Extruder motors won't run faster than 5mm/s



  • I'm stumped with a strange problem here. I have an I3 style project using the Quadfusion Print head, a Duet2 Wifi and Duex 5 running the new RepRap 3.0 firmware. The problem I am having is under extrusion. What I've found is that while manually purging filament thru the nozzle via the DWC I cannot extrude OR even RETRACT faster than 7mm/s. Anything faster than 7mm/s and neither of the 4 extruders will even respond. Not stuck, not skipping steps, or even a clogged nozzle, no motor movement at all. I am using the factory .35 M3D nozzle, the drivers are not overheating, and I'm using PLA with 215c to 220c nozzle temp. Any help or ideas would be much appreciated.

    my drive config looks like this QuadFusion_config.g
    ; Drives
    M569 P0 S0 ; physical drive 0 goes backwards X axis
    M569 P1 S1 ; physical drive 1 goes forwards Y axis
    M569 P2 S0 ; physical drive 2 goes backwards Z1 axis
    M569 P3 S0 ; physical drive 3 goes backwards CYAN EXTRUDER
    M569 P4 S0 ; physical drive 4 goes backwards MAGENTA EXTRUDER
    M569 P5 S0 ; physical drive 5 goes backwards Z2 axis
    M569 P6 S1 ; physical drive 6 goes forwards YELLOW EXTRUDER
    M569 P7 S1 ; physical drive 7 goes forwards KEY EXTRUDER

    M584 X0 Y1 Z2:5 E3:4:6:7 ; set drive mapping
    M350 X16 Y16 Z16:16 E16:16:16:16 I1 ; configure microstepping with interpolation
    M92 X80.00 Y80.00 Z400.00:400.00 E1968.00:1968.00:1968.00:1968.00 ; set steps per mm
    M566 X600.00 Y600.00 Z18.00:18.00 E1000.00:1000.00:1000.00:1000.00 ; set maximum instantaneous speed changes (mm/min)
    M203 X6000.00 Y6000.00 Z600:600 E8000.00:8000.00:8000.00:8000.00 ; set maximum speeds (mm/min)
    M201 X1500.00 Y1500.00 Z100.00:100 E10000.00:10000.00:10000.00:10000.00 ; set accelerations (mm/s^2)
    M906 X1000 Y1000 Z1100:1100 E500:500:500:500 I30 ; set motor currents (mA) and motor idle factor in per cent
    M84 S45 ; Set idle timeout



  • Hi,

    Have you tried upping the motor currents?

    Frederick


  • Moderator

    Can you send M122 after you experience this?

    Your e steps are quite high and the acceleration is quite high, so I'm wondering if you're getting any hiccups which would be reported in M122.

    Try reducing your E accel.



  • @fcwilt Motor currents are just about maxed out for these little guys



  • @Phaedrux Yeah, Jerk and accel are really high because I was trying different things to see if I could get a response. Esteps are calibrated. It will extrude accurately just slowly. I've since pulled the jerk and accel way down to 1000 and 200 and am still looking.



  • @KenD Lower them to the bare minimum for testing. See if you can hit 10 mm/s (without filament) with the jerk at something like 1 mm/s and the accel at like 100 mm/s.

    If your jerk is set to 15 mm/s, acceleration never comes into play (when commanding below 15 mm/s speeds). that's not true because jerk only comes into play during a retract or the like.



  • I ordered a new nozzle from M3D a few moments ago. These nozzles have a 2 piece steel and PTFE liner inside them and I cant get them apart. I'm hoping the quad PTFE liner is just melted inside.



  • installed a new nozzle and I've set jerk to 1mm/s and accell to 50mm/s and it still won't extrude faster than 5mm/s


  • Moderator

    @KenD said in Extruder motors won't run faster than 5mm/s:

    it still won't extrude faster than 5mm/s

    And that's with no filament loaded?



  • @Phaedrux Without filament loaded I can run all the extruders as fast as I want. So to eliminate the possibility of the nozzle being the problem I removed the nozzle and heat block completely, loaded all 4 filaments into the print head and disabled cold extrude checking in Duet via M302 P1. All 4 motors respond the same, after 5mm/s they fail. They begin to extrude or retract at higher speeds like 60 or 80 mm/s and then just quit moving. And to confuse matters more you can still hear the motors making a whining noise after filament stops moving. Could the drivers on Duet be bad? This is brand new Duet 2 and Duex 5.

    I am noticing now that every once in a while it will actually extrude properly. i replaced one of the 4 motors and have the same results. 2 of the extruders are on the Duet and the other two are on the Duex5. Really starting to seem like a board issue.



  • @KenD is this a mixing extruder? What's the gearing on the motors? How is that done? What is the maximum current rating of the motors?



  • I just read the specs on that extruder and noticed that they state it comes with a pt1000 thermistor...Looking at your config it appears you have your thermistor configured like a normal E3D cartridge thermistor, could it be that you have your thermistor set incorrectly so the temperatures reported are incorrect?



  • @KenD Could it be that whatever hobbed bolt arrangement is used to grip the filament is slipping on the motor shaft? It would explain why you can hear the motors after the filament had stopped extruding.
    For info, the only Quad I saw running a demo print was soooo slow. Maybe 5mm/sec extruder speed is the max that those tiny motors can do.


Log in to reply