The Rapid Lab Facilities
An important part of the intensive MEES undergraduate design curriculum is the generation of physical, working models to meet the design specifications for each project. Students may use the Machine Shop and the Rapid Lab to create these models. Our Rapid Lab is used by our students to complete complex models from their design projects throughout the curriculum. Initial three-dimensional solid models are created using CAD software. Primary training in CAD incorporates Pro/Engineer® from PTC® during our Freshman and Sophomore design courses. Students also have access to SolidWorks® from Dassault Systèmes for optional use later in the curriculum. Additionally, our students have access to three-dimensional scanners for reverse engineering.
- Three Dimensional Scanners
- Roland _____
- Rapid Prototyping Systems
- Fuse Deposition Modeling (FDM)
- 3D Printing
- Engineering Design & Analysis Software
- 3D modeling (e.g., Pro Engineer and Solidworks)
- Analysis Software (e.g, Abacus, ANSYS, ANSYS CFX, LS-Dyna, COMSOL, etc..)
Today, engineers use multiple forms of Additive Manufacturing. Traditionally this technology was called Rapid Prototyping but with improvements in machine speed, material strength and part accuracy the systems are actually being used for manufacturing. Presently we use two Fused Deposition Modeling (FDM) machines from Stratasys® and one three-dimensional printer (3DP) from ZCorporation®.
To create a Rapid model three dimensional models must be transferred to the pre-processing software in a generic format. The most common format is an STL file (STereoLithography). This file format was created by Charles Hull for 3D Systems to allow three dimensional geometric models to transfer from any CAD system. This method takes the original model and breaks it up into small planar facets. For planar or cylindrical surfaces, the edges are broken into points and points are used to create triangular facets. Free form surfaces are broken into a point cloud before faceting.
This technology uses a solid filament of the build material to build a model layer-by-layer. In this machine, the filament passes through a heated nozzle to a molten state and then deposited in layer by layer to build the model. The machines we use have a form of ABS (acrylonitrile butadiene styrene) polymer for model generation and a proprietary support material is deposited through a second nozzle to create a support structure while the model is being built. Other machines are manufactured by Stratasys that allow additional materials.
ZCorp 510 -- Three Dimensional Printing (3DP) (This system was purchased in conjunction with the Center for Biomedical Engineering Systems)
The Three Dimensional Printing uses a binding agent applied to a mechanical base to create models. The machine in our Rapid Lab uses a plaster base powder and liquid binder to create a physical model. Our machine has four color binders to allow full color models. Model creation is fast but the physical models are weak directly from the machine. Secondary binders greatly increase the strength of the models but add an additional level of process requiring full time user interaction which may greatly increase the time and cost of model completion.
3D Printing Process
Courtesty of Dr.Jeff Raquet - MEES, UNC Charlotte