Mark2 is an asymmetrical multi-extrusion upgrade for the Ultimaker 2, based on Foehnsturm's magnetic tool changer. It offers some unique features compared to conventional approaches.   Keep it smart and simple The Mark2 upgrade doesn't require to modify or even disassemble the well-working single extrusion setup. Instead it adds a detachable second extruder. This leaves you with several benefits. Powerful - print quality on par with eg. the UM3 or BCN3D Sigma Flexible - use whatever you want: Olsson ruby, 3Dsolex block / nozzles, ... Cost-efficient - all you need is a second drive train, some magnets and screws Simple - all tried-and tested standard components Smart - Z-offset managed by firmware, calibration wizards Open & scalable - a non-extrusion tool head, a 3rd extruder ... all possible Mark2 is an Ultimaker community project, we don't offer a complete kit but we can help you out with a package, including all the parts you need, besides the second drive train.   See it live Probably the best way to get an impression of the usability and print quality is to watch a few videos. https://www.youtube.com/watch?v=PLeNzDYMnqAqIeZHWU9iOWnj_2OaemupQG   Full Cura 2.5 integration Mark2 comes with a set of Cura definition files and can be added as a pre-configured printer.   Tried and tested Mark2 setups have been printing for more than 5.000 hrs now, which equals more than 500.000 tool changes. Beta-testers and co-developers include well-known guys here like Tinkergnome, Ultiarjan and many more.   The Mark2 website ultimaker-mark2.com is the place where you find all the information you need for doing this upgrade. ... and The Mark2 Dual Extrusion Project Contest is still running.