New Duet Wifi on old printer



  • I'm in the process of converting my core xy dual extruder printer (M3D Promega) to a single Bondtech/E3D V6. The original control board (Duet Maestro) had smoked drivers due to let's just say high G adjustments out of frustration. Ok....so here's where I'm at:

    I have purchased a new Duet Wifi, BL touch, Bondtech direct drive extruder, NEMA 17 extruder motor with .9° step angle, and E3D V6 hotend. I printed out and assembled the new mount from Thingiverse https://www.thingiverse.com/thing:3611643. I have connected the board to my PC via USB using YAT and enable Wifi and checked firmware version per the Duet3D documentation. Not sure why I had to do this but I did it. I then connected via the Web Interface and upgraded the board firmware to Release 2.04. I then upgraded the Web interface to 2.04. I installed the board and connected my 24V power supply and all the wires that go to the print head. All motors X, Y, Z are the same motors that came with the machine. The extruder motor is a replacement for the existing motor at the suggestion of the retailer Filastruder. But right now, the carriage assembly is still connected to the belts and the bed has been repositioned somewhere close to level since it got jolted prior to all of this.

    There is an existing file structure for the original Promega that was originally set up by M3D and the community. My goal here is to just start from scratch using the Duet documentation. And I've been doing so up to this point.

    I'm getting a little bit lost in the whole process and could use a little guidance before I start crashing things and getting mad all over again. My hope here is to learn how to set up a new printer using the Maestro. So far so good.

    So basically, I am connected to the Duet Wifi successfully. I'm wondering what is the next step. The Duet documentation has a way of flinging me all over the place not rembering where I came from. Being old school internet, I'm not accustomed to links taking you off the page you were studying only to get lost down a rabbit hole forgetting where you came from.

    At this point, I'd like to see if I can get all the motors to respond manually and I'm not sure if I can do that without a complete config.g file. I have been to the firmware configurator and was trying to figure out how to cross reference previous Promega settings to fill in the blanks on the new configuration tree. For example, were any of my motors reversed? Do I need to reverse my new extruder motor? What are the top speeds and the current settings of the eexisting motors on board the printer. Since the original extruder was a 1:1 and the new is a 3:1 (I think), where do I compensate for that? I look through the previous SD files and have sort of an idea but some of these numbers look pretty way out of the defaults of the configurator.

    So like I said...so far so good. I'm able to connect to the board and just wondering if I can apply power and test the motors heaters etc manually. OR...is there a better approach at this point? Thanks.



  • @jdjeff58 Ok...here's a specific question. Assuming that the bondtech has an e-step value of 415, how do I set the speeds of the new extruder motor. Here is the gcode of the original 1:1 extruder and I'm also assuming these are in mm/min not mm/sec as in the configurator.

    ; machine_stepperspeed.g
    ; June 29, 2018

    ; This sets the different speed limits of the X Y and Z steppers.
    ; A higher acceleration value makes for faster print speeds, but can also introduce ghosting and other artifacts.
    ; The maximum linear speed should only be changed if hardware has changed
    ; The maximum instantaneous speed change determines how slow the print head has to move before it can make
    ; abrupt direction changes.
    ; These are advanced feature values and should only be changed for good reason and if you know how they impact prints.

    M201 X500 Y500 Z75 E250:250 ; Set accelerations (mm/s^2)
    M203 X4200 Y4200 Z2300 E5000:5000 ; Set maximum linear speeds
    M566 X400 Y400 Z40 E300:300 ; Set maximum instantaneous speed changes (mm/min)


  • administrators

    @jdjeff58 said in New Duet Wifi on old printer:

    Since the original extruder was a 1:1 and the new is a 3:1 (I think), where do I compensate for that?

    In the E parameter of the M92 command. The 415 steps/mm you quote assumes a 1.8deg motor, so as you are using a 0.9deg extruder motor you will need to double it.

    Your speeds and accelerations look very conservative to me except for the maximum extruder speed of 5000mm/minute, so they should still work apart from that one.



  • @dc42 When I ran the configurator, it was asking for mm/sec. Was I correct in dividing the original values by 60 to get mm/sec. My new numbers for the 3:1 bondtech look like this:
    ; Drives
    M569 P0 S1 ; physical drive 0 goes forwards
    M569 P1 S1 ; physical drive 1 goes forwards
    M569 P2 S1 ; physical drive 2 goes forwards
    M569 P3 S1 ; physical drive 3 goes forwards
    M584 X0 Y1 Z2 E3 ; set drive mapping
    M350 X16 Y16 Z16 E16 I1 ; configure microstepping with interpolation
    M92 X79.80 Y79.80 Z282.70 E415.00 ; set steps per mm
    M566 X420.00 Y420.00 Z39.60 E120.00 ; set maximum instantaneous speed changes (mm/min)
    M203 X4200.00 Y4200.00 Z2298.00 E1200.00 ; set maximum speeds (mm/min)
    M201 X500.00 Y500.00 Z75.00 E250.00 ; set accelerations (mm/s^2)
    M906 X800 Y800 Z800 E800 I30 ; set motor currents (mA) and motor idle factor in per cent
    M84 S30 ; Set idle timeout

    Now wait a minute...what happened with the configurator asking fo mm/sec?


  • administrators

    Those numbers look OK to me except that your Z max speed in m203 may be a little high (depending on how the Z axis is driven) and the E max speed in M203 could probably be increased to 2000 or 2000. Also as I mentioned before, if your extruder motor is 0.9deg then you need to double the M92 E value.



  • @dc42 said in New Duet Wifi on old printer:

    Those numbers look OK to me except that your Z max speed in m203 may be a little high (depending on how the Z axis is driven) and the E max speed in M203 could probably be increased to 2000 or 2000. Also as I mentioned before, if your extruder motor is 0.9deg then you need to double the M92 E value.

    I changed the steps per mm to reflect .9 deg. The Z max speed is the original max speed (2300). The only thing I can say about that is that the Z bed is belt driven with a small pulley on the z motor and a larger pulley on the main shaft of the drive gear. I'm going to guess it's 3 times larger than the motor shaft pulley. When you say E max speed could be increased to 2000 or 2000 that looks like you meant to type something different....yes? Thanks.


  • administrators

    @jdjeff58, I meant 2000 or 3000. And as your Z axis is belt driven, that explains why it can do a high Z speed.


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