Having problems with Anycubic Kossel Linear Plus calibration

SnakeSP

@veti Yes, Marlin has 267, i took 271.5 after one of the calibration attempts. Will change to 267 and try again (actial measurements show 266.5, but not sure that those are really accurate as i was using just a metal ruler).

SnakeSP

@jay_s_uk No, steps are correct, i'm using 16 teeth pulleys now, not 20 teeth as in the original build.
Tried bed compensation - did not help.

SnakeSP

Set L=267, recalibrated with S6:

6:22:32 PMM666
Endstop adjustments X-0.86 Y0.95 Z-0.09, tilt X0.00% Y0.00%
6:22:27 PMM665
Diagonal 267.000, delta radius 133.934, homed height 287.589, bed radius 115.0, X 0.517°, Y -0.986°, Z 0.000°
6:22:11 PMG32
Calibrated 6 factors using 16 points, deviation before 0.041 after 0.041

Checked with S-1:
6:28:52 PMG32
G32 bed probe heights: 0.061 0.048 -0.070 -0.012 0.047 0.035 -0.052 -0.038 0.061 0.031 -0.060 -0.030 0.000 0.011 0.019 -0.029, mean 0.001, deviation from mean 0.043

Checked that the nozzle goes to correct position: lowered nozzele to Z=0 and was hardly able to put paper between nozzle and bed (just as back then when i was on Marlin), so Z=0 is about 0.08 mm above the bed at center. Tried moving nozzle at Z=0 - height is about the same.

Commented M208 Z0 S1 in the config.goes

Tried printing PLA at bed 50C and hotend at 190C. Layer = 0.2, no offsets applied. Printing goes mid air.
Tried using baby stepping. No changes till -0.2. With baby stepping = -0.2 plastic hardly sticks to bed but is moved away by the nozzle when it goes to the next line.
Baby stepping = -0.22 made plastc smash into the bed.

I really do not understand what's wrong...

Veti

@snakesp said in Having problems with Anycubic Kossel Linear Plus calibration:

really do not understand what's wrong...

while printing do a M122 and show us the output. just to make sure that no mesh bed leveling is active.

SnakeSP

@veti said in Having problems with Anycubic Kossel Linear Plus calibration:
7:03:57 PMM122
=== Diagnostics ===
RepRapFirmware for Duet 2 WiFi/Ethernet version 2.0(RTOS) running on Duet WiFi 1.02 or later
Board ID: 08DGM-9T6BU-FG3SW-6J1FG-3SS6L-KBTHH
Used output buffers: 3 of 20 (15 max)
=== RTOS ===
Static ram: 28380
Dynamic ram: 95920 of which 16 recycled
Exception stack ram used: 372
Never used ram: 6384
Task NETWORK ready, free stack 396
Task HEAT blocked, free stack 1256
Task MAIN running, free stack 3624
=== Platform ===
Last reset 00:18:40 ago, cause: software
Last software reset at 2019-09-01 18:45, reason: User, spinning module GCodes, available RAM 6384 bytes (slot 1)
Software reset code 0x0003 HFSR 0x00000000, CFSR 0x00000000, ICSR 0x0041f000, BFAR 0xe000ed38, SP 0xffffffff
Error status: 0
Free file entries: 9
SD card 0 detected, interface speed: 20.0MBytes/sec
SD card longest block write time: 0.0ms
MCU temperature: min 56.2, current 56.4, max 56.6
Supply voltage: min 23.2, current 23.9, max 24.3, under voltage events: 0, over voltage events: 0
Driver 0: ok, SG min/max not available
Driver 1: ok, SG min/max not available
Driver 2: ok, SG min/max 75/194
Driver 3: ok, SG min/max not available
Driver 4: standstill, SG min/max not available
Date/time: 2019-09-01 19:03:55
Slowest loop: 174.92ms; fastest: 0.08ms
=== Move ===
Hiccups: 0, StepErrors: 0, LaErrors: 0, FreeDm: 228, MinFreeDm 213, MaxWait: 0ms, Underruns: 0, 0
Scheduled moves: 56, completed moves: 53
Bed compensation in use: none
Bed probe heights: 0.000 0.000 0.000 0.000 0.000
=== Heat ===
Bed heaters = 0 -1 -1 -1, chamberHeaters = -1 -1
Heater 0 is on, I-accum = 0.1
Heater 1 is on, I-accum = 0.2
=== GCodes ===
Segments left: 1
Stack records: 2 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 X9.475 Y-40.525 F900" 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: 3.74ms; fastest: 0.01ms
Responder states: HTTP(0) HTTP(0) HTTP(0) HTTP(0) FTP(0) Telnet(0) Telnet(0)
HTTP sessions: 1 of 8

WiFi -
Network state is running
WiFi module is connected to access point
Failed messages: pending 338, notready 0, noresp 0
WiFi firmware version 1.21
WiFi MAC address 4c:11:ae:02:e3:cf
WiFi Vcc 3.33, reset reason Turned on by main processor
WiFi flash size 4194304, free heap 16200
WiFi IP address 192.168.1.37
WiFi signal strength -70dBm, reconnections 0, sleep mode modem
Socket states: 0 0 0 0 0 0 0 0
=== Expansion ===

M122

Veti

@snakesp said in Having problems with Anycubic Kossel Linear Plus calibration:

RepRapFirmware for Duet 2 WiFi/Ethernet version 2.0(RTOS) running on Duet WiFi 1.02 or later

you are using a very old version of the firmware. just to rule out any problems there update to 2.04RC1

but the problems comes down to this? with marlin pla sticks on the ultrabase. with duet it does not?

SnakeSP

@veti Simply put, yes, with Marlin prints were ok, with Duet plastic does not stick (not only PLA, PETG also).
But i'm almost sure this is due to i'm doing something wrong.
Will try updating to 2.04 RC1 today and recalibrate.
Also it may occur that thermistors are configured incorrectly (hotend thermistor is changed from original one, but the bed is the same except changing it to 24V).
Possibly bed or hotend or both produce lower temperature than expected, but not sure how test this. But on the other hand PLA should stick even to cold bed.

Veti

@snakesp said in Having problems with Anycubic Kossel Linear Plus calibration:

lowered nozzele to Z=0 and was hardly able to put paper between nozzle and bed

this means that your offset is wrong btw. if there is space between the nozzle and bed for paper, then z=0 is not z=0 rather something like z=0.1+movement space.

Veti

what thermistors have you configured in marlin?

SnakeSP

@veti
Current Z probe offset is Z15.791, do you mean i should change it to 15.891 ?
It was
5 : 100K thermistor - ATC Semitec 104GT-2/104NT-4-R025H42G (Used in ParCan & J-Head) (4.7k pullup)
in Marlin, but that was original Anycubic thermistor. Same one for the bed.

Veti

that is significantly different.

semitec is B4725 C7.060000e-8

SnakeSP

@veti Yes, you are right, looks like i really need to change B from 3950 to 4725 at least for the bed thermistor, but what about the hotend thermistor? It is different from the bed one. And should i use С parameter?
And about Z offset for the probe: should i change it to 15.891?

Veti

@snakesp said in Having problems with Anycubic Kossel Linear Plus calibration:

And should i use С parameter?

yes without that the B parameter is wrong.

for the offset. what i do is do a first layer print. if i need to adjust it with microstepping to get a good first layer i update the offset with the microstepping used.

SnakeSP

~~The firmware upgrade guide tells to update not only the firmware itself, but DuetWiFiServer and DuetWebControl.~~
~~WHATS_NEW.md for 2.04RC1 says, that compatible files are:~~
~~DuetWiFiServer 1.23~~
~~DuetWebControl 1.22.6 or 2.0.0-RC6 or 2.0.0-RC7~~

~~But i cannot find those files. Can you point me where to get those?~~
And also a question: what is an appropriate order to upgrade firmware? Upload all 3 files to /sys through Settings-General-Upload files declining update offers and run M997 S0:1:2 after that, correct? Will it preserve my network settings or i'll need to connect using usb and terminal to restore those?
Nevermind. Found those:
WiFiServer in 2.0.3 release
WebControl

SnakeSP

Results so far:
updated firmware
changed bed thermistor to B4725 C7.060000e-8
recalibrated with 15.881 (recalibrated Z probe, at Z=0 no paper can be placed under the nozzle)
tried printing

190C 50C babystep=0 - no sticking to bed at all
190C 50C babystep=-0.5 - partially sticking, corners not sticking
190C 50C babystep=-0.8 - smashed into the bed
200C 60C babystep=-0.5 - better sticking, some corners not sticking
200C 60C babystep=-0.6 - same
But when trying to print at center of the bed - no sticking until babystep=-0.12 at all

Looks like the calibration is still not consistent, although with S-1 it reports height deviations less than 0.07:
G32
G32 bed probe heights: 0.056 0.037 -0.068 -0.010 0.041 0.026 -0.060 -0.038 0.058 0.032 -0.059 -0.034 -0.000 0.021 0.029 -0.031, mean -0.000, deviation from mean 0.042

Thoughts:
either calibration is still incorrect or temperature is still incorrect.

Veti

can you check with 7 factor what the rod length is calculated to be.
and maybe try 8 factor.
https://duet3d.dozuki.com/Wiki/Calibrating_a_delta_printer

SnakeSP

@veti Will do a bit later.
For now i've got some more interesting findings. Near the morning i've got crazy and ended up with Hotend at 235C and bed at 80C. And suddenly PLA sticked to bed even without any babystep. The print quality was bad, but plastic sticks. So it looks like more likely the problem is not with calibration itself, but with thermistors showing fake temperatures.
Hotend thermistor was set to B3950 (as on Biqu site where i've bought it).
Bed was B4267 as in Marlin.
I took a multimeter and tried to measure the temperature with it. For bed it was about 5С under on multimeter till 60C on Duet and about 8-9C under from 60С till 85C on Duet.
But with hotend this is a different story. I tried to put a thermocouple from multimeter to the heating cube near the thermistor shaft and the results on multimeter were absurdly low:
173C when it was 235C on Duet.
So the problem for now is: how to make printer thermistors show actual temperature (or at least close to real)?

Veti

@snakesp said in Having problems with Anycubic Kossel Linear Plus calibration:

Hotend thermistor was set to B3950 (as on Biqu site where i've bought it).

the chinese B3950 are a bit of a pain. that beta is only accurate for the range of 25-50C.
There seem to be different variation of these that behave differently at higher temperature ranges.
I had some trouble with those and in the end got a pt1000.

SnakeSP

@veti Don't have PT1000 right now, but looks like i'll end with it.
But i need to make prints by the end of this week and won't be able to get PT1000 by then.

As for the current thermistor, i've managed to get almost acceptable results up to 100C so far by using boiling water and measuring thermistor resistance (B3988). Now thinking how to get resistance at 200-250C. Possibly can steal curling iron from my wife and use it to get needed temperature

SnakeSP

@snakesp No luck, curling iron won't give steady temperature...
Yet looks like it is possible to print using temperature approximations with current beta: +5-10C on hotend and +7C on bed. Not best quality, but sufficient so far. Will get PT1000 or PT100 after a while.

Now back to calibration. The outcoming print does not have accurate dimensions. Z is less for 0,05, which is good enough.
But X and Y are off +0.3 - +0.4 mm. Which is not good. Changing rod length should resolve this i assume, but the question is: should i use autocalibration with S7 or just leave the calibrations as they are and only change the rod length in config-override.g?