Z probe stuck at 1000 with smart affector

  • my z probe in the web interface is stuck at 1000, when i tap the effector the strain Gage light turns on like its working. im enclosing config.g my fw version is 1.19-b6 (2017-05-19) and im using the 0.8.5 Ethernet version of the duet. do u guys have any ideas about whats going on?

    ; Configuration file for Duet 0.8.5 (firmware version 1.17)
    ; executed by the firmware on start-up
    ; generated by RepRapFirmware Configuration Tool on Mon May 22 2017 19:19:15 GMT-0500 (Central Daylight Time)

    ; General preferences
    M111 S0 ; Debugging off
    G21 ; Work in millimetres
    G90 ; Send absolute coordinates…
    M83 ; ...but relative extruder moves
    M555 P2 ; Set firmware compatibility to look like Marlin
    M665 L494.762 R249.273 H371.713 B150.0 X0.215 Y-0.498 Z0.000
    M666 X-0.309 Y0.608 Z-0.299 A0.00 B0.00
    M208 Z-10 S1 ; Set minimum Z

    ; Endstops
    M574 X2 Y2 Z2 S0 ; Define active low and unused microswitches
    M558 P5 R0.4 F1000 ; Set Z probe type to unmodulated, the axes for which it is used and the probe + travel speeds
    G31 P100 X0 Y0 Z-0.1 ; Set Z probe trigger value, offset and trigger height
    M557 R150 S30 ; define a grid with the specified radius and spacing (for delta printers)

    ; Drives
    M569 P0 S1 ; Drive 0 goes forwards
    M569 P1 S1 ; Drive 1 goes forwards
    M569 P2 S1 ; Drive 2 goes forwards
    M569 P3 S1 ; Drive 3 goes forwards
    M92 X80 Y80 Z80 E396.23 ; Set steps per mm
    M566 X1200 Y1200 Z1200 E1200 ; Set maximum instantaneous speed changes (mm/min)
    M203 X18000 Y18000 Z18000 E1200 ; Set maximum speeds (mm/min)
    M201 X1000 Y1000 Z1000 E1000 ; Set accelerations (mm/s^2)
    M906 X1000 Y1000 Z1000 E800 I30 ; Set motor currents (mA) and motor idle factor in per cent
    M84 S30 ; Set idle timeout

    ; Heaters
    M143 S260 ; Set maximum heater temperature to 260C
    M305 P0 T100000 B3950 C0 R4700 ; Set thermistor + ADC parameters for heater 0
    M305 P1 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 1

    ; Tools
    M563 P0 D0 H1 ; Define tool 0
    G10 P0 X0 Y0 Z0 ; Set tool 0 axis offsets
    G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C

    ; Network
    M550 PMy printer ; Set machine name
    M540 PBE:EF:DE:AD:FE:ED ; Set MAC address
    M552 P192.168.5.202 S1 ; Enable network and set IP address
    M553 P255.255.255.0 ; Set netmask
    M554 P192.168.5.1 ; Set gateway
    M586 P0 S1 ; Enable HTTP
    M586 P1 S0 ; Disable FTP
    M586 P2 S0 ; Disable Telnet

    ; Fans
    M106 P0 S0.3 I0 F500 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
    M106 P1 S1 I0 F500 H1 T45 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned on

    ; Custom settings are not configured

  • checked my wire resistance and no wires are crossed or broken.

  • Might unplug the hotend fan and see if it drops back to 0.

  • administrators

    Looks like you have a wiring problem. With P5 in the M558 command the pullup resistor is enabled, so you will get a reading of 1000 with nothing connected to the input pin.

  • cool, knowing that im guessing i miswired it, i pulled the 6 pin and its still at 1k


    is my wiering correct?

  • i updated the firmware to 1.19 checked the wiring, my z is still at 1000.
    i can send a M672 S131:131 and it blinks 5 times like its receiving commands.

  • administrators

    Your wiring looks correct. My guess is that you have a bad crimp connection at one end of the white wire; but there it could be a problem on the strain effector instead. So check the following on the strain effector:

    • That pin 5 of the 8-way connector (the pin that the white wire connects to) has been soldered on the underside of the board. That connector has to be hand soldered, so it's possible that a pin has been missed.

    • That resistor R5 is present and both ends of it are soldered down. It's on the underside of the board close to the 8-way connector.

  • i checked my crimps and that that resister was there and still 1000 in my z.

  • got it working, by using M558 P1 R0.4 F1000 X0 Z0

  • administrators

    That's odd. If it works with M558 P1 then it should work with M558 P5 as well, unless somehow the output resistor on the effector (R5) has much too high a value, or there is a bad connection in the output wire.

  • You have two M558.

  • Comment out the one in the Endstop with a colon ; and test it. Can always change it back.

  • administrators

    Unplug the 8-pin socket from the effector and push the 2 ends of a piece of wire into pins 5 and 6 of it. That should give a Z probe reading of zero. If it doesn't, then the problem is most likely a bad crimp connection in the cable, or a wiring error, or a firmware configuration error. You can check that by shorting together the IN and GND pins of the Z probe connector on the Duet. If that makes the reading go to zero, then the fault lies in the cable.

  • administrators

    I'm glad you solved it. I find it impossible to check by visual inspection that crimped cable connections are OK, so when I make PanelDue cables up for customers, I always check the cable with a multimeter, or by using it to connect a PanelDue to a Duet.

  • Hi, i have almost the same problem, that the probe is stuck at 1000. If i short pin 5 and 6 it goes down to 0. When i try setting using M558 P1it goes down to ~939. Any idea what the problem could be?

  • administrators

    Does the green LED on the smart effector behave normally?

    Are you shorting pins 5 and 6 on the effector itself to get the reading to go down to 0, or are you shorting them somewhere else?

    Is resistor R5 present on your effector and properly soldered? It should measure 1K.

  • The green led is behaving normally, it's blinking twice at boot-up and is green all the time when the reading is at 1000. It is when I've shorted the pins on the effector that i get the reading 0.
    The resistor R5 is present on the board and from what i can see it's properly solderd, but I havn't mesured its resistance yet, have to do it this afternoon.

  • The R5 measures to 996 ohm so it should be fine

  • administrators

    After blinking at startup, the green LED should be off, at least when the effector is stationary. If it's always on, then either the effector is faulty, or something (most likely one of the fans) is generating enough interference to trigger the sensor. If you disconnect the 6-pin cable that feeds power to the heater and fans and then power up, does the green LED still remain on? If so, then the effector is faulty and you should ask for a replacement.

  • You are correct, if I disconnect the fans the sensor behaves normally; its off after the initiall two flashes and then flashes if i tap the hotend with my finger.

    But since the fans are triggering a signal of 939 of 1024 I guess I'll just have to drop the sensitivity till the fans doesn't trigger it anymore

    Edit: I should add that I use the supplied 30mm fan for the hotend and the 40mm fan attached via your design:https://www.thingiverse.com/thing:2467663 if it helps someone else

  • administrators

    It is OK with just the E3D 30mm fan running? It doesn't matter of the print cooling fan interferes with the sensing, because you don't need to probe with the print cooling fan on.

    Is it a 12V or a 24V system?

    Make sure that both wires in the pair from the fan follow the same route to the connector. This should normally be the case, unless you have split the wires apart.

    Some people using large heatsink cooling fans have extended the heatsink fan duct to place the heatsink fan further away from the electronics.

    HTH David

  • No, on factory settings just the 30mm fan is triggering the sensor. The system is running on 12V.

  • How about turning the fan to get the wires coming out of it away from the effector?

  • administrators

    I agree, it looks to me that the separate red and black wires from the fan are running close to the amplifier on the effector. The separate red and black wires will create a magnetic field that will induce current in the electronics. You should route them at a greater distance from that part of effector PCB and preferably twist them together - although that's difficult with the fan connector already crimped on, so holding them next to each with twine or tape may be easier.

    Here's a photo of my effector and heatsink fan. You will see that the fan wires are close together and well away from the PCB.

  • I have sort of a combination of both cases discussed here:

    • the green D3 LED blinks twice on startup and is off if the effector is at rest
    • the LED blinks every time I tap the nozzle upwards
    • it blinks five times if I send the M672 S131:131
      However, the DWC reading is stuck at 1000 if I use the P5 type Z-Probe in my config.g.

    I have tried to Bridge the pin 5 and 6 on my cable loom on the effector side - no effect, if I Bridge the ground and Z-Probe in directly at the DUET 0.85 - result is the same, no effect on the Z-Probe reading.
    I have used a multimetrer tool to ring the wires, it seems I have a solid connection there.
    If I rewire the effector to use the IR Probe and reconfigure the config.g accordingly - the IR sensor works fine.
    it seems to me, that the FW is not liking the P5 type Z-Probe, or I have an interfering configuration somehow.

    If I set the M558 to P1, the Z-Probe seems to work (the G30 will be stopped by a gentle tap). Is it a valid solution? what is the difference between P1 and P5 then?

    I am on 1.19 FW, running a 1.19DWC and Duet 0.85.

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