Qubit3D is completely hand-assembled in Italy and uses Openbuild hardware-based mechanics with an open source model. The structure is in aluminum and the linear movement is assured by delrin or polycarbonate wheels, made individually on a numerical control tool. The mechanical model is of Cartesian type, with independent printing plate on Y axis and print-head on X and Z axis. The axes are moved by GT2 belts with Nema17 stepper motors. The extruder is a direct type, with a 1: 1 ratio, it mounts a hotend which allows to extrude, in addition to plastics like PLA and ABS, flexible filaments and filaments that melt at higher temperatures (up to 260°C). The filament is guided by a Teflon sheath that prevents clogs during the printing process. Qubit3D is under a Creative Commons Lincense (CC BY-NC-ND 3.0)
Design and Characteristics
Its strenghts are: ease assembly and maintenance, starting from basic components it can be assembled in 3 hours and it can be replaced every part in few minutes. The essential structure is therefore solid and movements are driven by linear actuators of 80 mm.
Its movements can reach 300 mm/second and it works best from 60 to 80 mm/s with PLA/PET, wood and bronze.
The extruder (0.40 mm hole with filament of 1.75) is totally "naked" and allows not only to check eventual problems but also to make "corrections" during printing.
The printing plate (400x300 mm) does not require regulation, the firmware permits the levelling of the bed.
The first prototypes were subject to severe trials, printing some objects of various size and duration (up to 300 hours, continously). Among the most interesting stress tests there is “Robotica” at life-size.
|Printing volume||300 x 400 x 250 mm|
|Printing speed||up to 120 mm/s|
|Max print-head temperature||260°C|
|Nozzle diameter||0.4 mm|
|Type of extruder||Direct|
|Motors||Nema17 (1.8°) stepper motors|
|Controllers||DRV8825 1/32 step|
|Display||Full graphic 128x64 pixels|
- 1. Filament material: 1.75mm
- 2. Teflon sheath: leads and guides the filament to the inside of the extruder.
- 3. Drag mechanism: pulls the filament into the print head during the extrusion process.
- 4. Filament release mechanism: when pressed, it unlocks the drive mechanism and allows the wire to slide freely. Required during filament insertion and removal.
- 5. Cooling fan: cools the mechanical component of the extruder and the object printed.
- 6. Print-head: hot component of the extruder, dedicated to the melting of the filament and its extrusion in a filament with a smaller diameter (0.4mm).
- 7. Display: screen to manage printer functions.
- 8. Reset button: sends the reset command to the electronic board: the FDM module interrupts any activity.
- 9. Selector: by rotating and pressing the key it is possible to select the display items.
- 10. Print plate: surface on which the object is created.
- MKS mini 1.2
Chinese production card (Makerbase), clone of the Arduino Mega 2560 System and RAMPS engine module 1.4. The motor drivers (4 in all for the three axes and for the extruder) are integrated in the card. Allows one engine control at 1/16 and 1/32 pitch.
- MKS mini 2.0
Chinese production card (Makerbase), clone of the Arduino Mega 2560 System and RAMPS 1.4 engine module, evolution of version 1.2. The motor drivers (4 in all for the three axes and for the extruder) are integrated in the card. It allows a 1/16 motor control (default setting) up to 1/128 pitch. It has in addition to the previous version the control for the heated plate and more efficient motor drivers.
- Arduino Mega2560 + RAMPS 1.4
Arduino Mega 2560 and RAMPS controller 1.4. "Original" version compared to the MKS solution. How it works the three systems shown are identical. The difference of the RAMPS module is the encumbrance, these are two cards that interface one above the other and an additional motor controller (for a secondary extruder). It is also possible to replace the motor drivers by selecting between different 1/16 or 1/32 pitch models, in case one or more than one is damaged. This feature makes repair operations easier by avoiding the complete replacement of the board.
Various printer designs have been designed and implemented. One of these solves the problem of encumbrance of cables by using fairlead chains, automatic end-of-wire sensors or plate leveling, with a "delayed" extruder (3: 1 ratio). Electronics have also been revised, using Arduino Mega 2560 and Ramps 1.4, writing a special firmware. An electrical system has been added to compensate and eliminate the static electricity that can flow to the motherboard from every part of the metal structure, damaging the circuits. The system includes a series of mass wires organized in a "star" center. The plate self-leveling function is provided. The system takes 81 points, whose relative height on the plate is automatically adjusted and interpolates a plane that corrects the irregularities of the physical plate, through the use of a Hall effect probe.
The following is a list of the main advantages:
- Easy to assemble
- Fast maintenance
- Easy alignment during assembly thanks to the "cantilever" design
- Large printing area
- Cheap (less than € 500)
Thanks to Maurizio Mambrin, Alessandro Chiolerio, Vincenzo Guarnieri, Paolo Pandolfi, Jessica Barolo, Simone Paschetto, Marco Cotto, Paola Martino, Alessandra Rosa, Riccardo Dardano, Marcello Prisco, Mattia Palombella, Sonia Matera, Elisabetta Rosolen, Daniele Passamonte, Raffaele Spina, Pietro Giuliano, Arianna Vergani, Sonia Vairo
- Politronica's website Politronica Inkjet Printing
- Qubit3D's website 
- Freebot (http://www.thingiverse.com/thing:570718)
- Printbot (http://printrbot.com/shop/assembled-s...)
- Ormerod 2 (https://reprappro.com/shop/reprap-kit...)
- Funbot (http://www.thingiverse.com/thing:560343)
- Bukito (https://www.kickstarter.com/projects/...)