BCN3D Sigma Independent Dual Extruder - First Impressions


Banner of BCN3D Sigma Independent Dual Extruder at Voxel Factory


BCN3D Sigma - Independent Dual Extrusion system (IDEX) 3D printer is now available in Montreal, Canada.


Recently, we added a new printer to our arsenal of FDM and it’s not your regular normal decent functioning printer. At last, we have a fully supported Dual Extrusion, actually it’s Independent Dual Extrusion. Meaning both heads work on their own, one at a time. The printer also features a touch-screen LCD to control your printer (finally).
This is our little review and here’s what we covered:
  • Unboxing
  • Setup & Calibration
  • Slicing
  • First Print
  • Possibilities
  • BCN3D Technologies

Basic Specs
Nozzle: 0.4mm
Layers: 50 to 250 microns.
Build dimensions: 21 x 29.7 x 21 cm (8.3 x 11.4 x 8.3 in)
Build volume: 1 3097.7 cm3 (799 in3)
BCN3D Sigma unboxing at Voxel Factory


The printer comes in a nice big box that has BCN3D Sigma all over it, either the logo of a sketch of the printer. Once you open it, you immediately see two spools of PLA filaments, a tool box, a space for a can of 3DLac (that they cannot ship by air travel) and a two colour printed lizard named Draudi. All of which is placed in cut out cardboard, not the sexiest design but it’s nice.

Fear not, we will add the can of 3DLac for all printers bought in Canada.
BCN3D Sigma unboxing at Voxel Factory
In the tool box you have all you need to operate the Sigma: spool holders, Allen keys, screwdriver, cutters, 8G micro SD card with an adapter and jointing knife to peel off the print. Underneath it all, you find the glass-bed with magnets nicely wrapped in cushiony paper. Also, you have a pocket where the manual is slid in.
BCN3D Sigma unboxing at Voxel Factory
After taking out the whole cardboard cover and the cushions, you can unravel the wonder making Sigma printer. Once you get it out of the box and start marveling at the design, you notice Sigma is looking at you with its extruder fan eyes begging you to start printing.

Just look at it.
BCN3D Sigma with glasses at Voxel Factory

Setup and Calibration

Setting up the printer is easy peasy. Plug in the Bowden tubes, clip them with the wiring and plug in the machine. After that, you take the heat bed and place the magnets over the holes, that’s it (you really can’t go wrong here). Then you follow the “insert filament” wizard which describes every single step clearly you need to make. Obviously you do it twice, because you got two extruders.
BCN3D Sigma calibration at Voxel Factory
Of course, before you start creating two colours pieces, you have to calibrate the machine. Sometimes this is a hassle, but fortunately BCN3D have genius calibration wizard. First the end-stops on each head clicks against the glass a few times in different spots, then the LCD screen will show you how much you should adjust each screw under the heat-bed. It will literally show you to turn the left screw by half a turn (or whatever the amount).
BCN3D Sigma calibration at Voxel Factory
After that, you do the classic slide-in-the-paper to adjust the space between the nozzle and the glass plate, except this time you adjust the height of the extruder on the LCD screen via “up” “down” buttons. You got to make sure that when you push the paper it bends, but when you pull it slides out. Repeat the process for the second extruder.

Finally, each extruder will start printing a rectangle with lines inside it and each line is printed on a different height. Why? Because now you will select the cleanest line to calibrate the head. To do that, you take the “transparent” line as a reference, then count 2 to the right, that line should be your cleanest line. You select that line on your LCD screen and the head will calibrate itself to that option.

Repeat these steps for the second extruder.
BCN3D Sigma calibration at Voxel Factory
Are we done yet? Almost

Now each extruder will print half a box each with lines inside it. You may notice that some lines are not aligned with the other half. Guess what? You will have to select the perfectly aligned combination to calibrate the printer. You do this step twice, one vertical box at the back of the glass and one horizontal box at the front.
BCN3D Sigma calibration at Voxel Factory
If you’re a visual person or if our explication is a bit confusing to you or if you encounter any problem, you can also check out their simple videos and follow (honestly, that’s what we did).


Now you may be wondering how do you slice the print for a dual extruder?

Now, I got to admit that it’s hard to be more impressed at that point, but the slicing just blew our minds. Not only does BCN3D have their compatibility with Simplify3D, but they also made their own version of Cura that is fully compatible with the Sigma. Not only that, but the set up couldn’t be any simpler. They even have preloaded profiles for the filament the printer supports.

Then it’s pretty straightforward. Import the STLs, right click on the object, “dual extrusion merge” and voilà, save the Gcode.

BCN3D Sigma slicing Draudi at Voxel Factory
BCN3D Sigma slicing Draudi at Voxel Factory

First Print Test

Take the glass-bed, spray some 3DLac on it, place the glass-bed on the magnets holders, insert SD card, select the model, press “print”, open beer, enjoy.
BCN3D Sigma first print at Voxel Factory
One aspect that is well thought of is the filament recipient boxes on each side. They’re nice because they keep your printer clean when the idle head extrudes while waiting and they have a piece of rubber that serves to clean off the filament from the nozzle. Just make sure to pick out the discarded filaments after the print.

Also, while printing in dual extrusion, the printer creates a separate little printing box that serves as a pre-print for each layer as well for colour switch. That makes sure that your colour switch actually prints the whole layer.

Our first print was the Draudi lizard, no problem encountered.
BCN3D Sigma printing Draudi two colours lizard at Voxel Factory


Since you can print with two filaments, you can choose if you want a colourful print or a multi material print or even a support print. Support in the sense of one filament is the object you want to keep and the other is the support that you will dissolve after the print.
BCN3D Sigma support printing at Voxel Factory
You can also print with two different materials, like let’s say one flexible and one sturdier. That would allow you to print your own shoes and high-heels. For yourself or for your wife, just an idea like that.

(I’ll just calmly drop this link)
BCN3D Sigma two colour lizard Draudi at Voxel Factory

BCN3D Technologies

So who are the geniuses behind that wonder?

BCN3D Technologies is a Fundació CIM project created by the Poly-technical University of Catalunya, Spain. Its goal is to bring top-notch quality 3D printers to the public’s homes while keeping an Open Source working method.

With all that greatness packed into one box, no wonder that the Sigma has been voted the top printer for three months, and counting, on 3D hubs. (
BCN3D Sigma Independent Dual Extrusion system (IDEX) at Voxel Factory

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