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BLV mgn Cube

3D Printer

Hi, my name is Ben Levi and This is BLV mgn Cube - an open-source 3D printer project. building your own good and reliable 3D printer is the main purpose of this project. Basically, it's an open front structure CoreXY 3D printer, based on

mgn linear rails for maximum accuracy, efficiency

and high print quality.

blv cubg mgn trans-min.png


This is the calibration step.

In fact, before we will start the calibration process, it is first necessary to make sure that the appropriate firmware is installed on the Duet board. The duet board had the old Reprap 2.x.x version when the Project has been released. In the time it was upgraded to Duet 3 board running the new Reprap firmware v3.x.x . If you are still using the old good Duet 2 Wifi board, Then our dear friend David Husolo has done amazing work creating his BLV cube config GitHub source -  a compatible and well-calibrated config file for both Duet2 Wifi and Duet 3 running Reprap 3.x.x.

In some of the following steps, I will refer you to the excellent Duet guide platform. with the help of the Duet step-by-step guides, you will be able to start calibrating your board and eventually print high-quality prints.

Note: after I will finish the new Step by Step guide for Fysetc Kit, I will share with you my fine-tuned config files.


Before you can use any of the BLV mgn Cube firmware configuration files, you first need to make sure that there is an updated Reprap firmware running on your Duet board. Luckily Duet boards are the most documented boards. therefore, they have specific step-by-step guides for almost anything. I recommend updating your Duet board to the latest Reprap firmware 3.x.x before you will do any calibration process.

First you should download the latest version of the Duet firmware (3.x.x). it can be downloaded from here:

Now that you have the latest firmware files, you can proceed and update your Duet board.

Duet 2 WIFI and Duet 3 share the same updating guide, Just follow the Step-by-step upgrading guide:

After updating the Board you should now copy the basic BLV Config filesinto your sd-card. If your sd-card is new or empty, please follow this guide first and re-constract your Duet sd-card. inside the Project's Zip file there are two sd-content zip files. One is the basic config for Duet 3 and the other suitable only for the old Reprap version 2.x.x. IF you have updated your board to the recommended version 3.x.x then you should use David Husolo Config files, you can find all the needed files in David's Github under the "firmware" folder. again - Thank you David for the amazing work!

If you have the FYSETC kit then you should know that FYSETC uploaded a suitable firmware and it's available here.

Duet has an internal web interface that allows you to gain complete control of your 3D printer. After updating the board, you will surely want to start using it by connecting to Duet web access and start using your printer.

Please follow this guide, it will help you define your network settings and get access to your board:


Some important do's and don'ts to avoid damaging your Hardware:

  • Never disconnect cables from your duet board when it's connected to a power source, unless it is a USB cable.

  • Check all wires and avoid shorting the wires, especially the fan wires, motors and heaters.

  • Do feed your board more then 24 volts.

  • Ground your extrusions frame and your Bed carriage, it will be great if you could ground the motors too.

  • When installing the electronics, be careful not to scratch, shorten or damage them.

  • Do not remove the memory card from the duet board while the printer is running.

  • Take your time while crimping connectors, check the wires using the multimeter!

  • Tripple check "+" and "-" wires to make sure they are plugged in properly and to the right place.

  • When the stepper motors are connected, don't move axis by hand causing the motors to spin quickly.


Although the Provided config files cover almost everything, you may want to make few final changes such as centering your bed, setting the directions of the motors, setting macro buttons, define temperature sets for each filament, and so on.

In order to that, you may need to change the config file. Thankfully, the duet has an excellent guide that covers all of these topics and much more. All the Duet guides can be found here


guides you must follow before moving on to the next step:

Setting up your stepper motors

If you have the FYSETC kit you can skip to the next step, since fysetc kit has a plug & play cables set - labled cables with the correct wires order, suitable with the Fysetc config files.

If you purchased the steppers from the BOM or has the Blurolls kit, then your motors will probably will not turn in the right direction (unless you are really lucky). In order to setup the stepper motors, you should follow the following steps:

motors steppers note-min.png
  1. Identify the coils/phases wires
    your stepper has 4 wires - 2 for each one of the coils/phase
    and you need to identify the pairs. Click here for a quick guide
    for identifying the wires, you can watch this video


  2. Connect your steppers
    Please use the original Duet steppers wiring while connecting the steppers. you can find it in the right button corner of the Wiring Diagram v3.2 (under the text headline: "Duet original steppers wiring")


  3. Test and configure
    the steppers according to Duet documentation
    I uploaded a video that demonstrates the expected movements for the commands from the Duet guide:

After you have finished the stepper motors setup​, check the video below to see if your motor's orientation is correct. In this video i am clicking manually on the Jog buttons and your printer should move in the same direction as in the video:

Additional guides you can do:


There are several calibration processes that cannot be skipped. You must perform them exactly as shown in the following pictures. Please take the time to do this and perform all the steps with maximum accuracy. These steps have a huge impact on the end results.


Hotend PID

Small note about the Hotend PID. The picture below is the classic way for PID tune your Hotend. the new beta release offers a new algorithm which detects fan PWM changes and adjusts the heater in advance. to take advantage the new feature you would need to make a new PID using the new parameter. 
in order to use the new feature:

  • you would need to have the latest beta release 3.x.x version

  • all of your tools (T0) should be defined correctly.

  • Define your fans correctly according to RFF instructions.

  • Use M303 T0 S200 to start tuning your heater. you need to change the "200" to your normal printing temperature. make sure to turn off the layer fan before you start. the new algorithm will turn it on while tuning 

So, if you would like to use the new algorithm, Just replace the M303 H1 S190 with M303 T0S190



There are a number of additional features that you can enable and calibrate.

Be sure to read carefully each feature's guide before you calibrate and enable it:


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