This is a moment when Joseph Prusa, a godfather of 3D printers with the kinematics named after him, released a 3D printer with a CoreXY kinematics. But his team isn’t planning to move away from an older solution. In this article we will talk about what the Original Prusa XL will look like, as can be seen in the pictures from the Formnext 2021 exhibition.
The new machine has a build volume of 360 x 360 x 360 mm. According to Josef Prusa, the large size was the reason to go from the classic Prusa kinematics to the CoreXY. The platform of this size that is movable over the Y-axis would be rather heavy and the Z-axis rigidity would be more difficult to achieve. So there was no point in scaling up the Original Prusa MK3. .
The Original Prusa XL features an interesting print platform that consists of sixteen elements that are tightly placed side to side. They are sized 90 x 980 mm each and have individual heating components. There are two reasons for this: the first is that it allows for zoned heating that makes it possible to turn down some elements and save electricity when printing small objects. The second reason: it helps to avoid thermal deforming. A replaceable flexible print plate is placed atop of it.
The same platforms are used in the 3D printing farm presented at the Dubai Expo 2020 but those featured nine segments instead of sixteen. And if sixteen ones are possible, there’s nothing to stop Prusa from using even more. Josef Prusa didn’t say anything about that but there are chances that the Prusa XXL, as well as XXXL can see the light of the day some time in the future.
The extruder has been completely redone, it now features a powerful cycloidal reducer with a gear ratio of 20:1. There’s also an easily replaceable hot-end. The structure is quite lightweight despite the use of a direct-drive extrusion system. That means that there will be a high positioning speed and levels of accelerations. But nobody knows the exact numbers yet, even Josef: his team still continues testing, as well as firmware development and setting up the needed parameters. There’s also a chance that there will be an option to get the Klipper firmware — it will be an official offer but will lack tech support.
It’s obvious that even at the fastest speeds printing larger objects will take days.so the manufacturer decided to stop at the functional build volume of 360 x 360 x 360 mm. Prusa mentions that the design is focused on quality and reliability of printing. The speed is important, of course, but reliable operation is worth more.
Obviously, the device will feature a filament runout sensor and the print resume function which can be life-saving in the case of power outage or if one needs to change filament mid-print. Telescopic tube fasteners can hold the spools weighing up to 3 kg, so the filaments will last quite long. The model that was shown to the public has an open structure but Josef Prusa promises that the enclosure can be installed, or even a lid for a more stable ambient temperature.
The leveling is automatic and the system uses a strain gauge. The latter is located inside a radiator of a thermal barrier and Prusa says that it can help putting the first layer on nearly anything. The system automatically tracks unevenness on the print plate and compensates it while putting the first layer. Replacing the hot-end or the nozzle doesn’t require Z-axis calibration afterwards: Another advantage is that the gauge can track how filament is pushed through the system and stop the process if anything goes wrong. The team is even testing the ability to predict nozzle blockage or ruptures during print removal. There’s an additional thermistor that can track heating of cold areas that cause the clogging.
And one of the most interesting feature is an option to install automatic extruder replacement technology with five printheads. Everything is done mechanically without the magnets in order to provide better reliability. The calibration is done using the aforementioned strain gauge. According to Josef Prusa, during testing the system did more than 500,000 cycles with any issues.
Five interchangeable print heads provide many opportunities: multi-color printing, the ability to use a separate filament for supporting structures (something water-soluble, for example), and even using the materials with different extrusion temperature since it can be set individually for each hot-end. The team is also working on the technology of using the printheads with different nozzle sizes to get both a higher level of detail and better speed of printing (where the details aren’t needed) at once. Of course, there’s a chance that apart from nozzles there will be probes or laser engravers but it’s only a theoretical possibility at the moment. The whole system will cost more money and the team is planning to offer it as an upgrade option to the base version of a 3D printer.
There’s no release date set on the Original Prusa XL release. Josef doesn’t promise anything since the company has had problems with parts delivery during the pandemic. A rough estimate would be the Q2 or Q3 of 2022. There are pre-orders with refunds available, so one can put an order on the XL even right now.
All of the versions are offered in a partially assembled state. The base single-extruder model is sold at $1,999, while the dual-extruder one costs $2,499. The printhead exchanging system will put the price of the device at $3,499. Another $500 will buy you a pre-assembled device. If the prices change, the company will notify the clients. Currently paying $200 is enough to have a place in the queue.
Apart from the upcoming device by Prusa, the market of the ‘cubic’ 3D printers is full of interesting offerings, especially in the segment of the large-sized machines. The Modix Big-60 would be one of the examples.
