Jump to content

RepRap

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by HEL (talk | contribs) at 03:38, 4 May 2010 (→Other materials: Chocolate: proposed by whom??). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

RepRap version 1.0 (Darwin)
RepRap version 2.0 (Mendel)
Video introduction to 'Mendel'

The RepRap project, short for "replicating rapid prototyper", is an initiative to develop a 3D printer that can print most of its own components. All of the designs produced by the project are released under an open-source license. It is self-replication that distinguishes the RepRap Project from the similar open-source Fab@Home project.

To date, the RepRap project has released two 3D printing machines: "Darwin", released in March 2007, and "Mendel", released in October 2009. Developers have named each after famous biologists, as "the point of RepRap is replication and evolution".[1]

Due to the self-replicating ability of the machine, authors envision the possibility to cheaply distribute RepRap units to people and communities, enabling them to create (or download from the internet) complex products without the need for expensive industrial infrastructure. They intend for the RepRap to demonstrate evolution in this process as well as for it to increase in number exponentially.[2][3]


Intentions

The stated goal of the RepRap project is to produce a pure self-replicating device not for its own sake, but rather to put in the hands of individuals anywhere on the planet, for a minimal outlay of capital, a desktop manufacturing system that would enable the individual to manufacture many of the artifacts used in everyday life.

The self-replicating nature of RepRap could also facilitate its viral dissemination and may well facilitate a major paradigm shift in the design and manufacture of consumer products from one of factory production of patented products to one of personal production of un-patented products with open specifications. Opening up product design and manufacturing capabilities to the individual should greatly reduce the cycle time for improvements to products and support a far larger diversity of niche products than the factory production run size can support[4].

From a theoretical viewpoint, the project is attempting to prove the following hypothesis:

Rapid prototyping and direct writing technologies are sufficiently versatile to allow them to be used to make a von Neumann Universal Constructor.[5]

Background

First part ever made by a Reprap to make a Reprap, fabricated by the Zaphod prototype, by Vik Olliver {2006/09/13}

RepRap was founded in 2005 by Dr Adrian Bowyer, a Senior Lecturer in mechanical engineering at the University of Bath in the United Kingdom.[6]

Currently (May 2010), low-end commercial 3D prototypers cost about US$20,000 (from Z Corporation[7]), or Dimension[8]), not including the price of materials and solidifiers, which can cost a further $1500. Prototypes made by these low-end commercial machines cost around US$2 per cubic centimeter to fabricate. The RepRap Project has produced a 3D prototyping machine and free and open source accompanying software that costs about US$400 to build, and which can fabricate objects at a cost of about US$0.02 per cubic centimeter.[citation needed]

RepRap uses a variant of fused deposition modeling technology.

Timeline

All of the plastic parts for the machine on the right were produced by the machine on the left. (Adrian Bowyer (left) and Vik Olliver(right) are members of the RepRap project.)
Version 2 'Mendel' holding recently printed physical object next to the driving PC showing a model of the object on-screen
  • 23 March 2005 - The RepRap blog is started.
  • 13 September 2006 - The RepRap 0.2 prototype successfully printed the first part of itself which was subsequently used to replace an identical part originally created by a commercial 3D printer.
  • 9 February 2008 - RepRap 1.0 "Darwin" had successfully made at least one instance of over half its total rapid-prototyped parts.
  • 14 April 2008 - Possibly the first end-user item is made by a RepRap - a clamp to hold an iPod securely to the dashboard of a Ford Fiesta.
  • 29 May 2008 - Within a few minutes of being assembled, the first completed "child" machine made the first part for a "grandchild" at the University of Bath, UK.
  • As of 23 September 2008, at least 100 copies had been produced in various countries. The exact number of RepRap in circulation at that time is unknown.[9]
  • 30 November 2008, First documented "in the wild" replication occurs. Replication completed by Wade Bortz, the first user outside of the developers team to produce a complete set for another person.[10] Sale is completed in person after meeting over internet.
  • 20 April 2009 - Announcement of first electronic circuit boards produced automatically with a RepRap. Using an automated control system and a swappable head system capable of printing both plastic and conductive solder. Part is later integrated into the RepRap that made it.[11]
  • 2 October 2009 - The second generation design, called "Mendel", prints its first part. The Mendel's shape resembles a triangular prism rather than a cube.
  • 13 October 2009 - RepRap 2.0 "Mendel" is completed[12] and released to the public[13].
  • 27 January 2010 - The Foresight Institute announced the "Kartik M. Gada Humanitarian Innovation Prize" for the design and construction of an improved RepRap. There are two prizes, one of $20,000, and another of $80,000.

Hardware

Any rapid prototyper meant to self-replicate is, by definition, a "RepRap", although to date most have been based on either the Darwin or Mendel design. As an open-source project designed to encourage evolution, many variations exist, and the designer is free to make modifications and substitutions as they see fit. However, RepRap 3D printers generally consist of a thermoplastic extruder mounted on a computer-controlled Cartesian XYZ platform. The platform is built from steel rods and studding connected by printed plastic parts. All three axes are driven by stepper motors, in X and Y via a timing belt and in Z by a leadscrew.

Thermoplastic Extruder

At the heart of the RepRap is the thermoplastic extruder. Early extruders for the RepRap used a geared DC motor driving a screw pressed tightly against plastic filament, forcing it past a heated melting chamber and through a narrow extrusion nozzle. However, due to their large inertia, DC motors cannot quickly start or stop, and are therefore difficult to control with precision. Therefore, more recent extruders use stepper motors (sometimes geared) to drive the filament, pressing the filament between a splined or knurled shaft and a ball bearing.

Darwin

The first publicly-released RepRap, Darwin has an XY gantry mounted above a moving Z-axis print bed. Darwin's Z axis is constrained by a leadscrew at each corner, all linked together by timing belts to turn in unison. Electronics are mounted on the steel supports of its cuboid exterior, and on a second platform at the base. In an effort to minimize the number of non-printed components (or "vitamins"), Darwin uses printed sliding contact bearings on all of its axes.

Mendel

Mendel replaced Darwin's sliding bearings with ball bearings, using an exactly-constrained design that minimizes friction and tolerates misalignment. It also rearranged the axes, so that the bed slides in the horizontal Y direction, while the extruder moves up and down and in the X direction. This makes Mendel less top-heavy and more compact than Darwin, while also removing the overconstraint of Darwin's four Z axis leadscrews.

RepStraps

A 3D printer built to produce RepRaps, but which is not made from printed parts, is often referred to as a "RepStrap" (for "bootstrapped RepRap") by the RepRap community. Some RepStrap designs are similar to Darwin or Mendel, but have been modified to be made from laser cut sheets or milled parts.[14][15] Others, such as the Makerbot, share some design elements in common with the RepRap (especially electronics) but with a completely reconfigured mechanical structure.

Electronics

RepRap's electronics are based on the popular open-source Arduino platform, with additional boards for controlling stepper motors. The current version electronics uses an Arduino-derived Sanguino motherboard, and an additional, customized Arduino board for the extruder controller. This architecture allows expansion to additional extruders, each with their own extruder controller.

Software

RepRap has been conceived as a complete replication system rather than simply a piece of hardware. To this end the system includes computer-aided design (CAD) in the form of a 3D modeling system and computer-aided manufacturing (CAM) software and drivers that convert RepRap users' designs into a set of instructions to the RepRap hardware that turns them into physical objects.

Two different CAM toolchains have been developed for the RepRap. The first, simply titled "RepRap Host", was written in Java by lead RepRap developer Adrian Bowyer. The second, "Skeinforge", was written independently by Enrique Perez. Both are complete systems for translating 3D computer models into G-code, the machine language that commands the printer.

Virtually any CAD or 3D modeling program can be used with the RepRap, as long as it is capable of producing stereolithography files. Content creators make use of any tools they are familiar with, whether they are commercial CAD programs, such as SolidWorks, or open-source 3D modelling programs like Blender.

Materials

RepRap 0.1 building an object

RepRaps print objects from ABS, Polylactic acid, and similar thermopolymers.

Polylactic acid has the engineering advantages of high stiffness, minimal warping, and an attractive translucent colour. It is also biodegradable and plant-derived.

Unlike in most commercial machines, RepRap users are encouraged to experiment with printing new materials and methods, and to publish their results. Methods for printing novel materials (such as ceramics) have been developed this way.[16]

The RepRap project has not yet identified a suitable support material to complement its printing process.

Electroconductive materials

Printing electronics is a major goal of the RepRap project.[citation needed] Several methods have been proposed:

  • Wood's metal or Field's metal — low-melting point metal alloys to incorporate electrical circuits into the part as it is being formed.
  • Silver-filled polymers — are commonly used for repairs to circuit boards and are being contemplated for use for electrically conductive traces.
  • Direct extrusion of solder[17]
  • Conductive wires - can be laid into a part from a spool during the printing process [18]

Other materials

Chocolate has been proposed[citation needed] as a whimsical extruded material. This could allow the manufacture of complex 3D Easter eggs and other such items.

Limitations of self-replication

Although it appears likely that RepRap will be able to autonomously construct much of its mechanical components in the near future using fairly low-level resources, it would still require an external supply of several currently non-replicable components such as sensors, stepper motors or microcontrollers. A certain percentage of such devices will have to be produced independently of the RepRap self-replicating process. The goal is, however, to asymptotically approach a 100% replication over a series of evolutionary generations.

As one example, from the onset of the project the RepRap team has explored a variety of approaches to integrating electrically conductive media into the product. Success on this initiative should open the door to the inclusion of connective wiring, printed circuit boards and possibly even motors in RepRapped products[19]. Variations in the nature of the extruded, electrically conductive media could produce electrical components with different functions than pure conductive traces, not unlike what was done in John Sargrove's sprayed-circuit process of the 1940s (also known as Electronic Circuit Making Equipment or ECME).

Project members

Meccano repstrap of RepRap 0.1 prototype (created by Vik Olliver).
  • Sebastien Bailard, in Ontario.
  • Dr. Adrian Bowyer, Senior Lecturer in the Mechanical Engineering Department University of Bath.[6]
  • Michael S. Hart, creator of Project Gutenberg, in Illinois.
  • Dr. Forrest Higgs, Brosis Innovations, Inc. in California.
  • Rhys Jones, postgraduate in the Mechanical Engineering Department at the University of Bath.
  • James Low, undergraduate in the Mechanical Engineering Department at the University of Bath.
  • Simon McAuliffe, in New Zealand.
  • Vik Olliver, Diamond Age Solutions, Ltd. in New Zealand.[20]
  • Ed Sells, postgraduate in the Mechanical Engineering Department at the University of Bath.
  • Zach Smith, in the United States.
  • Erik de Bruijn, in The Netherlands.[21]

Sponsors

  • Reece Arnott
  • The Bath University Innovative Manufacturing Research Centre[22]
  • The Engineering and Physical Sciences Research Council[23]
  • The Fluorocarbon Co. Ltd.[24]
  • Michael Ingram
  • Lukasz Kaiser
  • The Nuffield Foundation
  • Carl Witty

See also

References

  1. ^ "Future Plans, RepRap Wiki". Retrieved 2010-05-02.
  2. ^ "Philosophy Page, RepRap Wiki". Retrieved 2010-05-02.
  3. ^ "Wealth Without Money, Adrian Bowyer". Retrieved 2010-05-02.
  4. ^ "Introduction to Reprap". ReprapDocs. Retrieved 2007-02-15.
  5. ^ "RepRap". Genesis. Retrieved 2007-02-17.
  6. ^ a b "Adrian Bowyer". University of Bath. Retrieved 2006-06-04.
  7. ^ "ZPrinter 310 Plus". Z Corporation. Retrieved 2010-05-02. USA MSRP - $19,900
  8. ^ "Dimension uPrint Plus". Stratasys. Retrieved 2010-05-02. USA MSRP - $19,900
  9. ^ http://www.seedmagazine.com/news/2008/09/mechanical_generation.php
  10. ^ http://www.reprap.org/bin/view/Main/ItemsMade
  11. ^ "First reprapped circuit". RepRap blog. {{cite web}}: External link in |publisher= (help)
  12. ^ "Mendel Uploaded!". RepRap blog. {{cite web}}: External link in |publisher= (help)
  13. ^ "WebHome". RepRap Home Page. {{cite web}}: External link in |publisher= (help)
  14. ^ "Isaac RepStrap, RepRap Wiki". Retrieved 2010-05-02.
  15. ^ "Lasercut Mendel, RepRap Wiki". Retrieved 2010-05-02.
  16. ^ "First successfully printed ceramic vessel". Unfold Fab. Retrieved 2010-05-02.
  17. ^ "First RepRapped Circuit". Rhys Jones. Retrieved 2010-05-02.
  18. ^ "RepRap SpoolHead". Retrieved 2010-05-02.
  19. ^ "MaterialsScience". ReprapDocs. Retrieved 2007-02-15.
  20. ^ "Diamond Age Solutions". Retrieved 2006-06-04.
  21. ^ "Erik de Bruijn's Google Profile". Retrieved 2010-04-12.
  22. ^ "The Engineering Innovative Manufacturing Research Centre, University of Bath". Retrieved 2006-06-04.
  23. ^ "EPSRC Website". Retrieved 2006-06-04.
  24. ^ "Fluorocarbon Co. Ltd". Retrieved 2006-06-04.
Wikimedia Commons has media related to RepRap.

Project websites

Articles

Retrieved from "https://en.wikipedia.org/w/index.php?title=RepRap&oldid=359989696"