Hephestos - new user questions and heated bed installation

  • Hi there,

    I was lucky enough to receive an i3 Hephestos for Christmas, which I have been greatly enjoying. Assembly was straightforward, and the whole family have caught the 3D-printing bug. However, I do have a couple of questions, which this forum seems like the right place for.

    Firstly, a simple one - the fan mounted above the RAMPS controller, though wired correctly, seems to be pulling air away from the board. This seems wrong - should it in fact be blowing cool air onto the board? This would be more effective for the heat-sinks.

    Secondly, the machine did not come with a heated bed. I have now ordered and received one, but I am having some trouble getting it to work. There are several versions of the instructions available, though I think I have worked out the mechanical and electrical installation. However, it has not been possible to upgrade the firmware on the RAMPS - I downloaded the .ino file suggested by the instructions, but unfortunately the Arduino IDE gives me nothing but timeout errors when I try to upload it. Could someone please confirm whether the firmware upgrade is necessary, and what steps I should try in order to fix this problem?

    Thanks for your help!

  • 3 Commentssorted by
  • A Ossorio
    A Ossorio
    Moderator  (198)
    Hi @gbsallery,

    Thank you for your post.

    You are quite right: the fan should be directing the air towards the RAMPS and not away from it. Something must be wrong with your set-up.

    In any case, since you also need help with the heatbed set-up, we are going to contact you privately to provide you with detailed instructions on how to set it up. The firmware upgrade is definitely necessary.

    You will receive an email from BQ technical support shortly.

    A. Ossorio

    BQ Technical Support

    Official Support Channels:       Phone Assistance Monday to Friday from 8:00 to 17:00        Formulario-de-soporte_inglaterra.png
  • A Ossorio
    A Ossorio
    Moderator  (198)
    Hi @gbsallery,

    We have an article on how to assemble the heatbed on the Prusa i3 Hephestos:
    How to install the Heatbed on your Prusa i3 3D printer

    It provides very good guidance for the assembly of the heatbed. However, about the firmware update, please check my comment of 11 January just below that article, where I describe in detail our recommended way of compiling and uploading the firmware to your printer.

    About the installation itself, you should carefully follow the connections diagram.

    There are a couple of things that you should also take into account:

    - You first need to replace the original PSU (Power Supply Unit) with a more powerful one. It will have to be 12V exactly, and then a least 300W and 25A.

    - You should ensure that the PSU is connected correctly to the green connector on the RAMPS board. Check that the four pins of the green connector have tension, are positively and securely connected, and its polarities along the four pins are: (+) (-) (+) (-).

    If you still have any issue along the process or something does not quite work as expected, please send us a private message and we will provide you with assistance to get your specific set-up to work.

    A. Ossorio

    BQ Technical Support

    Official Support Channels:       Phone Assistance Monday to Friday from 8:00 to 17:00        Formulario-de-soporte_inglaterra.png
  • Hi. gbsallery.

    I was also given a heated bed for xmas. here are the steps I followed to get it working on my BQ Prusa i3. 8-)

    (disclaimer, I did it this way, this is not an official BQ method, if you are not confident with PC PSU alterations, please use another PSU such as a laptop one)

    1) Get a PC ATX PSU of at least 350w capacity, this replaces the BQ supplied black PSU.
       essentially, you need to connect the GREEN lead to one of the -ve black cables to make the PSU come on
       (I used a little switch) you need to get around 4 of the yellow (12v) cables off one of the connectors (e.g the hard-disk power connectors) and connect them together to ensure you have sufficient current to the i3, and 4 black cables for the - connector as well.

    3) connect the power as A.Ossario says above + - + - on the RAMPS board - you will be connecting up both the power block connections that are already used by the BQ PSU, and the ones next to them which supply the heated bed.

    4)  solder your heated bed + and - with the thick cables that came with it, and add one or two LED diodes if the contacts are on the bed, at least one of these will light to tell you the heat is on. - I used this guide as no instructions came with my heated bed. Solder the thermocouple with the thin wires, and connector on the other end. I stuck mine into the central hole with a hot-melt glue gun (glue melts at 160c) so its fine

    5) get a cork tile from Wikes or somewhere, and cut a little from the front so that the heated bed sits flush on it with a small cut-out for the cables from the heated bed (all soldering should be on the bottom as per link above, so the top is smooth. I also cut a small channel for the thermocouple sensor cable to the front as well, and applied a little more hot-melt glue round the thermocouple to stick the cork tile on to the heating mat a little as well. The PCB tracks for the heat element should be at the top of the bed, and the soldering underneath. 

    6) I put the big plastic printer base to one side, and installed it like this:

        - glass sheet
        - heated bed (soldering on underside, tracks on top)
        - Wikes cork tile
        - bolts and springs through the lot and screw to the sliding printer bed base.

    7) Now the RAMPS firmware... 8-)

    - connect the Arduino board to the PC with Arduino IDE installed.
    - Power up the printer as normal (with or without heated bed connected, it just needs to boot)
    - find the serial port (use Tools/Serial Monitor) to test it  select 115200 baud. - When you find the printer and its on, the serial monitor will print out loads of G-Code as the printer starts up, and show more as the printer sits there waiting for you every few seconds. Until you can see G-Code in the serial monitor , your USB-Serial driver is not working, and you wont be able to progress. - possible messing with drivers required, or re-installing older arduino IDE package from arduino.cc (I used 1.65 and it was fine in Win10 x64)

    - download the https://github.com/bq/Marlin firmware 

    Recently, it was updated to work on all their printers, as you'd imagine, hence the changes I had to make are a bit different to what I found published. Specifically BQ (I think) have added a make script that does everything for you, complile and flash etc - so you can close the Arduino IDE as you dont need it running.

    - so you dont use the IDE to do this, you use the makefile:

       - download GNU Make for Windows and install somewhere
       - My Arduino folder wasnt in the right place, so I had to move it - if you get an error later, try copying it to c:\Arduino
       - Unzip the code zip file
       - find \Marlin\config\hephestos folder
       - edit Configuration.h  (link to my working code that I flashed to it on dropbox here, or just the config file I used)
          - there are several sections you need to modify to enable it: 


    #define TEMP_SENSOR_BED 0
    #define TEMP_SENSOR_BED 1

        - save the file
       - open a command prompt as administrator
       - cd \<wherever your marlin folder is>
       - run 'make.cmd' - answer the questions, including which com port you're attached to.
       - if you have the Arduino IDE in the right place, and the GNU make in the right place, it should run and ask you which printer model you have, and the serial port.
       - it will then compile and flash the firmware.

    8) Again, power up your printer with new PSU, or old one to check firmware provided bed is disconnected.
       - you should notice a new square with (H) in it at the top of the LCD and with it a temperature readout in addition to the one you normally see for the extruder.

    9) Cables etc, new PSU and plug in and switch on.

    Now, I use CURA as my slicer, but essentially any OLD g-code files you have on the SD card from before wont activate the heated bed, as the G-Code for the bed temperature etc is missing from them. So I did this:

    In Cura:

     -  Machine/Settings
     - tick the box next to 'heated bed' and click OK.
     - now Cura should show 'Speed And Temperature' on the left with the addition of 'Bed Temperature'
      - I am printing great on the BQ Cura Profiles, with 50mm/s speed, 220c Extruder (PLA), and 70c Bed Temperature.

    Only other thing I needed to do was level the bed again (sigh), paper is tight under mine, but will pull out, and clean your glass bed with some isopropyl alcohol to make sure its not greasy from your fingers re-assembling everything.

    Do a test print - the bed LED should light up, or if you use OctoPrint over USB, you can send a M140 S50 to heat it to 50c , the LED should come on and the temperature should rise on the display. M140 S0 will turn it off again.

    I get poor adhesion below 70c with the glass plate, some people I know print direct on the heated bed itself at lower temperatures. it takes about 15 mins to get to 70c from ambient room temp for me.

    hope it works ok for you 8-)