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OSHE High Temperature 3D Printer
High Temperature 3D Printer for Open Source Hardware Enterprise
Senior Design project developed by Aubrey Woern and Daniel Scsavnicki
To provide a low cost, open source solution for 3D-printing in high performance materials such as PEEK (polyether ether ketone), PEI (polyetherimide) and PC (polycarbonate), to increase the availability to engineers, makers and medical professionals to print in these materials.
Materials such as PEEK and PEI, have many benefits over traditional 3D-printed polymers like PLA (polylactic acid) and ABS (acrylonitrile butadiene styrene). One obvious advantage to using high performance polymers is when the final parts need to be heat resistant. PLA has a continuous use temperature of around 50℃, while PEEK can withstand temperatures up to 260℃. The other advantage of these types of polymers is when high strength, end-use parts are required. Currently, desktop 3-D-printing is adequate for creating functional prototypes with the only limiting factor being the strength and durability of the current material selection. With PEI having double the tensile strength as ABS, parts can finally be printed with the strength required for many more end use cases. 3-D-printing with high performance materials such as PEEK or PEI has been prohibited to only large corporations due to the need for expensive, proprietary 3-D printers. To print in these materials, the hotend, which melts the polymer for deposition, needs to be able to reach temperatures of over 400℃. Also required for successful printing are; a fully enclosed and heated build chamber, an all metal tool-head, and active machine cooling. These professional machines cost between $10,000 to $250,000 and often need proprietary software to run them. The benefit of 3-D printing on desktop machines is that they have most of the functionality of the professional machines, for less than $1000. What they have lacked up to this point has been the inability to print in high temperature plastics. Many desktop 3-D printers have a maximum temperature of 290℃ because of their temperature sensors, and plastic components on the hotend. They often lack heated chambers and heated build plates as well.
The goal of this project is to build a desktop level or RepRap 3-D printer that can 3-D pPrint high temperature plastics using low-cost components.
The main goal of the project is price reduction, the target is to make a 3-D printer for less than $1000, which would then lower the barrier to entry for many industries. Some examples of industries that would benefit from this would be: medical, manufacturing and aerospace. Hospitals could 3-D print custom instruments and tools in PEEK (an autoclave safe plastic) making the tools usable in sterile environments while being reusable. For manufacturing, 3-D printing could now be used to make end of use parts instead of just proof of concept builds. Another use for manufacturing would be to use high temperature plastic to make low run injection molds; helping reduce the cost and lead time for parts that can be better manufactured in the molding environment. Finally, aerospace companies are starting to cut costs by switching from machined aluminum to 3D Printed high performance polymer parts. In every use case listed, the goal is to reduce operating costs and allow more people to use it.
- Increase the maximum temperature of the 3-D printer’s tool-head
- Using an all metal hotend with thermocouple, an aluminum mounting fixture and insulated filament extrusion assembly.
- Reach a hot-end extrusion temperature of 400℃
- This will allow immediate extrusion of PEEK, the highest melting polymer available.
- Build a fully enclosed, heated build chamber, and mount around existing 3-D printer frame
- Using insulation, heat lamps, resistance heaters and fans to create a low cost design for the chamber
- Using thermodynamic analysis, find optimum locations and power levels for heaters, and best insulation for the price
- Reach an ambient enclosure temperature of 100℃
- Many semi-crystalline plastics tend to warp immediately after printing due to rapid cooling, a heated chamber will slow cooling rates and warping to provide an overall stronger and more accurate part
- Verify mechanical strength of printed parts versus industrial 3-D printers.
- 3-D print tensile and compression test samples and test to ASTM standards
- Tensile strength must be within 10% of industry standards for each plastic
- Once the new 3-D printer is verified to print strong parts, we can begin case studies
- Verify machine usability by printing three case study parts and testing in real world conditions
- A medical device or instrument that can be subjected to an autoclave for sanitizing
- An injection mold that can be used over 25 times to make low-run parts
- An end-use part that needs to be strong and heat resistant.
- Finally, find ways to reduce costs further by upgrading the 3-D printer
- More efficient or lower cost heating elements
- 3-D printing directly from pellets that are orders of magnitude less expensive than buying filament.
Bill of Materials
- MOST Delta RepRap or similar RepRap 3-D printer
- Allen Wrench (For M5 and M3 Bolts)
- Soldering Iron and Solder
- Mini Screwdriver Set for Ramps Board Terminals
- Square and Level
- File Set for Finishing parts if needed