Back to the Future: The Making of the MakerBot Smart Extruder+

Forget a crystal ball, palm reading, or tarot cards. To see what’s on the horizon for desktop 3D printing, consider the past. In a recent interview with Actionable Intelligence, MakerBot’s CEO Jonathan Jaglom compared desktop 3D printing now to what he saw 10 years ago in industrial 3D printing at Stratasys. Though rapid prototyping was new then, customers sought more sophisticated 3D printing materials and features as their skills with the equipment developed. Jaglom finds that we are at a similar tipping point today: “As adoption gains momentum, designers and engineers are coming back to us and asking for more.” So what’s this have to do with the Smart Extruder+? Everything. We didn’t just redesign the Smart Extruder+ based on its predecessor’s performance. We collaborated with Stratasys and capitalized on our parent company’s 25 years of expertise and experience. Through that collaboration and the hard work of our engineers, we released an extruder that sets a new benchmark for quality. In this post, we’re going to understand why. We’ll dive into what’s new in the Smart Extruder+ and breakdown the significance of this collaboration.  

  Why Your Extruder Should Be Smart There are plenty of approaches to FDM extruders in the desktop 3D printing industry. However, in a classroom or office, there isn’t always time to troubleshoot an extruder by taking it apart or by going through complicated procedural steps with the 3D printer. To begin our design process, we stuck with the strengths of the previous extruder —its smarts. Sensors inside monitor critical points in the 3D printing process, like homing, leveling, and loading, unloading, or extruding filament. Each sensor provides real time feedback to your 3D printer, MakerBot Desktop, and MakerBot Mobile. These streamline the print process, save you time, and can even keep you from losing a print. To minimize downtime, pogo pins and strong magnets easily allow you to snap-on a new extruder when replacing an old one. Our Goals Beyond retaining a smart design, our major goals for the Smart Extruder+ were reliability, greater print success over a longer period of time, and a product that would last longer. To achieve these goals, the extruder went through a lengthy, carefully managed design process that lead up to a rigorous large-scale reliability demonstration test. That test was one huge gain from MakerBot’s collaboration with Stratasys, which we’ll explain in a few. What’s New To pass this massive test, plenty of blood, sweat, and PLA went into making sure each improvement to the Smart Extruder+ would achieve our goals. To do so, every new design tweak was built out then pushed to its limits in specific intensive tests. Imagine putting an extruder in a holder that’s horizontal to a table, pushing filament through it as fast as possible, and rotating it at the same time. Intensive. If a given refinement passed our performance and reliability requirements, we could move forward. If it didn’t, then our engineers would redesign and retest until it did. These major areas of improvement —drastically reduced filament jams, reduced clogging, and better connectivity— highlight the rewards of this process.  

  Drastically Reduced Filament Jams To drastically reduce filament jams, we overmolded the encoder wheel. This wheel closely monitors filament movement. It measures movement in small increments, as filament is pushed down by the drive gears and into the PTFE tube. If the wheel stops spinning, the filament jam sensor will pause the print and send you an alert. With this wheel, there needs to be enough friction so that filament will turn the wheel. If the wheel is too loose, it’s possible that filament will not touch the wheel. The wheel will not move in this instance, which will cause a false filament jam. Overmolding the wheel with soft plastic was key. It allows for the right balance of friction and give between the filament and top piece so that filament is passed through steadily and reliably. Reduced Clogging and Underextrusion To reduce clogging and underextrusion, we’ve extended the PTFE tube running from the hot end up to the drive gears. During the 3D printing process, the extruder melts the filament and lays it down on the build plate at a much thinner resolution than its original diameter. At the end of a print, between layers, and between different details, the extruder retracts filament. After retractions, filament will sometimes cool and harden. Because PTFE is a non-stick surface, molten filament doesn’t stick to it and build up. Buildups can result in clogs and underextrusion. Instead, filament slides off the tube and comes out of the nozzle. In addition, this tube is extended so that it runs along the entire path that the filament travels, keeping melted filament confined in one area. Otherwise, if this path features the slightest nooks or crannies, melted filament can harden and accumulate over time, causing a clog.  

  Better Connectivity To ensure better connectivity, the Smart Extruder+ is built with stronger magnets and longer pogo pins. We also added more gold plating. A stronger connection between the Smart Extruder+ and the gantry of the 3D printer minimizes the effect of vibrations during the 3D printing process. More vibrations can affect the accuracy of your print and rapidly wear down the pogo pins on the extruder, decreasing its life.  

  18-Years of Testing The entire model for the large-scale demonstration test was adapted from what’s been done at Stratasys. 119 extruders were tested in total across two locations by independent teams at MakerBot’s factory in Brooklyn and Stratasys’ corporate headquarters in Eden Prairie, Minnesota. In this test, the Smart Extruder+ performed consistently and reliably for more than 160,000 hours, making it MakerBot’s most tested product yet. That’s 18 years of testing. “The Smart Extruder+ underwent the most rigorous testing program that MakerBot has ever performed. Every aspect of the SE+’s development and testing program was thought out to ensure the most consistent and reliable product possible” says Jack Kinney, Senior Test Engineer at MakerBot.  

  As is worth noting, these extruders were built on multiple days by different line operators prior to the test. Beyond assessing the extruder’s performance, we needed to confidently know our assembly process is consistent and repeatable. The test also bore this out. Lasting 24 hours, our test print was designed to simulate customer usage. We designed it to test for reliability, print quality, and greater print success over time. While we cannot show the actual .stl file or a photo of the print, this test print assessed a huge variety of structures, such as overhang angles and domes, bridging, circles with tight and wide diameters, negative space tolerance, shapes with negative space on one side, raised and sunken text, as well as small sets of shapes. From Pilot Test to Data-Driven Production After this test, the Smart Extruder+ passed a short pilot-test phase and was cleared for serial production. During the pilot, we produced the first manufacturing lot on the production line and tested their performance. The results mirrored what we saw in our large-scale reliability demonstration test. Testing the function of every extruder in the factory is the last exhaustive step before they go out to customers. To ensure that the Smart Extruder+ performs as intended, we’ve implemented automated functional testers on the production line.  

  We collaborated with Stratasys’ test and automation engineers to build an “End of Line Tester” that thoroughly and quickly quality-assures extruders. Through a combination of custom-made hardware and finely tuned software, it conducts both basic and advanced tests on the build and electronics within the extruders. Extruders are compared against a huge array of metrics stored in a database. With this much data, we can pinpoint problems and even subtle weaknesses in a build and isolate any consistent issues cropping up on the product line.  

  The Future of Desktop 3D Printing The Smart Extruder+ is more than an end product. For us, it’s a commitment to quality that serves as a foundation for future breakthroughs. Reliability, superior performance, ease-of-use, longer lasting print success —these are all necessary stepping-stones to bigger advancements. Whereas desktop 3D printing is a young industry, we are poised to evolve in leaps and bounds without reflecting this youth. And here’s what makes this possible: our homegrown innovation and our collaboration with Stratasys, a leader in industrial 3D printing. For our customers, we aren’t just dedicated to providing the best possible desktop 3D printing experience. We’re redefining it.