Posts made by SnakeSP

@Samuel235 I'm facing the similar thing.
My extruder is BMG with 3:1 ratio. Bowden 55cm.
Printed test cube with jerk set to 600 and PA set to 0.2 through 1.0 - got very minor effect.
Previous experiments with python PA test script showed effect with PA set to 1.6-1.65 which made my extruder sing with forward-backward-forward rapid move on every line.
Now i think about trying to set jerk to 0 and raise acceleration, as the formula in doc is: actual_extrusion_speed = requested_extrusion_speed + (K * current_extruder_acceleration), which makes me think the jerk should be minimal while acceleration should be high.

@burtoogle Thanks!

@Phaedrux
Does not work for me
Cura 4.4.1, settings as you've specified - seam is generated in one of the corners no matter what coordinates i set.
Can you share a gcode of the cube (20x20x20) with a single perimeter with a seam in the center of one of the sides so i can modify it for my printer, please?

@Phaedrux
Yes, i tried that but Cura still places seam to the corner...

No matter what i try to set with "Choose start point..." the beginning of the line is always in the corner. Same for Cura. Does anyone know how to align Z seam to the center of the cube's side?

@Phaedrux
I tried the first one, with the python script.
Will try the second one, with the cube, but need to understand how to make Simplify3d to align seam at the center of the side, for now i can only align it to one of the corners.

One more thing still bothers me: i have not yet found the proper settings for BMG extruder (speed, acceleration, jerk) there are very different number said to be best in every topic i've read and there is nothing about it on Bondtech site. Can you point me where can i find such info please?

I have very strange results when trying to calibrate PA.
Here are the speed, acceleration and jerk settings:
M203 X15000.00 Y15000.00 Z15000.00 E6000.00
M201 X2000.00 Y2000.00 Z2000.00 E2000.00
M566 X1200.00 Y1200.00 Z1200.00 E1200.00
I'm using BMG cloned extruder (if matters) with bowden of 550 mm and ID 2 mm.
Used python script to print patterns with the following settings:
extrusion_width = 0.5 (nozzle is 0.4 actually, 0.5 is used in slicer as an extrusion width)
layer_height = 0.2
filament_diameter = 1.72 (measured with calipers)

travel_speed = 150
first_layer_speed = 15
slow_speed = 5
fast_speed = 70

I tried PA settings from 0.1 to 1.0 at first and there were no signs of PA working. Further experiments showed that noticable result is there only in range 1.5 to 1.9. But this looks insane... Or this is normal?
Also i noticed that the speed is limited to 63-65 mm/s (due to too low extruder settings possibly?).

@dc42 I'm a bit confused.
Let's say i'm measuring Z probe height initially at X0 Y0. I go through the steps 1-9 described in https://duet3d.dozuki.com/Wiki/Calibrating_a_delta_printer section "Measuring the trigger height". I read, let's say, 15.500 at that point. Repeating the steps 7-9 several times show that trigger height is consistent at X0 Y0. I put this value to config.g an do autocalibration.
After calibration i check the trigger height value at X0 Y0 and get consistent result 15.500.
But when i move, let's say, to X50 Y0 and do G30 S-1 i get 15.550. I repeat G30 S-1 several times at this point and always get 15.550. So this is consistent.
I thought that i should add this +0.05 value to G30 in the bed.g file for the corresponding point. Am i wrong?

@Danal On what plastic? I use PETG now and it is very prone to stringing. What extruder are you using? I'm on stock Anycubic one, which is not very accurate. Extruder modification is next thing to upgrade in my list after making magnetic arms.

@Veti That's interesting, but not in nearest future as it is rather complicated.

@infiniteloop Yes, lower temperature reduces stringing, but i'm already at 240 С for the first layer and 220 C for all higher layers. 220 C is the lowest temperature recommended by my filament manufacturer.
So looks the only 3 parameters i can play to reduce stringing are Retraction length, retraction speed and coast at end.

@infiniteloop
As for retraction speed - i tried low speeds (30-40 mm/s) and got way too much stringing. But will try to lower down for experiments.
Distance - yes, looks too much, will lower it.

@infiniteloop

@infiniteloop
Did just as you've suggested (Z probe height - 0.05) and surprisingly it did work (i have not changed heightmap.csv this time).
Print comes out with almost acceptable quality:
photo1
The only thing that bothers me is that defects at the start of each print:
photo2 photo3 photo4
it happens after retraction and moving to new coordinates, so i suspect this is due to incorrect retract settings in slicer.
For now i use (bowden tube 640 mm with ID 2 mm):
Retraction distance = 8.0 mm
Extra restart distance = 0.4 mm
Retraction vertical lift = 1 mm
Retraction speed = 100 mm/s
Coasting distance = 0,25 mm (was not able to make Pressure Advance work yet).
Z vertical speed = 40 mm/s, movement speed = 200 mm/s

@infiniteloop
Did that before and after autocalibration with new Z probe height (correct direction - subtracted 0.05, double-checked that) and creating new bed mesh ended with printing mid air... Which is strange.

@infiniteloop
Babystepping +0.05 works for the whole print. At least it did not make the other parts being printed worse.

@infiniteloop
The mesh is dense (305 points).
As for the delamination reasons - looks like the nozzle is a bit too low at that points. Babystepping +0.05 solved this, but this again is not permanent solution...

@infiniteloop
I have included G29 S1 into starting script in slicer, so the bed mesh is loaded (checked with M122).
The bed is deformed indeed, but not that much (+/- 0,16 should be compensated without major problems with bed mesh, i assume).
Probing speed is F120, should not be too fast.

Started from scratch (saved the working config to be sure).
Got bed heated to 70C, lowered nozzle to scratch the sheet of paper at center. Removed the paper and lowered nozzle -0,8 mm (measured paper thickness) so it was touching the bed (at least i assume).
Set that height to be Z=0.
Used G30 S-1 several times to determine the probe Z height. Saved it to config.g.
Rebooted printer and started S6 autocalibration. Got result about 0.048. Saved it with M500.
Measured Z offset at all points from bed.g with G30 S-1 and updated bed.g with H for each point.
Run S6 autocalibration again and got promising result:
Calibrated 6 factors using 16 points, deviation before 0.016 after 0.010. Saved with M500.
Subsequent calibrations gave results around 0.007.
So i tried running test print with 9 20x20 squares all over the bed with First layer height = 100 and First layer width = 100. Almost all came out fine except for one in the front and one at center.
After cooling, cleaning the bed and heating it back to 70C i used G30 to provide Z=0 datum and used G29 to create bed mesh. Results were rather good:
305 points probed, min error -0.091, max error 0.168, mean 0.034, deviation 0.043 (peak points at max radius).
Printing with bed mesh active and same slicer parameters gave exactly the same result as before.
So i tried to use First layer height = 150 and First layer width = 90 as i did before. Print came out almost the same as the one without bed mesh active. Again not sticking at center and front. I do not understand, as it looks like bed mesh is not working.
photo

@Veti
I had Z probe height at 15.585 when i got good first layer sticking with babystep +0.1 mm (higher from bed 0.1 mm) which gave me total nozzle height from bed 0.3 mm when printing first layer. Also extrusion was higher than normal.
When i tried to recalibrate i have set Z probe height to 15.485 mm, which is in my understanding moving nozzle 0.1 mm from the bed (lowering Z height is moving nozzle from the bed, increasing Z height moves the nozzle towards the bed), or maybe i'm wrong?