2.75 | Fall 2001 | Graduate

Precision Machine Design


The following are projects for teams to complete this semester. Each project will have a project leader responsible for keeping the project on-track. The project leader is in general someone who would want to continue the project as a thesis or other intense personal or professional interest. In general, any of these projects could generate fundamental great journal articles, patents, or maybe even companies.

Some of the possible projects already have significant background work accomplished. Some are mere sketches that need full scale development. ALL must be developed in accordance with weekly milestones. Budgets are essentially nonexistent for machining, so students will have to be ingenious about design and manufacturing and / or competent in the shop. Your grade is based on showing weekly progress.

Some of the projects are feasibility studies (design build, and test experiments) for what could become major new research initiatives. Some already have team leaders, who are the grad students’ whose theses may evolve from the project. Some of the projects will have team coaches (people with whom teams will meet every week) who are researchers at MIT who need machines designed as test apparatus. These are indicated in the project descriptions.

Component Strain Assembly

Thermal strain can be a troublesome source of micron level errors in precision manufacturing. So…. why not achieve micron level manufacturing using controlled thermal or load induced strains? Consider a meso-scale pump or a rheometer that require:

  • non-contact assemblies of shafts and bores with micron level gaps
  • 0.1 micron shaft-bore concentricity

One can use the inherent mechanical compliance or could induce thermal strain of the shaft and/or bore to conform to each other and initially align the centerlines of the shaft and bore. After the components are rigidly fixed to some other component, the thermal or mechanical load can be removed, permitting a gap to open between the shaft and bore.

The goal of this project is to design a method for manufacturing of precision concentric geometry that maintains a micron level gap between the concentric components. The group will design and build an alignment mechanism for either a meso-scale pump or a rheometer.

PCV Valve Tester

Hundreds of tons of carbon get pumped into the atmosphere every year because positive ventilation crankcase valves vent more than the should for fear of freezing shut. New small clearance designs could reduce oil consumption by 75% or more. A test platform is needed to evaluate these new designs.

The goal of this project is to design, build, and test a PCV valve tester to evaluate flow and resistance of the valve to freezing.


Fluid response to shear behavior is measured in a rheometer that consists mainly of a shaft placed coaxial within a bore. The gap between the shaft and the bore is flooded with the fluid of interest, the shaft is turned at desired speed, and the torque required to turn the shaft is measured.

The behavior of fluids at high shear rates (i.e. as experienced in ink jet cartridges) is not well quantified and difficult to test. To mimic shear rates of interest, the radial gap between the rheometer shaft and bore must be on the order of 10 microns. This is ~ 1/12th the thickness of a piece of paper!

The goal of this project is to design a precision location and error motion compensation mechanism/flexure to maintain alignment of the shaft and bore axes within 0.5 micron. This alignment must be maintained as the structure of the machine and environment is exposed to 10°F changes. A means of particle generation/management is also required.

Parallel Robots and Spherical Joints

Parallel robots, such as the ABB FlexPicker, offer benefits in the areas of high speed, high stiffness and improved accuracy. Improvement of the performance of such robots involves an in-depth analysis of all aspects of the robot system, such as control strategies, mechanical design and mathematical modeling. The key question is: how accurate can we make an industrial robot?

Preliminary analysis has revealed the three degree of freedom (3DOF) joints, used to connect the parallel arms between the actuator elements and the tool platform, as a potential source of improvement. Check out the Spherical Joint Design and Test page for more details.

The goal of this project is to design and build a new 3DOF joint and test platform. A parallel robot may also be constructed to evaluate the performance of multiple joints in a realistic robot structure.


Flexures are great bearings that can also be used to create transmissions. This project is concerned with developing flexures to support and guide motion and that are part of a transmission to actuate the motion.

The goal of this project is to develop Flexadjusters for use by the instructor and his optical research team.


Fleas can jump far higher than elephants in proportion to their body size, so why are we making so many small parts on such large machines? Companies like Citizen Watch have for years pioneered small precision machines for making small parts, but are their designs the best?

The instructor has been thinking about the design of a machine that would use the latest in ballscrewspline technology with new modular air bearing bushings to create a small precise multi axis machine tool.

The goal of this project is to design, build, and test a single axis of this concept. THK and NewWay have already agreed to donate the parts.


Robots in hospitals and cleanrooms suffer from the fact that they get in the way of humans. If they are mounted on the ceiling, monorail style, they are very expensive. However, if robots were to take advantage of simpler designs and gravity (its free!) large cost reductions could be realized. Magnabots use magnetic wheels to hold themselves to an iron roadway on the ceiling.

The goal of this project is to design, build, install, and demonstrate a radio controlled MagnaBot material transport system in CIMIT’s operating room of the future in University Park.

Catheter Robots

Catheters are commonly used to image inside the body, and their tips are directed by applying tension to an internal cable, or torsion to the entire catheter. Can several be bundled to form a robotic hand for laperospcopic surgery? What new tools and procedures would result if this concept proves viable?

The goal of this project is to evaluate existing catheters and develop methods for increasing their force and stiffness capabilities at the tip. In addition, look at surgeon’s functions, tools, and techniques, and how could then benefit/change with the availability of a catheterbot?

Flextester II

In 2000, a group of students in course 2.75 developed the “Flextester”, a first prototype that was capable of measuring the force-displacement curve of MEMS devices, featuring a resolution of 1mN for the force, and 100 nm for the displacement. This prototype was designed for proof of concept and it has limitations in terms of adjustability, level of automation, user friendliness…

The goal of this project is to design a new and much more elegant version of the instrument (“F-2) with enhanced capabilities, for example it is desired to be able to measure not only in the wafer plane, but also out of plane, which requires a additional metrology axes. A vision system and a better wafer chuck should be added as well. The project is a straightforward one with a well defined set of functional requirements. There is a lot to learn about precision machine design, flexures, and precision calibration procedures.

Low-Cost, High-Repeatability Kinematic Couplings

Kinematic Couplings are commonly used throughout industry to create interfaces with extremely high repeatability. Two new coupling types, the Kinematic Wavy Spring Washer and the Groove/Cylinder coupling, have been conceptualized by the instructor and his graduate students, but not rigorously investigated. In addition, the effects of coatings, such as Titanitum Nitride, on kinematic coupling surfaces will also be studied.

The goal of this project is to develop design methodology for low-cost precision interfaces using these concepts, then build and repeatability-test prototypes of each concept. These prototypes would be compared to a standard canoe ball-groove configuration in a test setup built by the group. This project is straightforward and would provide experience on kinematic couplings and high-precision (e.g. capacitance probe) measurement systems.

Bike Shifter: Are you an avid biker? Can’t wait to hit the trails after work? Then this project might be for you!

Current shifter mechanisms for both mountain and road bikes change the gear by shifting the the chain between 3 chain rings in the front, and 5 to 8 sprockets in the rear, resulting in anywhere from 10 to 27 gears. In practice, however, many of the resulting gear ratios overlap. In addition, some of the gear combinations may not be usable because the chain would experience too much shear stress due to angular misalignment.

To solve this, a new type of shifter mechanism is proposed that would synchronize the shifting of the front and rear derailleur, resulting in a range of gears with continuously increasing gear ratios. The new mechanism would eliminate the need for having two separate shifter mechanisms at the handle bar through the new shifter that can be mounted either to the right handle bar (for right handers) or left handle bar (for left handers).

The goal of this project is to design, build and patent a product that would hit a niche in a very competitive, yet lucrative market: sports equipment.

NanoComposite Materials Testing Equipment

As part of a DURINT research project sponsored by the US Air Force, samples of a new type of composite need to be tested using an Atomic Force Microscope (AFM). For this purpose, a device that stretches material samples (20 mm long, 5-8 mm wide, 0.5 - 2 mm thick) while monitoring the applied force (up to 12 kN) and strains (up to 600%). The device needs to be compatible with the existing AFM, a Dimension 3100 made by Digital Instruments.

The goal of this project is to supply researchers in the Mechanical and Materials Departments of MIT with a versatile, accurate, yet easy to use materials testing device for a novel type of composite called NanoComposites. Designing and building this device will require good knowledge of power transmission systems, bearings, grippers, force and displacement sensors, and controls.

X-Ray Telescope Optics Modules

X-ray telescopes focus X-rays by grazing incidence optics. However to obtain a reasonable cross section, many many parallel curved plates must be assembled. An early attempt to use a diamond machined reference flat to align the edges of the curved plates demnstrated feasability, but structural deformations from bolts etc. reduced accuracy. This project will create the “final” production-ready system to create the assemblies to be used in the next generation space telescope.

Low Cost Eyeglasses

Over one billion people need glasses but do not own them. People who have correctable vision problems are often handicapped as a result as the lack of correction. Without glasses, simple tasks become more difficult or impossible, productivity slows, and accidents occur more frequently. Based purely on the lack of productivity and enjoyment, the lack of eyeglasses is one of the largest solvable problems in the developing world. In fact, it is significantly more common than often cited problems such as cataracts or glaucoma. Glasses could correct the majority of vision problems encountered in the developing world, reducing the impact of presbyopia, myopia, hyperopia, and astigmatism.

Project 1. Refractometer

The goal of this project is to provide a lowest cost refractometer that will measure refractive errors in the eye including astigmatism.

Project 2: Low cost edger

The goal of this project is to design a milling center that will accurately allign the optical and astigmatic axis of a lens and appropriately cut the edge and bevel to the shape of any arbitrary frame. This project could also fit under the low cost fabricator / machining center project.

Special Topics

Course Info

As Taught In
Fall 2001
Learning Resource Types
Lecture Notes
Design Assignments
Presentation Assignments