Prusa i3 is one of the most popular constructions of RepRap 3D printers in the world. It has a lot of modifications. Now it is time for changes of the original one. What new did Josef Prusa create?
The newest version of Czech 3D printer is called Prusa i3 MK2.What has been changed?
First of all, it is 250×210 mm, so about 30% bigger. Secondly, cold corners were eliminated. After analysing with a thermal cam, it was claimed, that a difference of temperatures between middle and edges of working platform could have amounted even 15ºC. The final design uses three power zones where the corners heat couple °C more than the center to form warm air shield at the edges of the print bed.
The next change was eliminating glass from the surface of working bed, because it was assembled to obtain a perfect surface of the first layers, but it didn’t change adhesive stamps of the platform, so Prusa decided to find an alternative. He tried with velvet polycarbonate film (BuildTak) which was no good. It is very easy to damage the thing and fuse object to it permanently. He considered also kapton, but it made a comeback on some printers so we decided to test it too, but it is still too easy to tear and degrades over time. Ultem PEI turned out to be a perfect material. It is very resistant – you can even crash fully heated nozzle into the surface without damaging it.
Custom motors manufactured with integrated trapezoidal lead screws and prevent moving of Z axis and ensure better layer alignment. Thanks to that axis got also way faster and more wear resistant which leads to possibility of using Z Lift where the nozzle lifts up on travel moves and prevents scarring (leaving unpleasant mark on already finished layer, by dragging the nozzle on top of it).
The most wanted feature, which was also the most problematic for its creators. At first Marlin has to be rewritten. The next point was to develop 9 specialised calibration points on the bed substrate to get great repeatability. As it turns out, you can’t just use induction probes on normal PCB heated beds.
Frame stability was improved in place of connection between the main frame with Y axis. The bed is now completely bolted to the Y carriage with classic corner screws and two more in the centre. A new casing of electronics is equipped with a door, what makes it more accessible and LCD cover has been radically improved too, mainly to easily guide the SD card into the slot.
Nozzle E3D V6 Lite was replaced with E3D V6 Full. Thanks to that it is possible to print quicker and heat it to 300ºC, what gives you a possibility of using new materials, which require higher temperatures.
The newest version of Marlin was implemented, which enables carrying out of an autotest of a 3D printer, immediately after assembly. It is additionally able to diagnose itself after you finish building it and guide you to fix the problems on it’s LCD!
The 3D printer has provided profiles suitable for the most popular slicers on the market, like: Slic3R, Cura, Simplify3D, Kisslicer. Profile for Slic3r have settings proper for 12 different materials.
All of the users, who own an older version of Prusa i3 and electronics Rambo Mini, can buy an upgrade kit, for about 222 €.
Original Prusa i3 MK2 kit is currently available for preorder for 699 USD (or 739 EUR with VAT) and will be shipped very soon.
Source: www.prusaprinters.org