3Drag is now printing with Chocolate!

By on October 21, 2014
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The first 3D printer that creates three-dimensional chocolate objects Click To Tweet

Maitre Chocolatier is born or made? Well, when it comes to creating original chocolate mixes you will probably be born, but if you want to succeed in the art of pastry, then everyone can be made: you just need to have the right tools and equipment. One of these is our 3Drag printer, that modified with a real pastry bag for precision work or a heated syringe is suitable for plotting lettering and lines using any type of chocolate: milk, white or dark. All this, with the advantage to design the object or the pastry directly in computer graphic.

The 3Drag is a FDM 3D printer, but its mechanisms are liable to print not only with plastic, but also with any other material provided: it is sufficient that its melting point is at relatively low temperatures.
Replacing the print head with something able to inject into an extruder a moldable food, such as cream, chocolate, jellies, but also soft batters, allows to produce sweet and savory products with decorations and shapes also particularly challenging.

Hence, the idea of using chocolate, which is easily moldable and allows you not only to create objects quite “tough” and funny, but also to decorate cakes with shapes and letterings without causing any stress that could deform the mechanics of 3Drag or make them loose. More difficult would it be to depose materials such as dough made of flour or something.



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Working with Chocolate


To use chocolate for decoration, for instance to sprinkle it on a cake or to make chocolates of various shapes, you need to “melt” it and sometimes to “temper” it. “Melting” means obviously to melt the chocolate, make it malleable, while “tempering” chocolate is a more complex operation and involves a thermometer (preferably digital).
Our 3Drag is designed only to melt chocolate, keeping it at a high enough temperature to melt chocolate but without altering its physical structure.

To have the 3Drag printing chocolate objects we assembled a special extruder (to replace that used for extruding plastic materials) starting by a very common 60 ml syringe. A NEMA17 stepper motor drives its piston and a heater to maintain the chocolate contained in the syringe at a temperature of about 32 ÷ 33 ° C wraps the cylinder.

Chocolate must be melted before being extruded through the syringe needle (having an internal diameter of 0.9 mm); its fusion is achieved by activating the heater in which is inserted the syringe, without exceeding the threshold of 33 ° C (so keeping the chocolate “tempering”). For this reason, the control board constantly detects the temperature of the heater thanks to a NTC 100 kohm thermistor installed directly on the body of the aluminum cylindrical heater.
The loss of “tempering” of the chocolate would make impossible to print objects that develop in height, and then the chocolate itself would not be able to solidify at room temperature (24 ÷ 27 ° C).
Aside from maintaining the temperature below that threshold, you have to deal with the chocolate cooling time, which affects the printing speed. In fact, depositing a layer of melted chocolate (it’s hot) on a lower layer not yet solidified can deform the object; so the application of a layer must be carried out only when the underlying one is cool enough to bear both the weight of the chocolate above and the heat supplied by the melted chocolate deposed.
Let us say that if you are working with a relatively small chocolate amount, like the quantity that can come out of a needle with an internal diameter of 0.9 mm as that used in our tests, you can go fast. In any case, you have to choose, basing on your experience, the appropriate printing speed testing adequately the functions and settings of the printing software (Repetier-Host, Heal, etc).
To speed up the chocolate cooling process we decided to use Peltier cells, to realize a compact airflow cooling system blowing directly to the zone where the melted chocolate is deposited; this solution has proven to be the best.


How to extrude the chocolate

The system that we use to depose the melted chocolate consists on heating the body of the syringe and the needle even more, through a special electric heater resistance. The needle is inserted into a perforated cylinder that let it pass through and hosts the coupling. The whole system is able to bring chocolate to the required temperature and keeps it stable. In this way, the chocolate close to the needle tip melts and can leak. For this to happen, you have to push the piston of the syringe by applying a regular and continuous pressure: here comes the activation of the feeder, which consists of an endless screw that pushes down the piston itself.

If all the chocolate in the syringe is “pre-softened”, that improves the whole process: this is the reason why the entire syringe body is inserted into an aluminum cylinder whose dual purpose is to support the syringe and transfer the heat from the heater (the one that heats the needle).
Since aluminum is a good heat conductor it transmits very well the heat to the syringe but on the same time its outer surface tends to waste heat; For this reason, we decided to wrap the outside of the cylinder with a heater in Kapton film.
The syringe may be loaded in two ways: by pouring inside it the chocolate already melted at low temperature before inserting the syringe into the cylinder, or by putting inside the syringe chocolate flakes and melt them thanks to the syringe heater.


Modify the 3Drag: print head for chocolate


To print with chocolate it is necessary to make some modifications to the printer, but just limited to the replacement of the original print head (and its feeder) with an extruder ad hoc.

Therefore, you have to remove the original head from the horizontal rail of the print head holder and fit the new head, which consists of a syringe and its special housing that has the dual responsibility to support and heat, as well as the endless screw mechanism that presses on the piston to control the injection of the melted chocolate. The completely new head is supported by a guide, which is then anchored to the horizontal profile of the 3Drag.


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The chocolate extruder is composed of the following elements:

  • 60 ml syringe for medical use with central needle attack “Luer Lock” which is applied to a standard needle of 1.2 mm diameter (0.9 mm internal), suitably shortened to 33.5 mm;
  • Cylindrical aluminum body with outer diameter of 35mm and inner of 31,6 mm, suitably drilled on which is wound a “flat” heating cartridge with a supply voltage of 5 V DC;
  • Cylindrical aluminum block (on which is fitted a cylindrical heater cartridge 15V / 33W) properly drilled;
  • Needle sleeve (made from a rod of aluminum) that “keeps warm” the needle of the syringe during printing;
  • The extruder system so assembled, attaches to the printer structure and is completed by:
  • Aluminum rail IGUS (cod. NS-01-27) from 27x300mm which also represents the backbone of the whole extrusion unit;
  • Skid IGUS (series 27 cod. NW-02-27) which is anchored to the syringe piston through a bracket made of Delrin;
  • Aluminum plate, 4 mm thick, for the fixing the gear wheel;
  • Aluminum angle bracket for mounting the extruder to the arm of the 3Drag printer;
  • M8x190mm threaded rod to drive the syringe piston;
  • 2 ball bearings 8x22x7 mm with dust protection;
  • Supports for the fixing of the heater, the syringe and the motor, gear wheel with 43 teeth (Ø66,2mm) and 10 teeth pinion (Ø 17,6mm) made of Delrin;
  • A NEMA17 2.5A stepper motor, the same used for the extruder for plastic, drives the feeder that pushes on the piston of the syringe. The heating element to be inserted in the cylindrical aluminum block is 15V / 33W, while to coat and heat the cylinder you have to apply the “Flat” heating element coupled with a NTC axial 100 KOhm thermistor.


Assembling the extruder



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Once in possession of all the necessary elements you can proceed to the assembly of the various elements of the extruder, as follows:

  1. Insert the cylindrical block in the holed end of the aluminum cylinder;
  2. Insert the cartridge heater in the cylindrical block after it has been sprinkled with thermal paste, then lock it with a M3 grub screw;
  3. Slide the skid into the aluminum rail and then attach to it, with M4 screws: the support for syringe, that for the heater and finally the one for the motor;
  4. Insert the two bearings in their housings;
  5. Mount the Delrin bracket on the skid using two M4 screws. On the bracket you shall fix the M8 threaded rod with a self-locking nut on one side and a classic nut with lock washer on the other;
  6. Insert on the threaded rod (engine support side) a 8×16 washer, then the Delrin gear wheel and M8 nut; put the Delrin pinion on the motor shaft, then attach the motor to its support after checking the correct coupling between the gears;
  7. Fix the pinion with grub screw;
  8. Then assemble on the motor support four spacers by 20 mm;
  9. Fix the aluminum plate to the spacers using four nuts;
  10. Fix the aluminum angle bracket to the guide by using two M4 screws with countersunk head;
  11. Now you need to take up the aluminum cylinder port-syringe and apply the NTC thermistor on its outer surface, and then secure it with Kapton tape;
  12. Wind up on the cylinder also the “flat” heating element fixing it with Kapton narrow tape;
  13. Fix the full cylinder to its support using two M4 screws and then insert the needle in the appropriate “aluminum sleeve”; then insert the syringe into the cylinder until you get the position; by doing this, make sure that the syringe is free to swing front to about 45 °.




You have succeeded in assembling the new print head that allows printing with chocolate; now you have to mount it on 3Drag. To do this, you must remove the standard installed extruder for plastic, and then proceed as follows:

  1. Insert two square nuts M5 in the upper slot of the printer arm, and then attach it to the chocolate extruder using two M5 screws
  2. Connect in series the two cartridge heaters and make the electrical connections for the heating element thus obtained and the extruder NTC


The mechanical modifications to the printer end here. In order to use the printer as 3Drag for chocolate you must also update the firmware of the electronic board.

The firmware “Marlin V1 (LCD ON, Choco ON)” can be downloaded directly from here.
Obviously, the firmware can be changed to your preference every time you wish, depending on the extruder mounted on the printer.


Changing the firmware

To operate with chocolate it is necessary allowing the heater to reach much lower temperature than that usually used with plastics. We must remember that the Marlin firmware comes for the control of FDM 3D printers using plastic filament and includes a whole series of protections including that one which prevents to extrude the material below 170 ° C. Having to melt the chocolate at a temperature of about 33 ° C we have to change the statement:




This change moves the protection threshold from 170 ° C to 10 ° C.


Another necessary firmware change concerns the steps/mm of the extruder motor, because of its different mechanic conformation. The instruction to modify is:

#define DEFAULT_AXIS_STEPS_PER_UNIT   {64.25, 64.25, 2560, 600}

The last parameter (600) indicates the rotation speed of the motor.

To obtain a right extrusion speed, allowing thus fluid extrusion of chocolate, this value must be reduced by 10 times so the correct instruction will become:

#define DEFAULT_AXIS_STEPS_PER_UNIT   {64.25, 64.25, 2560, 60}
Another change relates to the PID that controls the temperature: to prevent excessive fluctuations, we modify the parameter P:

#define DEFAULT_Kp 22.2


#define DEFAULT_Kp 32.2

This value has been calculated empirically but gave great results on real printing.

The modified firmware is available for download. You can use the Arduino IDE to program the 3Drag Controller (like Arduino Mega2560).
To disable the hot bed you have to insert a 120Kohm resistor on THERM2.



Precautions for printing

As already mentioned at the beginning of this post, we must remember that the cooling time of chocolate layers is much longer than that used when printing with plastic. We therefore recommend a printing speed of maximum 20 mm / sec to have individual layers of chocolate cooling down properly.
In the Slicer parameters, we must set the nozzle diameter to 0.9 mm (you can also set it to 0.8mm to “cheat” the slicer and then make higher definition prints), the layer height to 0.7mm and the extruder temperature not exceeding 35 ° C.
As for the 3D prints with plastic, it will take several tries to get the best results.

The configuration parameters also depend on the shape of the object, the type and quality of the chocolate used and the ambient temperature environment in which the printer operates.
Therefore, the determination of the parameters is the result of personal experience gradually gained into this field.

Configuration files

Download the configuration file to setting Repetier Host

From the Store

You can buy all the extruder component from our Store



About Boris Landoni

Boris Landoni is the technical manager of Open-Electronics.org. Skilled in the GSM field, embraces the Open Source philosophy and its projects are available to the community.


  1. Pingback: Uma impressora 3D Modificada para imprimir chocolate | Portal da impressão 3d

  2. bonooobong

    October 29, 2014 at 11:45 AM

    is it the same 3d printer listed here? http://goo.gl/EHTmIB
    because it’s called K8200, I want to buy one but because of the upgrade opportunities for chocolate/pasta extruder or mounting a Dremel on it. Any tips?

    • BorisLandoni

      November 4, 2014 at 4:31 PM

      We have developed the 3Drag. In collaboration with Velleman we started mass production and they have called it K8200

    • fred

      March 7, 2015 at 4:19 AM

      Tips for dremel?

      • BorisLandoni

        March 9, 2015 at 10:18 PM

        Yes, of course. check the top menu

  3. Juliusk

    November 25, 2014 at 4:51 PM

    Hi, I have sent a request regarding the 3Drag Printer and Choco Extruder but it seems like there is no reply.

    Any advise?

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  7. disqus_z6QwAdKvtH

    December 19, 2014 at 10:55 AM

    Hi, I have just come across a link with very good and detailed instructions on how to build the Chocolate Extruder in Italian…….


    Hope that this will be of help to you all…..

    • Florian Horsch

      January 2, 2015 at 5:21 PM

      This helped a lot! @Open-Electronics: I would recommend to include this link into the official manual. The photos are much more detailed. Thanks :-)

      Via Google translation is easy to get a native translation.

    • chocchef

      March 11, 2015 at 5:26 PM

      Thank you for turning terrible instructions into really clear instructions! Your’s should be the official ones

      • disqus_z6QwAdKvtH

        March 11, 2015 at 5:40 PM

        Hi chocchef……

        Many thanks for your feedback…..
        Just to make clear though, I found the link online……

        It was not me that prepared the instructions!

        All our thanks should go to the original authors of the article…….

    • chocchef

      April 1, 2015 at 10:16 AM

      The italian instructions were translated:

      Thanks guys

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  9. Florian Horsch

    January 2, 2015 at 5:23 PM

    Can anybody give me a hint how to connect the chocolate extruder to a 3d printer with 24 V power supply?

    For the heater cartridge I have 12, 15 or 24 V available. For the flat kapton heater there’s only the 5V offered by OE.org. Is it possible to connect 15 V + 5 V in series or is it better to go with 24 V + 5 V in series?


    • BorisLandoni

      January 9, 2015 at 6:03 PM

      Hi, the flat kapton heater is an optional, you can use onle the 24V cartridge

  10. Luis Afonso Mota

    February 18, 2015 at 7:16 PM

    Hello, I have assembled the extruder but in the end when im trying it out i realized that it retracts instead of extruding… what can I do?

    • BorisLandoni

      February 19, 2015 at 5:57 PM

      Revert the motor connection

      • Luis Afonso Mota

        February 19, 2015 at 6:41 PM

        Is there a way to change it via software or firmware? I am using the same motor so i didnt want to switch cables everytime i change extruder

        • BorisLandoni

          February 20, 2015 at 12:02 PM

          Yes of course, you can change from firmware (marlin)

  11. Chocolatmagic

    February 19, 2015 at 9:44 AM

    very interesting article. We are manufacturers of chocolate cups for champagne or to make desserts. http://www.chocolatmagic.com

  12. Pingback: Print With Chocolate in 3D | DIYGadgets

  13. Jason

    May 14, 2015 at 5:53 PM

    I have a problem,I don`t know how to set the proper speed for the motor.I tried several speed ,and I found if the speed was too high may cause the jam of gear and stop the motor.if the speed was too low the volume of the chocolate was not enough to print.Can someone give me some tips?

    • BorisLandoni

      May 27, 2015 at 10:44 PM

      Normaly the extrude for plastic works with 600 step/mm, for the chocolate set 60 step/mm

      • Jason

        May 28, 2015 at 4:06 AM

        Thanks,I will have a try~

  14. Izhrin

    July 5, 2015 at 11:12 AM

    hye, can ur chocolate extruder being assembled in standard reprap prusa i3 3d printer?. What are the additional parts or modifications that i need to do for ur chocolate extruder kit in ur store to perfectly work with my standard prusa i3?

    • BorisLandoni

      July 18, 2015 at 4:32 PM

      Hi, I’m sorry, but this extruder is for 3Drag

  15. Eduardo Pereira Martini

    August 12, 2015 at 8:53 PM

    is this printer capable of retractions?
    in all the axis?

  16. Veo

    September 22, 2015 at 8:17 PM

    can you put up a better version of the 2d plans for the extruder. Its too blurry and hard to read.

  17. Caciano Genz

    January 15, 2016 at 5:34 PM

    This product is shipping to Brazil?

  18. maha

    February 29, 2016 at 7:49 PM

    Hello guys

    I just got syringe to print choco from 3 drag , my motor was working well with the filament but once I changed it to print choco it stops working

    I have followed the structures step by step but nothing changed
    am not sure I may have a problem in updating the electronic board or in the firmware for marlin choco ??!
    I would appreciate if someone can assist


    • BorisLandoni

      March 3, 2016 at 9:54 AM

      Have you changed the firmware?
      You can download the right firmware here:

      • maha

        March 3, 2016 at 11:10 AM

        Thanks BorisLandoni for quick replay , I would really appreciate if you could tell me what shall I do exactly after download the firmware


        • BorisLandoni

          March 14, 2016 at 4:47 PM

          You have to use Arduino IDE to upload the firmware (sketch) inside the main board.
          In IDE select the Atmega2560

      • maha

        March 8, 2016 at 10:21 PM

        Dear BorisLandoni

        Do you recommend me any website that explain in more detailed ?
        I mentioned to you before that I followed every thing step by step .
        I updated the firmware of the Microcontroller (ATmega 2560) from Arduino website + downloaded the Marlinchoco ,I made the changes of the ( Configuration.h) file
        But still have stepper motor not working , its written in the 3d Repiter- host that ( cold extruded prevent ) >>??
        is there anything I can do to overcome that ?

  19. Massimiliano

    March 2, 2016 at 5:11 PM

    Ho comprato il kit da piu’ di 3 mesi e ancora non sono riuscito a fare un oggetto di cioccolato che uno. Ma non ci sarà il trucco? Poi, alle email e ai tweet non rispondete, cosa devo fare ancora per la vostra attenzione?

  20. Massimiliano

    March 2, 2016 at 5:21 PM

    Ho comprato il kit da piu’ di 3 mesi e ancora non sono riuscito a fare un oggetto di cioccolato che uno. Ma non ci sarà il trucco? Ho seguito tutte le vostre istruzioni le modifiche del firmware e le configurazioni di slic3d ma non c’è niente da fare a meta si blocca e non esce piu il cioccolato

    • BorisLandoni

      March 3, 2016 at 9:52 AM

      What’s your problem?
      (please write in english here)

      • Massimiliano

        March 3, 2016 at 10:08 AM

        I also sent to you an email last friday. However i tried many many times to print chocolate things but everytime there are various problems, like stop to extrude chocolate when the printing is reach 3 or 4 cm of height. It seems there is no control of chocolate flow, also i found solid chocolate on the plastic funnel of the needle so make me think that there is also no control of heating, must put thermal paste on needle because there is space between needle and aluminium socket? must use complete metal needle? Which kind of chocolate need? can you tell me where to buy the same chocolate? Thanks

        • BorisLandoni

          March 3, 2016 at 10:32 AM

          Chocolate inside the syringe should already be loose.

          The extruder heater only serves to keep loose, not to dissolve it.

          Be sure to put the aluminum jacket around the needle. The needle should be ours and must extend from aluminum for a millimeter.

          We use normal drops of dark chocolate (from Iper….)

          • Massimiliano

            March 3, 2016 at 1:06 PM

            Sorry but i follow every steps as you describe on this page:
            But everytime i obtain this result (i progressive reduce the speed as the chocolate flow decreases to maintain the continuity how much i can and i must check every minutes) :

          • BorisLandoni

            March 14, 2016 at 4:49 PM

            Are you using the cooling system? If you need to print high 3D object I suggest you tu use a cooling system

          • Massimiliano

            March 14, 2016 at 5:46 PM

            Yes of course. I bought and built the suggested cooling system with peltier cells. I think you never read the email I sent to you 18 days ago. In anycase i have a theory that explains why the chocolate flow decrease. Because the chocolate flow has no control (when the chocolate is melted then flows down by the gravity force, maybe it needs a valve synchronised with the step motor) it creates an empty space like a inverted cone just between the rubber piston and the hole at the bottom of syringe. I notes this many times after I toke out the syringe for cleaning.

          • BorisLandoni

            March 15, 2016 at 5:34 PM

            You can reduce the flow rate. If you are try to close the upper layers yu have to create an infill (as a normal plastic 3D printer).

          • Massimiliano

            March 16, 2016 at 3:56 PM

            i’ve done another attemp, following your advices and i completed the model but there is still the problem i mentioned. If you take a look at the photo i attached, you can see from the “arms” layers i encountered many problems to try to complete the printing, as i reduce the speed, as i stop and play the printer and extrude the chocolate in other zone of bed until the flow become more fast and then resume, but the flow tend is the same, in other words, i need to reduce the speed from initial 75% to 20% at the last layers. https://uploads.disquscdn.com/images/6f5e1bfd0e43ad6742af42224e0df9c3538dee7a415dd7d2b9b61ef97f52163f.jpg

  21. Maria Granlöf

    March 15, 2016 at 9:25 PM

    Do you have a stl file of the cup printed in the example above?

    • BorisLandoni

      May 8, 2016 at 9:47 AM

      • Maria Granlöf

        May 25, 2016 at 12:03 PM

        Hi Boris, thanks for this. However, I guess what I’m looking for is an stl that contains the printing instructions. Do you have some recommended settings for the slicr that I can use? I don’t manage to get this cup to print correctly.

  22. Maria Granlöf

    August 16, 2016 at 2:25 PM

    Hi, has anyone had problems with the connection to the printer being dropped all of the sudden? The board starts blinking red and the computer cannot find the USB port any more. Anyone that might know what causes this?

  23. Salim Benyoucef

    November 30, 2016 at 10:28 AM

    We got many problem with this printer and we don’t know how to resolve those problems, I tried sent many email through this website (CONTACTS) but unfortunately till now no answer!!!!.
    I’m wondering how to sell this machine without good custom services ?!!

  24. Salim Benyoucef

    December 6, 2016 at 7:27 AM

    Please don’t buy this product, I would advise you don’t buy it.
    Many problem many bugs.Further, no service customer!!!!
    The board was damaged I bought new one, I got documentations in Italian I sent email written in the manual all are wrong!!!!

    • BorisLandoni

      December 6, 2016 at 9:06 AM

      You can find all info in this site. We don’t receive any mail. We have also a RMA service.

      • Salim Benyoucef

        December 6, 2016 at 2:07 PM

        In this same page where you replied there is my first post and in the same time I sent you many messages through CONTACT.
        And I bought new board due that the first was damaged and I tried to upload the choco firmware can you help me ?!!
        Can you give me any email that of custom services?!!

  25. Math

    December 13, 2016 at 1:50 PM

    Hi, I test your cooling system, but it seems to
    be not powerful enough. It is possible to get the stl files of the cooling
    system in blue (with the horn) we see in the video?

  26. Math

    December 13, 2016 at 4:16 PM

    Hi, i just tested your printing machine. The cooling system seems to be not
    powerful enough.

    It is possible to get the stl files of the system see in the video (the blue horn?)
    I think it will be better than the one with the ring.


  27. Hesam Mahdinejad

    September 13, 2017 at 1:12 PM

    Could you ship the product to UAE?
    How long does it take the printer make for example a chocolate cup?

  28. Manuel Garcia Russo

    October 1, 2017 at 2:04 AM

    Hello I needed to know what is the velocity of printing and and the lifetime of the printer thank you

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