The 3D Printers or rapid prototyping tools are machines which produce a 3-dimentional solid object from a digital 3D model. Our 3D printers use additive layer manufacturing to produce models. We have several different types of printers here. Eight use the FDM (fused deposition modeling ) process, which is extruding a heated plastic filament of PLA or ABS and fusing the layers together. One has a wash-out support. There two experimental resin printers, one SLA (Stereolithography) that cures layers of resin with a photo laser, the other has a UV digital light projector to cure resin, this uses software that translates your geometry into .png files. Also we have now a ZCorp powder printer, using adhesive to bind silica powder into a shape. Printed layers of material are created by the printer by following a set of instructions (gcode) (.stl file extension) from the software to slice a 3D model into layers, then building up those layers until it creates a complete printed 3D model.
Costs are $.10 a gram for basic printing. The Dimension printer- 1200es (Lexus) has a 10" cubed build area, it is printing with a ABS and a washout support structure (Cost is $.25 per gram for CAPLA students only). For UofA students and Faculty outside of CAPLA, the costs are $10 a cubic inch. The 8 other printers using PLA or ABS with an approximate 9x6x6" build area.
To submit a 3d printing file, fill out this form here:
Dimension Wash-out Tank Instructions:
The cleaning solution in the bath for the dimension prints contains sodium hydroxide which can cause severe burns to eyes, skin and respiratory tract. Proper PPE is required. See instructions posted at the bath. Proper handling is solely the responsibility of the user.
· Do not operate the unit unless authorized to do so.
· Always wear safety face shield eye protection, rubber apron for your clothes and rubber gloves when working near the unit.
· Turn power to unit off.
· Remove lid and place on provided lip right in front of control panel
· Raise the cleaning basket out of the tank and rest on support/guide pins
· Place parts in appropriate stainless steel basket. Use small square basket with latched door for smaller parts and put in larger basket.
· Slowly lower the large basket into the tank.
· If fluid level indicator light comes on and more water to tank until it turns off.
· Never operate tank unless the liquid level is above the liquid level low mark on the rear wall of tank.
· Place lid back on tank
· Press set button to set time, use arrows to raise and lower time
· Press start cleaning cycle
· Cleaning time is based on size of part and cleaning solution condition.
· If solution is too dirty to clean any longer ask monitor to change.
Useful Rhino to 3D printing .STL output tips: http://isites.harvard.edu/fs/docs/icb.topic907832.files/Tips%20for%20Users%20of%20Rhino.pdf
Other local sources, to compare costs, available for 3d printing:
Microsoft on-line repair tools for meshes:
The lab has had great success with AutoDesks' MeshMixer to repair and alter meshes for 3D printing and it's free.
Digital Input Devices
The lab has a MicroScribe-3D Desktop Digitizer. This device allows complex geometries to be entered directly into 3D digital files.
Instron Testing Machine
Tensile strength measures the force required to pull something such as rope, wire, or a structural beam to the point where it breaks.
There are three typical definitions of tensile strength:
- Yield strength - The stress a material can withstand without permanent deformation. This is not a sharply defined point. Yield strength is the stress which will cause a permanent deformation of 0.2% of the original dimension.
- Ultimate strength - The maximum stress a material can withstand.
- Breaking strength - The stress coordinate on the stress-strain curve at the point of rupture.
Units or how to measure
- Young's modulus is the ratio of stress (which has units of pressure) to strain (which is dimensionless), and so Young's modulus has units of pressure. Its SI unit is therefore the pascal (Pa or N/m2 or m−1·kg·s−2). The practical units used are megapascals (MPa or N/mm2) or gigapascals (GPa or kN/m2). In United States customary units, it is expressed as pounds (force) per square inch (psi). The abbreviation ksi refers to "kips per square inch", or thousands of psi.
Compressive stress and strain are calculated and plotted as a stress-strain diagram which is used to determine elastic limit, proportional limit, yield point, yield strength and (for some materials) compressive strength.
The flexure test method measures behavior of materials subjected to simple beam loading.
Types of Flexure Tests
Flexure testing is often done on relatively flexible materials such as polymers, wood and composites. There are two test types; 3-point flex and 4-point flex. In a 3-point test the area of uniform stress is quite small and concentrated under the center loading point. In a 4-point test, the area of uniform stress exists between the inner span loading points (typically half the outer span length).
SET-UP of INSTRON TESTING Manual
How to plot data in MS Excel
- You must first save all data as a .TXT file. It should be set up to save as a .TXT file but if it is not, open the test method, click on the main tab, go to global parameters, and check the box that says “ASCII Test Data File.”
- Run the test after setting up your test parameters, Scale, Units, etc, in the Main Tabs and save to the desktop or a flash drive. NO internet connection!
- Transfer data to computer with Excell and open .TXT data file.
- Hit file, open “all .TXT files” select your file.
- You will go through the import wizard to bring your file in to Excell.
- There should be 3 columns of data depending on how you set up your data collection. Data, Data point #, and time of the data point.
- To graph, select the time and data point. Then go to “insert”, chose “line” then chose “stacked Line”.