multiple staff persons and is the quickest way to get help.

  • Purchase of Materials: While we will provide you with some materials, you may need to purchase additional materials to complete class projects. For convenience, some materials are available for purchase at IDeATe Lending (Hunt A29). Additional materials, such as wood, can be purchased at the CMU Art Store in the Cohon University Center. Scrap materials, located in the bins opposite the laser cutters, are free for anyone to use.

  • Accomodations for Students with Disabilities: If you have a disability and have an accommodations letter from the Disability Resources office, I encourage you to discuss your accommodations and needs with me as early in the semester as possible. I will work with you to ensure that accommodations are provided as appropriate. If you suspect that you may have a disability and would benefit from accommodations but are not yet registered with the Office of Disability Resources, I encourage you to contact them at access@andrew.cmu.edu.

  • Statement of Support for Students' Health and Well-Being: Take care of yourself. Do your best to maintain a healthy lifestyle this semester by eating well, exercising, avoiding drugs and alcohol, getting enough sleep, and taking some time to relax. This will help you achieve your goals and cope with stress.

    All of us benefit from support during times of struggle. There are many helpful resources available on campus and an important part of the college experience is learning how to ask for help. Asking for support sooner rather than later is almost always helpful.

    If you or anyone you know experiences any academic stress, difficult life events, or feelings of anxiety or depression, we strongly encourage you to seek support. Counseling and Psychological Services (CaPS) is here to help: call 412-268-2922 and visit their website at http://www.cmu.edu/counseling/. Consider reaching out to a friend, faculty or family member you trust for help getting connected to the support that can help.

Course Schedule

Please see the course schedule page for a list of lectures, assignment issue dates, assignment due dates, and office hours sessions.

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