Bed Levelling Using 3 Independent Z Motors

[Phaedrux]

How do you plan to do bed leveling without a Z probe?

Even the manual leveling needs a probe to know the distance to the bed to be able to tell you how much to adjust the bed leveling screws.

Using a manual Z probe option could be done, but would be pretty tedious.

[SANJR]

@Phaedrux Thanks for the feedback

It is planned for manual Z probe at the starting and latter after stabilization, a Z probe is planned to install.

If a manual Z Probe is option is to be used the G31 Command is to be pasted to know the trigger height. But i am not able to find the same.

What could be the reason for it and how to correct it?

[Phaedrux]

If you're using the manual probe mode (M558 P0) then your G31 offset would be X0 Y0 Z0 because you are using the nozzle tip to set the position. So add G31 X0 Y0 Z0 to your config.g after the M558 command.

[SANJR]

@Phaedrux Thanks for the reply

Request to check the Z Probe section of Config.g file for G31 COMMAND

[Phaedrux]

Yes that looks ok. Have you sent a G30 command to test out how it will work?

[SANJR]

@Phaedrux Thanks

I would start testing the motors movement very soon, after that i would test the G30 as well.

[SANJR]

Hi,

I have started testing the bed leveling; the bed.g file is pasted below. It was thought that there would be three probe points. however after the G28, home all COMMAND the program not working. The config.g file to check the M671 and the drive height is pasted below for your perusal

bed.g
M561 ; clear any bed transform
G28 ; home
G90 ; set to absolute positioning
G30 P0 X50 Y300 Z-0.02 ; probe near a leadscrew
G30 P1 X400 Y450 Z-0.02 ; probe near a leadscrew
G30 P2 X545 Y300 Z-0.02 ; probe near a leadscrew
M400 ; wait for current moves to finish

;Drives
M671 X50:400:545 Y300:450:300 S15.0 ; leadscrews at Front left, Rear middle and Front right

; Z-Probe
M558 P0 H5 F120 T6000 ; disable Z probe but set dive height, probe speed and travel speed
G31 X0 Y0 Z0 ; set or report current probe status
M557 X0:550 Y0:460 S100 ; define mesh grid

[droftarts]

@SANJR said in Bed Levelling Using 3 Independent Z Motors:

G30 P2 X545 Y300 Z-0.02 ; probe near a leadscrew

You need an S3 parameter on the last probe point. See the example 'for 3 motor' here: https://docs.duet3d.com/en/User_manual/Connecting_hardware/Z_probe_auto_levelling#examples

Ian

[droftarts]

@SANJR Also, your leadscrew pivot points are within the bed area and seem a bid odd to me. Are you sure they are correct? What is the bed size (M208)?

M671 X50:400:545 Y300:450:300 S15.0 ; leadscrews at Front left, Rear middle and Front right

Again, read the documentation on this page: https://docs.duet3d.com/en/User_manual/Connecting_hardware/Z_probe_auto_levelling

Ian

[SANJR]

@droftarts

The Axis Limits I have set as the following
M208 X0 Y0 Z0 S1 ; set axis minima
M208 X550 Y460 Z300 S0 ; set axis maxima

[SANJR]

@droftarts Thanks i have added the S3 parameter at the last and its working good. Now after completing the bed probe mesh i.e., G29 the height map in not able to be viewed, but i am able to see the value is the system directory heightmap.csv like an tabular column. How can i make these values to be represented as a graph?

[droftarts]

@SANJR Do you have the 'Height Map' Plugin enabled in DWC? If not, go to Settings > Plugins and 'Start' it.

Ian

[SANJR]

Got It. Thank you very much