When I leave my printer idle for more than 30 minutes, it starts making a 15,500 Hz sound that's quite prominent and goes away with any load (eg heater on). Interested as to what causes this, I assume it's some sort of standby state from either the duet or the power supply itself?
Just curious if there's anything I can do to stop it. My (or my dog's!) ears don't appreciate it 
@dc42 I'll definitely move to AC bed in the future for sure. For now I've put two layers of cork on the underside of the bed which has now increased my max bed temp up to 105C. Can heartily recommend this to anybody also struggling with this issue.
@dc42 Cheers for getting back to me! I'm getting 23.9 V at the bed, so close enough. Good to know that's roughly in line with what you'd expect to see. I've just got some ASA which wants more like 110, so could be time to move to a 220 V bed instead.
I've got a Duet 2 wifi for hardware.
I've got a 220 x 220 mm PCB heated bed with an aluminium plate on the top (Link) which tops out at 87 degrees.
I get 4.8 ohms measuring across the ends of the wires running to the bed (when they're disconnected from the duet), and when it's plugged in I get 24.2 V across the contacts, which should be 120 W of heating. As a check I've tried measuring the current across the contacts when heating at full power and I only get 0.4 A which doesn't seem right to me.
I've run pwm tuning and the results are here
M307 H0
Heater 0 model: gain 77.1, time constant 411.2, dead time 3.0, max PWM 1.00, calibration voltage 23.0, mode PID, inverted no, frequency default
Computed PID parameters for setpoint change: P317.3, I9.035, D666.4
Computed PID parameters for load change: P31
Any thoughts as to why I'm not getting the expected heating performance?
Are you saying there is more than 1 endstop switch for z?
So after some experimentation, I've found that I don't get issues when extruder jerk is at 120mm/min and accel is at 3500 mm/min. This however slows down a print a fair bit (calibration cube took 19min20 instead of 15:42).
I've tried lowering microsteps to x8 and x4 but it just makes such a lot of noise that I don't think I want to have it like that even if it works!
@CCS86 doesn't a jerk setting that low really slow down your print? I see lots of other people using 3000 jerk on the same extruder is the thing too.
@deckingman I've just done a run of a print where it's been doing the blobbing, and didn't get any hiccups recorded 
Just a shot in the dark really, what setting do you have the thumbscrew on for your BMGs with PLA? The instructions said to tighten all the way and undo 1.5 turns, but that seems far too tight?
@deckingman It's a clone, but the extruder works fine by hand and I've checked the grub screws are good.
I found my pressure advance value by doing this ringing print https://www.thingiverse.com/thing:4169896 and found that somewhere between 0.3 and 0.4 was my good value. You can see that the ringing is reduced on the Xs, but at 0.4 and 0.5 the corners start to go inconsistent.
So you're suggesting that setting extruder jerk low is just mitigating the problem and isn't actually solving it, as extruder jerk shouldn't be the limiting factor?
At extruder jerk of 300 I still can't get it to be consistent, it's only at 100 that I get better results, but that is extremely slow.
@bberger said in Pressure advance causing underextrusion/motor madness:
50mm wall. What happened was: it ended up extruding and retracting so much that it basically tried to extrude 25mm and then directly rectracted the same 25mm so on and so forth. In the end nothing came out of the nozzle anymore and all that was happening was constant extruding/retracting.
This is similar to the issue I'm ending up with. At a point where it is underextruding, it's as if it's ended up doing more retractions than it has unretractions, as the filament is no longer at the end of the nozzle. It then feels like it "catches up" and produces a blob. I have had issues with this in the past even with PA off, but I thought I'd fixed that. PA seems to make it far worse.
At the point where it produces a big blob, I can hear the "pop" sound you get when the filament first comes out of the nozzle.
I'll try using a Titan extruder instead and see if that makes any difference.
(I'm also running with DAA off)
@deckingman The thing is, here's exactly the same tower printed just afterwards with PA off, and it's fine (minus the stringing!)
So I cleared the hotend out to make sure there was nothing blocking it, limited the max E speed to 8000 and tried a retraction tower. This is what I got from increasing the retraction distance from 0 to 10 mm (in 0.5 mm increments, feedrate 2000 mm/min).
The towers aren't all that round, which suggests that the extrusion amount is not consistent. There are parts where it's thinner, then the large blobs where it adds up. This is odd as every layer should be exactly the same, so if it's a situation of partial jamming as @deckingman suggests, I don't know what would cause it to unjam on those layers.
@Phaedrux presumably this should in theory print fine with PA on?
A similar issue as described here in this previous thread. Re: Extruder motors skip steps with pressure advance enabled. I can print just fine without pressure advance enabled, but when I turn it on (S0.35 found from testing) the prints get areas of total underextrusion, and then big blobs.
I have tried increasing and lowering motor current, different slicers, and modifying jerks . The only thing that helps is if I lower the extruder jerk all the way down to 100, but this then slows the print dramatically.
When PA is enabled, I can hear loud noises from the extruder, and commonly the filament ends up being ground to where it won't drive anymore.
Settings:
M350 X16 Y16 Z16 E16 I1
M92 X80 Y80 Z400 E412
M203 X30000 Y30000 Z1500 E18000
M201 X2000 Y2000 Z240 E3000
M566 X1000 Y1000 Z120 E3000
M572 d0:1 s0.35
This is an example of what I'm seeing on a 75% scale Benchy, 0.1 layer height, 60mm/s max print speed. You can see the overextrusion on the lower layers, then it's ok for a bit, then under followed by overextrusion, then underextrusion to the point where it jams and the print fails.
@zapta
What I've done for now is just mark out on the slicer where the unusable areas are. The mesh probe currently only does a rectangle where it isn't constrained by those points.
Due to the shape of my printer/toolhead, there are specific points on the bed that the probe cannot reach. However, later on down the axis it is able to reach them, so am I able to exclude points from a mesh level?
e.g. I want to mesh level from X0:200, Y0:200 s20 but exclude (0,0) and (200,0)?!
@Phaedrux is 2.05.1 the latest firmware? 3.01 is the last one on the github?
This is with a duet 2 wifi 1.02 running firmware 2.02, web interface 1.21
; generated by RepRapFirmware Configuration Tool on Wed Sep 19 2018 20:20:59 GMT+0100 (British Summer Time)
; General preferences
G90 ; Send absolute coordinates...
M83 ; ...but relative extruder moves
M667 S1 ; Select CoreXY mode
; Network
M550 PHypercube ; Set machine name
M552 S1
M586 P0 S1 ; Enable HTTP
M586 P1 S0 ; Disable FTP
M586 P2 S0 ; Disable Telnet
; 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 (was backwards pre 6/4/19)
M350 X16 Y16 Z16 E16 I1 ; Configure microstepping with interpolation
M92 X80 Y80 Z400 E412 ; Set steps per mm was 420 original, now 412 of 26/04/19
M566 X1000 Y1000 Z50 E3000 ; Set maximum instantaneous speed changes (mm/min) was 400x 400y 15/12 e was 150 as of 15/12 z was 12 as of 10/01/20
M203 X30000 Y30000 Z1000 E18000 ; Set maximum speeds (mm/min) z was 500 as of 12/04/20
M201 X1000 Y1000 Z60 E3000 ; Set accelerations (mm/s^2) was X1000 Y1000 z was 120 as of 10/01/20
M906 X1200 Y1200 Z1200 E1500 I30 ; Set motor currents (mA) and motor idle factor in per cent
M84 S30 ; Set idle timeout
m572 d0:1 s0.0 ;add pressure advance if wanted
m584 z2
; Axis Limits
M208 X0 Y0 Z0 S1 ; Set axis minima
M208 X200 Y200 Z200 S0 ; Set axis maxima
; Endstops
M574 X1 Y2 S3 ; Set endstops controlled by motor load detection
M591 d0 p1 c3 s1 ;enable filament run out for e0, low when present, extruder e0 endstop
; Z-Probe
m558 p5 I1 H3 F200 T18000 R0.1 b0 for picking up probe module
G31 P50 X-27 Y17 z23.75 ;Set Z probe trigger value, offset and trigger height.
M557 X0:173 Y17:200 S30 ; Define mesh grid
; Heaters
M305 P0 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 0
M143 H0 S120 ; Set temperature limit for heater 0 to 120C
M305 P1 T100000 B4138 C0 R4700 ; Set thermistor + ADC parameters for heater 1 (was temp. 3950)
M143 H1 S280 ; Set temperature limit for heater 1 to 280C
; Fans
M106 P0 S0.0 I0 F100 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned on fan at 50%
M106 P1 S0.0 I0 F100 H-1 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P2 S255 I0 F500 H-1 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned off
; 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
M570 H1 P10 T15
; Custom settings are not configured
m501 ;yes they are
My homing routine is as follows. I've indented the macros that are called:
M915 Y S5 R0 F0 ;y homes first to ensure that X homes centrally
M915 X S5 R0 F0
M400
M574 Y1 S3
M913 X75 Y75
G91
G1 S1 Y-700 F4000
G90
M400
M913 Y100
G1 y100 f6000
M915 X S5 R0 F0 ; x home
M400
M574 X1 S3
M913 X75 Y75
G91
G1 S1 X-700 F4000
G90
M400
M913 X100
G1 X0 F6000
M915 Y S5 R0 F0 ;y home
M915 X S5 R0 F0
M400
M574 Y1 S3
M913 X75 Y75
G91
G1 S1 Y-700 F4000
g92 y20
G90
M400
M913 Y100
G28 Z
####### G28 Z ########
m98 P"/Macros/pick_up_probe"
########## pick_up_probe ######
G92 Z90 ;set Z height so that axis will move unhomed
g91
G1 Z10 F500 ; drop Z so module can be picked up
G90
g1 X8.1 Y169 F30000 ;move to probe pickup
m574 z1 s2 ;configure endstop type for switch
m558 p5 I1 F100 T6000 R0.6 b0 ;configure probe for picking up module
G1 Z-999 F150 H1 ;dive z until picked up module
G91 ;relative moves
G92 Z30 ;set z axis to rough z position
G1 Y22 F300 ;remove probe from holder
G1 Z38 F2000 ;drop z to account for new probe height
G90 ;absolute moves
G1 X100 Y100 f30000 ;move to probe point
M558 p8 I0 H1.5 F1000 T18000 R0 b0 ;configure probe for probing
G30 ;do coarse home
######back to G28 Z#####
m300 s880 p100 ;beep to signal probe contact
g4 p120 ;dwell to wait for beep
m558 f50 ;reduce feed rate for fine probe
g30 ;probe z
m300 s880 p100 ;beeps again
g4 p200
M558 F600 ;put feed back to normal
;G29 S0 mesh level if wanted
m98 P"/Macros/put_down_probe"
########### put_down_probe #########
G1 Z27 ;move to Z height
G1 X40 Y185 f30000 ; go to probe put down position, avoiding the probe module (hence two individual moves)
G1 X8.1 f30000
G1 Z3.5 F600 ;move to z height for module put down
G1 Y180 F200 ;feed slowly into probe holder
G1 Y169 F100
G1 Z25 F200 ;increase Z to drop probe
m574 z1 s2 ;configure endstop type for switch
m558 p5 I1 F100 T6000 R0.6 b0 ;configure probe for picking up module
g1 x100 y100 f6000
#####end of put_down_probe####
#####end of G28 Z ######
#####end of home all #####
I appreciate there are a lot of lines in there! Thanks for your help!
I've got two issues that may be related. The first is that when I do a G28, even though it homes successfully, it gives "Error: Homing failed" back in the console. My homing routine is as follows:
Could it be something to do with using macros?
My second issue is that the print status then goes to 100% complete immediately and gives no estimations for finishing time.
So just for if anybody looks back to this from a google search and for documenting it solved this issue (don't worry it didn't take 4 months!).
At the time I was using a precision piezo on the hotend using the printed mount. The bowden coupler that I had wasn't holding the tube firmly enough (even with a collet clip in there), so when I was retracting, the tube was being pulled up and away from the hotend. When enough extruding was done to push the tube back down is where a splurge would occur.
I figured this out by marking the bowden tube with some pen, and watching it move slightly further out with each retraction. I've now changed the mounting method (and z homing method too) and all is well!
Just in case anybody wants to do this in the future, I've solved it. The issue with having it not move when using G1 Z-999 H1 was my M574 needed to be set as a probe (Z) and I used the Z probe input pins. I had previously been trying the Z probe pins with S1 and the Z endstop pins with S1 (unsure as to why the endstop pins with S1 didn't work.)
At some point I'll show the new probing method...
@infiniteloop So I've just given this a go. With it configured to use a switch as the end stop, using the H1 part of the G1 command means the axis doesn't move. If I don't have the H1 parameter then it does move. i.e.
G1 Z10 H1 ; no movement
G1 Z10 ; moves 10 in Z
This is with the configuration M574 Z1 S1 and no M588 in the config.g