Tag Archives: SLS Printer

bioengineers

This modified laser cutter can print complex 3D objects from powder


Rice University researchers have modified a commercial-grade CO2 laser cutter to create OpenSLS, an open source SLS platform.


Engineers at Rice University have modified a commercial-grade CO2 laser cutter to create OpenSLS an open source, selective laser sintering platform that can print complicated 3D objects from powdered plastics and biomaterials.

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As impressive as that may be, what really sets this system apart is its cost. OpenSLS can be built for under $10,000, compared to other SLS platforms typically priced in the ballpark of $400,000 and up. (That’s at least 40 times less than its commercial counterparts.) To make this a reality, this DIY device is equipped with low-cost hardware and electronics, including Arduino and RAMBo boards. The Rice team provides more detail around specs and performance in PLOS ONE.

“SLS technology is perfect for creating some of the complex shapes we use in our work, like the vascular networks of the liver and other organs,” explains Jordan Miller, an assistant professor of bioengineering and the study’s co-author. He adds that commercial SLS machines generally don’t allow users to fabricate objects with their own powdered materials, which is something that’s particularly important for researchers who want to experiment with biomaterials for regenerative medicine and other biomedical applications.

To test their concept, the team demonstrated that OpenSLS is capable of printing a series of intricate objects from both nylon powder — a commonly used material for high-resolution 3-D sintering — and from PCL, a nontoxic polymer that’s typically used to make templates for studies on engineered bone.

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It should be noted, however, that OpenSLS works differently than most traditional desktop 3D printers, which create objects by extruding melted plastic through a nozzle as they trace out two-dimensional patterns and 3D objects are then built up from successive 2D layers. On the contrary, an SLS laser shines down onto a flat bed of plastic powder. Wherever the laser touches powder, it melts or sinters the powder at the laser’s focal point to form a small volume of solid material. By tracing the laser in 2D, the printer can fabricate a single layer of the final part. After each layer is complete, a new one is laid down and the laser is reactivated to trace the next layer.

The best way to think of this process, says Miller, is to think of “finishing a creme brulee, when a chef sprinkles out a layer of powdered sugar and then heats the surface with a torch to melt powder grains together and form a solid layer. Here, we have powdered biomaterials, and our heat source is a focused laser beam.”

The professor, who happens to be an active participant in the burgeoning Maker Movement, first identified commercial CO2 laser cutters as prime candidates for a low-cost, versatile SLS machine three years ago. According to Miller, that’s because the cutter’s laser already possessed the right wavelength and perfectly suitable hardware for controlling power and its axes with precision.

Intrigued? You’ll want to see it in action below, and then head over to the team’s Wiki page and GitHub repository to delve a bit deeper.

[Images: Rice University]

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Sintratec unveils the world’s first desktop laser sintering 3D printer

Swiss startup Sintratec has officially taken to Indiegogo to unveil its new desktop SLS 3D printer, the world’s first of its kind.

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Earlier this year, Sintratec had announced that they were developing a new SLS 3D printer that would be priced in the ballpark of $5,000. Now, the startup has launched a crowdfunding initiative around their new device, whose early bird model will set you back just $4,000 — an amazing price when compared to similar printers. With the Sintratec 3D printer campaign up and running, the team hopes to sell about 60 ready-to-assemble units.

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Based on an Atmel ATSAM3X8E, the SLS 3D printer will feature a build volume of 130x130x130mm, along with a 500W optical heater, a 2300mW, a 1200W heating coil and a chamber temperature of 150°C. In addition to the 32-bit Atmel | SMART MCU that comes packed with the startup’s own custom firmware, the Sintratec electronics will enable a wide-range of functionality including the ability to:

  • Drive each of the motors necessary for printing, as well as the scanner system and the laser.
  • Control the powder surface temperature using an optical heating system with infrared sensor feedback.
  • Command the chamber temperature using the heating coil with thermistor feedback
  • Run a composite-device mode via USB for communication with the Sintratec software. (At the same time, an SD-card on the electronics board is accessible to users as a mass storage device. For instance, you can store print-jobs on the SDcard for later use with different computers. Not to mention, once you have started a print, you can disconnect the USB.)

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For those unfamiliar with selective laser sintering (SLS), this form of 3D printing uses a laser as the power source to solidify and bind a powdered material (typically metal) together by aiming the laser automatically at points in space defined by the required 3D model a user would like to create. In addition, unlike common 3D printers, this method does not require support structures.

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As a result, Sintratec uses unsintered powder to build new layers on top of one another, which enables a Maker to print overhands, stacked objects, undercuts, hollow shapes and more — all with no additional support.

The desktop unit will print objects in a nylon called PA12 and can produce both functional prototypes and end products, including designs with moving parts.

Even better, the team writes, they are “actually printing with the same quality powder used by machines which cost over $200,000. It is extremely durable, strong and at the same time flexible enough to prevent brittleness. Because the powder is sintered together, the final parts have a high mechanical load capacity in all directions and are not suffering from the weak bond between layers as is the case with filament printed parts.”

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Testament to the tremendous demand for the innovative machine, the team has garnered a number of awards such as 1st place (among 250 startups) at this year’s Swiss UpStart Challenge as well as an honorary mention by MAKE: Magazine as a printer to watch in 2015.

Those interested in learning more or backing this incredibly unique printer can head over to its official Indiegogo page here. With weeks remaining in the campaign, and having already attained 65% of its pledge goal, let’s just say we are quite optimistic! If all goes to plan, the team expects to begin shipping the first batch of machines mid-summer 2015.