Too much layer shifting
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I had to drop my accel and jerk down to the levels of a standard prusa to keep my layer shifting from occuring and I've been slowly upping my speed back up to around 100mm/s.
Also running a corexy machine, C-bot
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I'm thinking to downgrade firmware to the 1.15a or b. Did you try previous version ?
Shifting occurred without the pressure advance function but less than with… Today i've got 2 shifiting with 5 prints launched. I'm not sure about this but it tends to shift in infill parts and small segment,
i will try tomorrow to record a print.Thanks Sniffle for your post, i felt alone in this problem and i didn't relaunch this thread thinking i'm just unlucky... ; -)
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I still think your layer shifting problem has a mechanical cause. The only layer shift issues that I recall anyone else reporting since many months ago were associated with particular values of pressure advance. They were due to a bug in the pressure advance calculation coupled with a bug in the error handling that meant that when the first bug was triggered, unless you had Move debug enabled then no step error was recorded and a layer shift resulted. Both bugs were fixed in 1.15e. If there is another similar step generation bug that is capable of causing layer shifts, the error handling will record a step error.
But by all means try reverting to an older firmware version to see if it makes any difference.
Your acceleration and jerk values look high to me. Try 3000 accel and 600 jerk. Also, please can you provide your motor specifications, your steps/mm, maximum travel speed you are using, motor current you have set, and Vin supply voltage. From those I can work out whether you are losing motor torque at high speeds.
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Hi David,
I'm testing your board since the beginning, i like it and possibilities offers by your work.
I'm posting this because something change in motion resulting those shifted layers and i will not post this if my hardware was not check before. I also think a small core XY like mine can handle high acceleration/jerk like i was pleased to use before this problem. As Sniffle write, dropping down the acc/jerk to a prusa architecture level for a core XY with light carriage and smooth linear rail doesn't sound right mainly when it worked well previously for the same model.I don't want to bother you with this, i'm testing and trying to give you feedback.
I'm trying your setting now and will see if they solve this.
This is my config.g :; Machine configuration
M569 P0 S1 ; Drive 0 goes forwards (change to S0 to reverse it)
M569 P1 S0 ; Drive 1 goes forwards
M569 P2 S1 ; Drive 2 goes forwards
M569 P3 S1 ; Drive 3 goes forwards
M569 P4 S0 ; Drive 4 goes forwards
; If you use an endstop switch for Z homing, change Z0 to Z1 in the following line, and see also M558 command later in this file
M574 X1 Y1 Z1 S0 ; set endstop configuration (X and Y and endstops only, at low end, active high)
M667 S1 ; set CoreXY mode
M350 X16 Y16 Z16 E16 I111 ; Set 16x microstepping with interpolation
M92 X160 Y160 Z800 ; Set axis steps/mm
M92 E394:394 ; Set extruder steps/mm
M906 X1500 Y1500 Z1200 E1500 ; Set motor currents (mA)
M201 X4500 Y4500 Z500 E8000 ; Accelerations (mm/s^2)
M203 X45000 Y45000 Z1500 E25000 ; Maximum speeds (mm/min)
M566 X1500 Y1500 Z100 E2500 ; Maximum jerk speeds mm/minute
M208 X170 Y200 Z270 ; set axis maxima (adjust to suit your machine)
M208 X-8 Y0 Z-0.5 S1 ; set axis minima (adjust to make X=0 and Y=0 the edges of the bed)
G21 ; Work in millimetres
G90 ; Send absolute coordinates…
M83 ; ...but relative extruder moves
;M581 E0 S1 T2My motors are :
Nema17 size 42mm
Body Length 48mm
Rated Current: 1.68A
Holding Torque: 0.44N.m
400 steps per revolution
Rated resistance phase : 1.65
Phase inductance 4.3mH
insulation resistance 100Mohm
From robotdigg
They are powered in 24V and from M122 : Supply voltage: min 23.9, current 24.0, max 24.5, under voltage events: 0, over voltage events: 0What does the max speed while printing ? it seem to be use when a travel is not setup in a pause macro, it's happen to me with this value and no step or shifted problem has been result with this value.
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Thanks for the info. One other question: what travel speed do you have configured in your slicer?
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300mm/s for travel speed
145 mm/s for infill and shell 50% for outline -
I had the same issues with the 1.15 and higher. Yesterday even tried the 1.16beta5 but still this problem exists.
Will keep mine on 1.14 as it runs very smooth on this version.DC42 if you need more development info please let me know. Can make a report or something for you if you would like.
It's not my first delta (build around 250 delta's now… ) so maybe i can help a bit. -
Strange enough i uploaded on my testprinter 1.16beta10 and first test was ok. Not the speeds that i used to but ok in printing. Anything changed on stepper/motion part?
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Nothing changed in the stepper motor driver code in either 1.15 or 1.16. There was a bug fix to pressure advance in 1.15.
Can you confirm that you are using the on-board stepper drivers?
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IMO, layer shifting is always due to some mechanical problem - especially when it's as bad as the pics in the first post. Have you checked that the pulleys are securely fixed to the motor shaft?
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Those shifting in first post was not due to mechanical, otherwise it will not append strictly at the same height…
I've made few test without stepper interpolation and it seem to work better, i didn't have shifting since removing it. But this result have to be validate with real comparaison test...
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It can be mechanical i.e. a print bed not properly secured so that it moves laterally my mini kossel does this as the bed mounts I made for FSR's are not clamps so the bed can shift it its not properly inserted, or electrical i.e. a motor skipping steps due to insufficient current, or being asked to move faster than it is able (i.e. insufficient current).
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I am using the onboard drivers in this model. Nothing hardware related because changing the board will make it print flawless.
Sadly i was using pressure advance and this last print i removed it.But i don't want to hijack this thread. So we keep it to the shifting of the topic owner.
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@Djdemon i monitored the print and there was not mechanical, nothing move like bed shifting. It's more like the board forget few step
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@cubexupgrade:
@Djdemon i monitored the print and there was not mechanical, nothing move like bed shifting. It's more like the board forget few step
But it only affects one motor, hence the 45 degree angle of shift (corexy). Loose wire? Bad motor? Can you swap the XY motors and see if the shift then happens in the other direction? Looking at all the stringing at the bottom of the model, are you sure the nozzle didn't catch on a lump of plastic which either shifted something mechanically, caused the pulley to slip, or caused the motor to skip a few steps?
@DC42, does interpolation affect motor torque? Just wondering if there is a mechanical resistance to movement, might a motor be more likely to skip steps with interpolation enabled.
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Interpolation will have only a tiny effect on motor torque. Maximum torque is produced when the motor is nearly 2 full steps behind the commanded position. A few 1/256 steps either way isn't going to make much difference.
@cubexupgrade, are the two motors of the same type and definitely running at the same current? If you are using M584 to remap drivers, you should specify the mappings for all axes and extruders, and set the motor currents afterwards.
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@dc42 motors and current are the same. I haven't use motor mapping for this printer.
Since i deactivate interpolation i use pressure advance function without problem even with high accl/jerk. Maybe it's just hasard.
I do not push test because i've to print lot of stuff for works. -
Hi all
Was this issue ever resolved ?? Im having similar problems ( 1,5 & 1.16)
Prusa i3 steel Cartesian . Works fine with a ramps 1.4 with TMC 2100'sDoesn't always happen.
Doesn't happen at the same height
When it occurs its X and Y at the same time but not by the same amount.
Checked all the usual suspects but as yet no real culprit to be found
All help / input appreciatted
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scientifically(one test print at a time), try reducing or eliminating your pressure advance first, then lowering your accel and jerk settings to what would be a more "normal(i3)" level.
I eliminated my layer shifting by greatly reducing my accel and jerk settings and there has been mention of potential issues with to many steps being generated on circular moves from pressure advance that can cause steps to be lost, though i think this was also squashed or its impact reduced.
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Thanks ill certainly try that
Whats wierd is in the 2 months or so that ive been using the Duet Wifi its worked fantastically well on large and small prints alike . Just this past week or so ive had problems.
I'm not 100% convinced it the Duet Wifi but with all the usual suspects checked and double checked, i'm at a bit of a loss as to whats going on.
The only thing that has actually changed that i know of is ive upgraded to Simplfy 3D 3.1.1 but i cant really see how that would create this issue.
Maybe i should try another slicer to be sure.
