Open Source Large Scale 3D Printer


We dream in a future of freedom, where open source hardware and Fab Labs enable people to fully understand how to make things they need, and where decentralized local production is customized to impact the surrounding community. Believing that empowering the user with knowledge about how to make machines, BigFDM wants to give to the world a powerful open source tool, to 3D print any large scale object you may need. And, together with LaserDuo, this is one of the first steps in developing other machines sharing the same philosophy.


BigFDM is an open source large scale 3D printer.

Taking advantage of what we have learned in Fab Academy, BigFDM has been developed using standard Fab Lab equipment and techniques. BigFDM was in fact built in Fab Lab UAE by Daniele Ingrassia with the help of Hashim Al Sakkaf. Reversing the consumer process, where knowledge and building of machines stays inside a black box managed by companies, BigFDM brings the advantages of an open source development:

BigFDM allows the printing of large scale objects, some examples can be orthotics and prosthesis, art installations, furniture, replacement parts, industrial design prototypes, molds for casting of full scale parts. Using Fused Deposition Modeling (or FDM), it can use standard 2.85mm 3D printer filament, and as well common extruders nozzles.

BigFDM specifications:

Machine design

BigFDM has been designed considering to keep fixed from the beginning few constraints, which then influenced the rest of the subsequent design choices:

These have been tought in order to bring the following benefits:

X and Y stages

The X and Y stages integrates all their components inside a squared plane frame of T-Slots profiles. Hiwin 15mm linear guides and 10mm GT2 belts, together with custom CNC milled POM parts have been used. Implementing a sort of stages interoperability, the stages frame can be completely detached from the machine, and virtually, plugged into a different machine having similar frame shape (eg a laser cutter). Similar interoperability has also been recursively kept for the Y axis, which can be modified/removed without changing the X axis.

Z axis

The Z axis uses a single NEMA 24 to move 4 lead screws guided by 4 linear rods and bearings. A 4.7m closed loop HTD M3 belt is used to transmit the movement with a 2 to 1 pulley ratio. The lead screws are supported by ball bearing both at the top and the bottom, where also pulleys are attached. The corner structural parts are made with CNC milled 20mm acrylic, while the rods and bearing supports use CNC milled POM. Because of layer by layer downwards needed movements, the bed will never move fast, with the maximum speed used more for manual movements. The main frame is used as support structure for all the Z axis parts.


Made out of a 6mm aluminum plate cut with the CNC, the printing bed is suspended onto a lower frame structure by using 4 x 8mm DIN 912 bolts. The lower bed frame in turn is attached to the Z axis lead screws and linear rods. The lower frame is kept parallel to the upper stages by mechanically aligning it during the assembly, while the printing bed flatness can be finely tuned by screwing/unscrewing the 4 bolts. The design of the printing bed takes into account its thermal expansion, leaving a tolerance of expansion that exceeds the calculated one from the aluminum.


The housing has been developed to keep the internal temperature stable, and to allow the bed to quickly warmup. Because the machine parts have been constrained to be inside, the housing is attached directly to the main frame, and no additional parts are needed. The corners are made by 4mm aluminum composite (also called as dibond), while the windows are 6mm acryllic. Both materials have been CNC milled and the design is made in a way to fit two full sheets (about 2400x1250mm) of acrylic and one of aluminum composite. The tablet enclousure is made with the same materials, and allows to quickly remove it from the top.


The electronics of BigFDM consists of a set of fabbable electronics, derived from the original satshakit board and satstep stepper drivers, plus some additional boards. Following the used boards and their role in BigFDM.


Based on the ATMega2560, this board provides the necessary microcontroller hardware for the Marlin manage its logic functionalities. Furthermore integrates an USB-to-Serial converter and USB port. Developed as general purpose board, not all the pins will be used. In the future this board will be a custom made solution for BigFDM. Link to the original repo.


Proved to have a robust design by being used in LaserDuo for more than a year, the satstep6600 is the stepper driver used to move the NEMA 23/24 used in BigFDM. Based on the Toshiba TB6600HG it can give up to 4.5A per coil to a single motor, whereas the NEMA 24 used will take a maximum of 4A. Link to the original repo.

Mosftet Board

Developed as an add-in to the satshakit-mega for BigFDM, the mosfet board integrates 4 mosfets to drive the nozzle heaters and the solid stae relay for the bed heaters, plus two slots for Pololu A4988 or similar stepper drivers. The A4988 are used to drive the two nozzle stepper motors.

Sensor Board

The sensor board integrates simple design with filtering capacitors and pull-up resistor. To this board the thermistors from the extruder and one of the thermistor of the bed heaters will be connected, together with the analog pins from the satshakit-mega.

Endstop Board

In a similar way of the Sensor Board, the Endstop Boards has some pull-up resistors and some capacitors to filter the noise coming from the endstops. To this board the endstops and the limits min (x-min, y-min, z-min) from the satshakit-mega will be connected. BigFDM uses normally open endstops.

Summary of the needed boards:

To power all this electronics, and to switch on and off the heaters the following additonal parts are needed:


BigFDM uses Marlin firmware running on the satshakit-mega. The configuration changes have been applied into the configuration.h file, you can find it in the config folder of this repository.

To control the machine and to stream the G-Code, Repetier-Host has been used.

Build your own BigFDM

BigFDM is made by using a mix of fabricated and ready-made parts. The ready-made parts are selected to be as common/standard as possible, to make the sourcing of them easy in many countries. For both the raw materials needed for the fabricated parts, and the ready-made parts, refer to the Bill-of-Material for details: BigFDM BOM

The fabrication of the parts mainly relays on standard Fab Lab equipment. It will be therefore possible to make BigFDM in any of Fab Labs worldwide having it. Below a list of the required tools and machines:

Both fabricated and ready-made parts have been modeled inside the BigFDM Fusion 360 model. Using Fusion is possible to export/prepare the parts for production in the following ways:

For more details about the tools and once you have all the fabricated and ready-made parts parts available, refer to the for step-by-step assembly instructions and tips: BigFDM Building Manual

Big FDM requires different fabbable PCBs to work. Below the download links for the eagle files that you use to fabricate them:

Download here the configuration files (right click save as):

Known issues


BigFDM printing

How to Make BigFDM: Tunisia Workshop at Fab Lab ENIT

BigFDM pictures


Daniele Ingrassia

Project Helper: Hashim Al Sakkaf


Our dream is to have impact by making open source machines digitally available and locally produced anywhere in world. We plan to open a dedicated Fab Lab to foster open machine building and digital fabrication research. Practically several tasks and many expensens have to be sustained to give this dream the chance to have a future. Such as the renting of a proper space, the making/purchasing of proper equipment, the sustainability of our work and lifes. If you share this mindset and BigFDM is useful to you, please help us to make this dream a reality by donating your support:



The development of this machine has been funded by: German Federal Ministry of Education and Research

Funds implemented by: OpenLab Hamburg Helmut-Schmidt-Universität Universität der Bundeswehr Laboratorium Fertigungstechnik Holstenhofweg 85 22043 Hamburg

Thanks: Fablab UAE 176 6 D St - Satwa Dubai - United Arab Emirates

Paul Anand


BigFDM is licensed under the terms of the open source license: Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0).


This documentation will be continuously improved as soon there are updates and/or improvements on the machine.


This hardware/software is provided "as is", and you use the hardware/software at your own risk. Under no circumstances shall any author be liable for direct, indirect, special, incidental, or consequential damages resulting from the use, misuse, or inability to use this hardware/software, even if the authors have been advised of the possibility of such damages.