Rapid Prototyping Laboratory

Mechanical Engineering, Virginia Tech

Director: Prof. Jan Helge Bøhn

Rapid Prototyping Laboratory:

	Faculty
	Research Activities
	Laboratory Equipment
	Industrial & Government Partners
	Rapid Prototyping Education

Return to:

	The Rapid Prototyping Resource Center
	Jan Helge Bøhn
	Mechanical Engineering at Virginia Tech

Revised: February 19, 1998
http://cadserv.cadlab.vt.edu/bohn/rp/

Faculty

• Jan Helge Bøhn, Mechanical Engineering
• Donald G. Baird, Chemical Engineering
• Ronald G. Kander, Materials Science and Engineering

Research Activities

Improved System Throughput and Accuracy

• Estimated peak speed improvement potential with sustained geometric accuracy: 120 times faster than current commercial methods.
• Current results: 500% increase in actual fabrication speed of fused deposition modeling (FDM 1600) has been demonstrated without reducing part surface quality.
• E. Sabourin, "Adaptive High-Precision Exterior, High-Speed Interior, Layered Manufacturing," M.S. thesis, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA, February 1996.
• E. Sabourin, S. A. Houser, and J. H. Bøhn, "Adaptive Slicing Using Stepwise Uniform Refinement," Rapid Prototyping Journal, vol. 2, no. 4, 1996, pp. 20-26.
• E. Sabourin, S. A. Houser, and J. H. Bøhn, "Accurate Exterior, Fast Interior Layered Manufacturing," Rapid Prototyping Journal vol. 3, no. 2, 1997, pp. 44-52.

Fundamentally New Rapid Prototyping Process

• Fabrication of parts with continuously changing material composition throughout a part in all three dimensions.
• S. Fitzgerald, "A Pneumatic Conveying Powder Delivery System For Continuously Heterogeneous Material Deposition In Solid Freeform Fabrication," M.S. thesis, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA, July 1996.

Advanced Materials

• Thermoplastic fiber composites
• Soft elastomeric materials (72 Shore A)
• Soft elastomeric materials gradually blending into strong, stiff thermoplastic components.

Geometric Modeling for Engineering Design and Analysis

• Development of high-speed, high-accuracy analysis technologies for casting (e.g., shrinkage, solidification) and metal-ceramic brazing.
• Fabrication and manipulation of CAD models extracted from industrial and medical imaging systems (e.g., MRI and CT data):
  • Fabrication of parts directly from scanned data without intermediate CAD models, to provide more accurate parts with less approximation
• Visualization applications:

  Inducer for a liquid hydrogen rocket pump. Designed by Rocketdyne. Full-size image: 403,453 bytes

Laboratory Equipment

Hardware

• FDM 1600 rapid prototyping system
  Fused Deposition Modeling (FDM) from Stratasys, Inc.
  Builds parts using ABS plastic, nylon, or investment casting wax.
• 3000 VA Uninterruptible Power Supply (APC Smart-UPS 3000 NET)
  Provides continuous power for FDM 1600 and SGI Octane.
• Vacuum Oven (Fisher Scientific 282A oven, Edwards E2M2 2cfm pump)
  For drying materials prior to use; provides consistent, superior part quality.
• SGI Octane workstation
  IRIX 6.4, 128 MB RAM, 728 MB swap, 22 GB hard disk
  SI graphics: 1.26 M triangles/sec, 195 MHz R10000, SPEC-95: int=11.0, fp=17.0
• HP 735 workstation
  HP-UX 9.03, 288 MB RAM, 600 MB swap, 3 GB hard disk, 4mm DAT (2 GB)
  CRX24 graphics: 0.175 M triangles/sec, 99 MHz PA-RISC 7100, SPEC-95: int=3.27, fp=3.98
• Additional disk space
  2 GB reserved on VT CAD Laboratory server.

Software

• Automatic CAD model repair utilities
• Stratasys: QuickSlice 6.0
• SDRC: I-DEAS Master Series 6.0
• PTC: Pro/ENGINEER
• Dassault: CATIA

Additional Equipment Available for Rapid Prototyping Research

• Virginia Tech Computer Aided Design Laboratory
  • IBM RS/6000 model 980 server
    512 MB RAM, 25 GB hard disk.
  • 18 IBM RS/6000 model 41W workstations
    128 MB RAM, 4 GB hard disk, 24-bit Gt4xi graphics.

• Chemical Engineering Laboratories
  • Complete materials fabrication and processing analysis capabilities.

• Materials Science and Engineering Laboratories
  • Complete materials characterization capabilities.

Industrial & Government Partners

	NSWC/DD: Naval Surface Warfare Center, Dahlgren Division
	Armstrong Laboratory Brooks Air Force Base
	Stratasys, Inc.

Rapid Prototyping Education

ME 4644 Introduction to Rapid Prototyping
Participants will study topics fundamental to rapid prototyping and automated fabrication, including the generation of suitable CAD models, current rapid prototyping fabrication technologies, their underlying material science, the use of secondary processing, and the imapct of these technologies on society. The rapid prototyping process will be illustrated by the actual design and fabrication of a part. Co: ME 4634 or equivalent CAD system experience.
Offered every spring semester since 1995.
Limited enrollment. Approved as ME Technical Elective. Approved for Graduate Credit.

EF 1005-1006 Introduction to Engineering
Introduction to the College of Engineering and the profession; departmental orientations, professionalism. Problem presentation; lettering, sketching, engineering calculations. Technical library research. Digital computer applications; DOS, word processing, FORTRAN, elementary numerical methods. Engineering graphics; orthographic projection, rotation, conventional practices, computer graphics. For engineering students only. Co: MATH 1205. 1005: (3H,2C); 1006: (3H,3C). I,II,III.
Rapid prototyping was introduced on an experimental basis in EF 1006 during the Spring 1996 semester, using AutoCAD R13 and a FDM 1600 rapid prototyping system.