Our project is to develop a new plastic extruder that can be fitted to existing 3D printers and will allow the 3D printers to print a number of types of thermoplastic beyond what is currently available. Our goal is to sell 100 of these extruders.
There are generally two types of thermoplastic that are available for filament type 3D printers, ABS and PLA plastics. These filaments are available in many colors and diameter sizes of 1.75mm & 3mm (0.070 & 0.118 inch). Currently these are pretty much the only sizes that can be used in these 3D printing machines. There are other types of thermoplastic available today that are available as an extruded filament however these have larger cross-sectional diameters of 0.125, 0.156 & 0.188 (3.18mm, 3.96mm and 4.76mm). These are sold as plastic welding rod and are typically used for joining sheets of plastic together. These larger diameter filaments come in many different types of plastic that have for the most part not been used by the 3D printing community. Many types of plastic welding rod are considerably less expensive per pound than the common printer filament of ABS and PLA. So if this material could be made to work in a plastic printer you could have a greater variety of plastics for printing and lower material cost. Our solution is to create a new extruder that can be fitted to existing 3D printers to enable these printers to use all of these different diameters of filament and handle the wider range of processing temperatures for the different thermoplastics.
We have already built 3 versions of our NEMA 23 extruder so far with improvements being incorporated to each new version. We have run the extruders with various materials and are convinced we have a good product here. Our plan is to manufacture our extruders in two sizes. A large extruder driven by a NEMA 23 stepper motor and a smaller version driven by a NEMA 17 stepper motor. The larger version will be able to run all of the filament sizes from 1.75mm to 4.76mm (0.070 to 0.188 inch). The smaller version will run filament sizes 1.75mm to 3mm (0.070 to 0.118 inch). The heater block of our extruders and the nozzles are made from copper for faster and more stable temperature control. Several nozzle sizes will be available for printing various sizes and types of parts.
Our latest version of this extruder is larger than current extruders and has design improvements to allow it to take advantage of the higher temperature ranges required by the various types of thermoplastic available in the larger diameter sizes. These plastics have properties that will greatly enhance a 3D printer's usefulness by allowing it to make parts that can be used in many different environments.
The following are some of the types of common thermoplastic welding rod along with several uses and properties that would make them an attractive candidate for a 3D printed part.
PVDF Chemical restiveness of PVDF and its long lasting strength will make this a popular choice for laboratories or clean-rooms where tanks, tank furniture, fittings or cassettes could be made quickly from a computer library of components or as needed from a 3D CAD drawing for a custom application.
PVC 1, PVC 2 & CPVC with their ability to withstand UV would be great for any sort of outdoor applications or unique PVC pipe fittings. These materials also resist acids and alkalies and are commonly used in chemical processing applications.
Polypropylene makes parts with a hard surface and resists many chemicals and solvents. One interesting use for this material is its ability to make parts that have a living hinge on them, like used on the lid of a Tic-Tac candy box. It is also commonly used in clean rooms for chemical benches, tanks and enclosures.
Polyethylene available in low or high density formulations are very resistant to moisture as well as many chemicals.
HMW makes parts with a slippery surface useful for many industrial applications such as chain guides or rollers. It has excellent impact strength and good wear resistance.
Polycarbonate is synonymous with impact resistance. This transparent material has excellent impact resistance over a wide temperature range. Parts made from this plastic would have great strength and flexibility.
Our extruders, are of course, not limited to these materials and can also extrude ABS, PLA, any of the Taulman filaments, nylon, PETT, HIPS, PVA and others from 1.75mm diameter to 4.75mm diameters (0.070 to 0.188 inch). Many of these materials have previously not been available to the 3D printer community. It is our hope that this extruder will change that and be a benefit to all 3D printer owners who need parts with better strength, chemical resistance, UV resistance or other properties that these various plastics can provide.
Beyond the end user capability to run a greater selection of plastic materials , we believe our extruders are simply the best designed and best performing extruders available today. They feature a compact, light weight, solid one piece aluminum frame with integrated centrally placed heat sink for maximum cooling of drive components and stepper motor. The extruder uses two spring loaded driven hobbed wheels to grab the filament providing the surest grip to the material. Our units are directly driven by stepper motor for zero backlash, fast and strong transfer of filament. Our extruder can lift 12 pounds via a piece of filament before the stepper motor stalls. The drive wheels never slipped during this lift test. Our extruders can be mounted from top, bottom or either side surface to make adapting it to your 3D printer an easy task.
Why are we so proud of our extruders?
- Very compact design with a mid mounted, integrated heat sink for better cooling of both filament drive parts and stepper motor.
- Extremely solid one piece aluminum body with mounting options on top, bottom or either side.
- Copper heater block and nozzle for faster, more stable temperature control.
- Plans for making two sizes of extruder, a NEMA 17 stepper motor size for smaller 3D printing machines or the larger, more powerful NEMA 23 stepper motor extruder for larger, faster moving 3D printers.
- Precision quality, our extruders feature a spring loaded dual wheel filament drive mechanism for positive filament control. The drive wheels are made from steel and are hobbed for traction.
- Our NEMA 23 extruders will be able to accommodate 5 filament sizes (1.75mm, 3mm, 1/8, 5/32 and 3/16 inch diameter filaments) and multiple plastic options with nozzle options for various materials and extrude diameters.
We plan on performing all of our own manufacturing at our facility in Nampa, Idaho where we have several CNC machine tools for this production. The parts and materials to build these extruders are mostly sourced. We will be ready to go into production on the schedule we have planned. We are confident that this project is going to be a big success and we ask those of you who are 3D printer users, 3D printer OEMs or simply have an interest in 3D printing to please join us by making a generous pledge towards our 3D printer extruder project! Don't forget to tell your 3D printer friends about our Kickstarter project!
Risks and challenges
Problems to overcome:
One issue with the new plastics will be the materials ability to stick to the stage (or rather the tendency to not stick to the stage) and this will be something that will need to be worked out. We already have this solved for some of the materials.
Ideal extruder temperatures will need to be learned for all of these materials. Some may require a heated stage.
We are planning to experiment with different nozzle sizes for larger printed objects. This will require some trial and error while we discover best sizes for each material.
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We believe all of these issues can be dealt with and that this project will be a great success. Please join us with a generous pledge towards our project.