Auto bed leveling issues February 10, 2019 03:01PM |
Registered: 5 years ago Posts: 29 |
Re: Auto bed leveling issues February 10, 2019 06:50PM |
Registered: 6 years ago Posts: 1,863 |
Re: Auto bed leveling issues February 11, 2019 01:31AM |
Registered: 6 years ago Posts: 1,007 |
Re: Auto bed leveling issues February 11, 2019 05:10PM |
Registered: 9 years ago Posts: 752 |
Re: Auto bed leveling issues February 12, 2019 05:55AM |
Registered: 5 years ago Posts: 29 |
Quote
imqqmi
A warp deviation of more than 0.15mm will make it really hard to get a first layer across the bed, even at a first layer height of 0.3mm regardless if you use auto bed levelling. I'd try to first level the bed as best as you can. Also make sure the bed can expand in the x and y plane. If it's fixed it will warp. Also make sure consecutive probing values are consistent.
I've used shims to level my bed, and I don't use auto bed levelling anymore. I had to bend the bed a little using a glue clamp. It took care of most of the warp. Make sure the bed support structure can handle the clamping force though. Mine is made up from 2040 extrusions, so they can handle the abuse. I used a dial indicator on the printhead to find out how level it was at 3 points in a triangle. After a few attempts it was level enough to start a print at 0.3mm first layer height across the bed.
Re: Auto bed leveling issues February 12, 2019 09:03AM |
Registered: 6 years ago Posts: 1,863 |
G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
;M106 S127 ;set Fan half speed
M107 ;start with the fan off
G28 X0 Y0 ;move X/Y to min endstops
G28 Z0 ;move Z to min endstops
G1 Z15.0 F{travel_speed} ;move the platform down 15mm
;Put printing message on LCD screen
;M117 My Print...
G28 X0 Y0
G1 E4.0 ;prime extruder
G92 E0 ;reset extruder length
M420 S1 ; Bed Leveling On
M220 S32.000000 ; Set Startup Start Print Speed.
;M420 V1 ; Print the leveling grid
Re: Auto bed leveling issues February 12, 2019 09:59AM |
Registered: 9 years ago Posts: 752 |
Re: Auto bed leveling issues February 13, 2019 09:43AM |
Registered: 6 years ago Posts: 1,863 |
Quote
imqqmi
The auto bed leveling is only trying to level the bed by rotation, it's not trying to compensate for unevenness. So a warped bed will remain warped but it's treated as square to the axes on average.
Re: Auto bed leveling issues February 13, 2019 02:21PM |
Registered: 5 years ago Posts: 29 |
Quote
Roberts_Clif
I should also note When Using Marlin Bed Leveling,
When Starting a print G28 will disable the bed leveling data unless you have Bed Leveling Command in the Slicers Startup G-Code.
Using Bi-Linear Bed Leveling you can Save the Bi-linear Bed Leveling Data and Recall this data By Adding a " M420 S1" to the End of Slicers Startup G-Code.
This is a My Startup G-Code
G21 ;metric values G90 ;absolute positioning M82 ;set extruder to absolute mode ;M106 S127 ;set Fan half speed M107 ;start with the fan off G28 X0 Y0 ;move X/Y to min endstops G28 Z0 ;move Z to min endstops G1 Z15.0 F{travel_speed} ;move the platform down 15mm ;Put printing message on LCD screen ;M117 My Print... G28 X0 Y0 G1 E4.0 ;prime extruder G92 E0 ;reset extruder length M420 S1 ; Bed Leveling On M220 S32.000000 ; Set Startup Start Print Speed. ;M420 V1 ; Print the leveling grid
You can Save the Data simply by selecting the Save Settings on The LCD Display
OR
M500: Save Settings - Marlin Firmware
M420: Enable/Disable Bed Leveling and/or set the Z fade height.
S[bool] Turns leveling on or off
Z[height] Sets the Z fade height (0 or none to disable)
V[bool] Verbose - Print the leveling grid
This Allows you to view bed leveling data.
M420 V
// M851 give a range for adjusting the Z probe offset
#define Z_PROBE_OFFSET_RANGE_MIN -20
#define Z_PROBE_OFFSET_RANGE_MAX 20
Set with M851 Z-5.2 or #define Z_PROBE_OFFSET_FROM_EXTRUDER -5.2.
Re: Auto bed leveling issues February 14, 2019 06:34AM |
Registered: 5 years ago Posts: 29 |
Could you post a picture of you glue clamp thing? I have a hard time understanding what you mean.Quote
imqqmi
A warp deviation of more than 0.15mm will make it really hard to get a first layer across the bed, even at a first layer height of 0.3mm regardless if you use auto bed levelling. I'd try to first level the bed as best as you can. Also make sure the bed can expand in the x and y plane. If it's fixed it will warp. Also make sure consecutive probing values are consistent.
I've used shims to level my bed, and I don't use auto bed levelling anymore. I had to bend the bed a little using a glue clamp. It took care of most of the warp. Make sure the bed support structure can handle the clamping force though. Mine is made up from 2040 extrusions, so they can handle the abuse. I used a dial indicator on the printhead to find out how level it was at 3 points in a triangle. After a few attempts it was level enough to start a print at 0.3mm first layer height across the bed.
Re: Auto bed leveling issues February 14, 2019 10:51AM |
Registered: 6 years ago Posts: 1,863 |
Quote
chrstrvs
So you have done a G29 and saved the values once, and these values are used with M420 instead of doing a G29 every time you print?
Re: Auto bed leveling issues February 14, 2019 01:58PM |
Registered: 5 years ago Posts: 29 |
Quote
Roberts_Clif
Quote
chrstrvs
So you have done a G29 and saved the values once, and these values are used with M420 instead of doing a G29 every time you print?
This is correct! Sometimes I only have to level once a month. Unless the bed tension springs screws work themselves loose do to vibrations.
Should add a rubber washer to help stop the Bed tension screws from turning -- Maybe help it from not turning.
Re: Auto bed leveling issues February 15, 2019 03:35PM |
Registered: 9 years ago Posts: 752 |
Re: Auto bed leveling issues February 15, 2019 04:56PM |
Registered: 6 years ago Posts: 1,863 |
Re: Auto bed leveling issues February 16, 2019 06:01PM |
Registered: 9 years ago Posts: 752 |
Re: Auto bed leveling issues February 18, 2019 02:38PM |
Registered: 5 years ago Posts: 29 |
Quote
imqqmi
It's just a c clamp. I measured using a dial indicator and found that it was warped on one side. I used two 2040 extrusions as bed support so it was strong enough to clamp on that and the side/middle of the bed. The rise was clamped down and bowed against the rise. Make sure not to over do it. After (removing the clamp) that the dial indicator gave better measurements.
A clamp like this:
I hope it's a little clearer now.