stepper artefacts

  • Hi my question is, i have a machine based on nema 23 and i control them with drivers connected to expansion header. when the printer drives a circle then the noise of the steppers will be louder ( when two or more axies will be work at the same time). is it possible that the cpu timing is to slow for 7 external drivers (not on duex 5)?
    it will be nice if someone can help me !
    PS the T parameter in M569 is correct ! (2.5)

  • Instant speed setting can have a significant effect on noise when the machines traverse arcs.

    Motion section of the config? Acceleration, steps per mm, max speed, instant speed,etc?

  • thank you first for answering but this is not the problem. there is no hard acceleration and not much jerk at that movement, it looks like that all axies are cut some signals at every movement at the same time inc. the extrusion stepper.

  • the movement looks like doing one section-stop-doing a section-stop untill the rounded corner is done?

  • administrators

    Run M122 and check the Hiccup count to see whether the problem is that steps can't be generated fast enough. Unfortunately, for external drivers extra delays need to be inserted (controlled by the T parameter), which reduces the maximum step rate.

    It's better to choose the Nema 23 motors carefully so that they can be driven directly by the Duet.

  • @dc42 said in stepper artefacts:

    t's better to choose the Nema 23 motors carefully so that they can be driven directly by the Duet

    There is th M122


    === Diagnostics ===
    RepRapFirmware for Duet 2 WiFi/Ethernet version 3.0beta12 running on Duet Ethernet 1.02 or later
    Board ID: 08DGM-9T6BU-FG3SN-6JKDL-3SJ6S-18WZH
    Used output buffers: 1 of 24 (18 max)
    === RTOS ===
    Static ram: 25812
    Dynamic ram: 98280 of which 32 recycled
    Exception stack ram used: 508
    Never used ram: 6440
    Tasks: NETWORK(ready,764) HEAT(blocked,1240) MAIN(running,3688) IDLE(ready,200)
    Owned mutexes:
    === Platform ===
    Last reset 00:04:16 ago, cause: software
    Last software reset time unknown, reason: User, spinning module GCodes, available RAM 6440 bytes (slot 2)
    Software reset code 0x0003 HFSR 0x00000000 CFSR 0x00000000 ICSR 0x0041f000 BFAR 0xe000ed38 SP 0xffffffff Task 0x4e49414d
    Error status: 0
    Free file entries: 9
    SD card 0 detected, interface speed: 20.0MBytes/sec
    SD card longest block write time: 0.0ms, max retries 0
    MCU temperature: min 33.1, current 35.6, max 35.6
    Supply voltage: min 24.7, current 25.0, max 25.2, under voltage events: 0, over voltage events: 0, power good: yes
    Driver 0: standstill, SG min/max 0/634
    Driver 1: standstill, SG min/max 0/682
    Driver 2: standstill, SG min/max 0/574
    Driver 3: standstill, SG min/max 0/698
    Driver 4: standstill, SG min/max not available
    Date/time: 2019-11-17 13:07:29
    Cache data hit count 498546332
    Slowest loop: 52.27ms; fastest: 0.08ms
    I2C nak errors 0, send timeouts 0, receive timeouts 0, finishTimeouts 0, resets 0
    === Move ===
    Hiccups: 0, FreeDm: 166, MinFreeDm: 111, MaxWait: 10882ms
    Bed compensation in use: none, comp offset 0.000
    === MainDDARing ===
    Scheduled moves: 817, completed moves: 814, StepErrors: 0, LaErrors: 0, Underruns: 0, 0
    === AuxDDARing ===
    Scheduled moves: 0, completed moves: 0, StepErrors: 0, LaErrors: 0, Underruns: 0, 0
    === Heat ===
    Bed heaters = 0 -1 -1 -1, chamberHeaters = -1 -1
    Heater 1 is on, I-accum = 0.0
    === GCodes ===
    Segments left: 1
    Stack records: 1 allocated, 0 in use
    Movement lock held by null
    http is idle in state(s) 0
    telnet is idle in state(s) 0
    file is doing "G1 X132.047 Y743.896 E9.7239" in state(s) 0
    serial is idle in state(s) 0
    aux is idle in state(s) 0
    daemon is idle in state(s) 0
    queue is idle in state(s) 0
    autopause is idle in state(s) 0
    Code queue is empty.
    === Network ===
    Slowest loop: 35.77ms; fastest: 0.01ms
    Responder states: HTTP(0) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0)
    HTTP sessions: 1 of 8
    Interface state 5, link 100Mbps full duplex

  • administrators

    You need to run M122 after you have done some moves and had the problem.

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