Capability & Application
Propose at least one capability and one application that you will be responsible for, and describe what they are (and why) on your class site.
Application:
Robot arm
Capability
Grabber
Project Context: Stack & Fasten Machine
How to stack and fasten almost anything
I am interested in making a machine that could stack and fasten almost anything using one repeated elements in a structure. It can be a soda can, bricks, LEDs, cubes or anything that is solid with a consistent form. I could use a pick and place machine or a robotic arm for this application. The hand of the robotic arm or the picker would perform similar tasks. The machine must be able to plan the path to stack one elements at a time in 3D space.
The final goal is to use a sets of ready made objects to construct a structure that might require different strength in different ares in a structure.
For the 1st phase of the project, the machine should be able to pick and place elements in 2D space.
Workflow
- Input element size & fastener type
- Determined speed & feed rate
- Input STL & path planing / Error detection (built size, over hang, support)
- Determined the order of the operation.
Move arm to material supply > Pick > Apply Adhesive > move arm to target > Place
or
Move arm to material supply > Pick > move arm to target > fasten (screw / spin tool head / Press fit) - Repeat
Readings – My Notes
• How to Make Almost Anything: The Digital Fabrication Revolution, Neil Gershenfeld, Foreign Affairs (91), pp. 43-57 (2012)
the ability to turn data into things and things into data.
make what you cannot buy.
Labs like mine are now developing 3-d assemblers (rather than printers) that can build structures in the same way as the ribosome.
♥
Trash is a concept that applies only to materials that don’t contain enough information to be reusable. … It can simply be disassembled and the parts reconstructed into something new.
The Science of Digital Fabrication
“digital processes that can build reliably with unreliable materials by coding their construction from discrete components.”
Precision manufacturing – Dornfield & Lee, 2008, Parts I & II (P1-48)
“random results are the consequence of random procedures.” – Jim Bryan
“By this we mean that machine tool errors obey cause-and-effect relationships, and do not vary randomly for no reason. Further, the causes are not eso- teric and uncontrollable, but can be explained in terms of familiar engineering principles.” – Dr. Robert Donaldson
Critical elements of manufacturing (McKeown)
- To eliminate ‘fitting’ and promote assembly especially in auto- matic assembly (emphasis in the original)
- To improve interchangeability of components
- To improve quality control through higher machine accuracy capabilities and thence reduce scrap, rework, and conventional inspection
- To achieve longer wear/fatigue life of components
- To achieve greater “miniaturization and packing densities”
- To achieve further advances in technology and science.
“reduction of uncertainty”
Necessary in Unit Processes
- source of energy or relative motion
- means to secure the work
- means to secure and orient the tool
- control of the source of energy and means above
VTn =C
V is the cutting speed, T is the tool life, and n and C are em- pirically-obtained constants
“Precision manufacturing ultimately comes down to a process acting on a workpiece.”
Nakazawa design principles
- possessing a perfect kinematic reference,
- possessing a perfect kinematic pair which execute perfect movement with respect to the reference,
- being constructed so as to prevent noise (or disturbances) in operation, and
- being able to detect movement accurately.
The principle of functional independence and states? (Nakazawa)
Mechanical arts: geometry, standards of length, roundness
Social Choice in Machine Design, David Noble 1979
“Technology, then, is not an irreducible first cause; its social effects follow from the social causes that brought it into being: behind the technology that affects’ social relations lie the very same social relations. Little wonder, then. that the technology usually tends to reinforce rather than sub‐ vert those relations.”
N/C was always more than a technology for cutting metals, especially in the eyes of its MIT designers, who knew little about metalcutting: it was-a symbol of the computer age, of mathematical elegance, of power, order, and predictability, of continuous flow, of remote control, of the automatic factory. Record‐ playback. on the other hand, however much it represented a significant advance on manual methods. retained a vestige of traditional human skills; as such. in the eyes of the future (and engineers always confuse the present and the future) it was obsolete.
As the direct result of this unprecedented effort. computer technology was demystified for the union. and the union‐and labor in general‐was demystified for the computer scientists at the Center; the union became more sophisticated about the technology and the technical people became more attuned to the needs and disciplines of trade unionists.
“the union has succeeded in securing for all of the people on the shop floor complete access to the computer-based production and inven‐ tory systems.just asCNC has made automatic machining more accessible to shop‐floor control.” – Yeah!
♥”The social relations of production shape the technology of production as much as the other way around.”
A Parable of Automation – James Fallows 1984 NY Review of Books
“Even for its subsidized users, numerical control could be a source of ceaseless headaches. Programs designed to prevent the operator from “tampering” with taped settings also prevented him from correcting the inevitable bugs and errors. “
” social circumstances have determined the use of technology, rather than the other way around.” – David F. Noble
♥R/P programming was, as one proponent described it, programming by doing…. The program, therefore, was a record not only of the machine (and stylus) motions but also of the machinist’s intelligence, skill, tacit knowledge, and judgment, which were embodied in those motions. Rather than viewing the possibility of human intervention cynically, as merely the chance for “human error,” this approach viewed it positively, as the opportunity for human judgment, skill, and creativity.
Given the emergent obsession with total, automatic control, a system such as this, which relied so heavily upon human skill in the preparation of tapes, was deemed obsolete upon arrival. – GE
the compulsion to automate (and to dominate)…continues apace (and resistance grows). As a result, we see, not the revitalization of the nation’s industrial base but its further erosion;…not the replenishing of irreplaceable human skills but their final disappearance; not the greater wealth of the nation but its steady impoverishment;…not the hopeful hymns of progress but the somber sounds of despair, and disquiet. – Noble
Featured Cover Image: federico díaz geometric death frequency 141