bondtech extruder

thingiverse

Eric Lien created a new and wonderful design to be found at http://www.bondtech.se. A planetary box can be used, as seen at http://www.thingiverse.com/thing:1321364. "I've been involved in 3D printing for two years," says Eric Lien, "and one of the biggest problems I've encountered is related to material feeding." The extruders currently available use a single driven wheel with a spring-loaded bearing that pushes the filament against the drive wheel. However, this method has some significant disadvantages. For example, it has low pushing force, which can lead to failed prints. It also risks grinding the filament, which can result in a failed print. Furthermore, slipping occurs frequently, leading to underextrusion. Additionally, deforming the filament increases friction in the bowden tube, making it difficult to extrude. The new Bondtech extruder uses two drive wheels equipped with sharp teeth that grab the filament on both sides. This gives a number of advantages over standard extruders. Some of the most important ones are: Firstly, the huge pushing power eliminates the risk of underextrusion. Tests have verified that it is over 9 kg with a 1.75 mm filament. Secondly, there is minimal risk for filament grinding. Thirdly, high-speed printing is possible due to the big pushing power. Tests have been made with 250 mm/s printing with a 0.4 mm nozzle and no filament grinds. Fourthly, it's possible to use small nozzles. Fifthly, the high-torque Nema17 stepper with a high-precision planetary gearbox provides high resolution and fast retracts. Lastly, the secondary drive wheel is adjustable, allowing for optimized grip. A walkthrough of the design by Eric Lien can be seen at https://youtu.be/18dc96ZMd2I. In addition, he has shared more information on Google+ at https://plus.google.com/109092260040411784841/posts/gnn6rmyWWC6. In a few weeks' time, kits with metal parts and professional 3D printed SLS parts for housing components will be available. The current version supports only 1.75 mm filament but a 3.0 mm version is in development. The bill of materials includes: * Front housing * Rear housing * Logo plate * Nema17 stepper with 5:1 planetary gearbox * Bondtech large drive wheel * Bondtech small drive wheel * Two 5x10x4 ball bearings * Two MC6S M3x16 socket screws * Two MC6S M3x40 socket screws * Two M4 nuts for securing the bowden tube * Bowden tube (4x2.0 mm)