Can't seem to set where the bed should be when print starts

TimV 0

G28 ;Home

G92 E0 ;Reset Extruder
G1 Z2.0 F3000 ;Move Z Axis up
G1 X10.1 Y20 Z0.28 F5000.0 ;Move to start position
G1 X10.1 Y200.0 Z0.28 F1500.0 E15 ;Draw the first line
G1 X10.4 Y200.0 Z0.28 F5000.0 ;Move to side a little
G1 X10.4 Y20 Z0.28 F1500.0 E30 ;Draw the second line
G92 E0 ;Reset Extruder
G1 Z2.0 F3000 ;Move Z Axis up

Thanks for spotting the S1

TimV 0

@TimV-0 Reset the 2nd S1 to S0
Z does not stop when the BL Touch touches the bed. It keeps going.

Phaedrux

Have a run through this: https://docs.duet3d.com/en/User_manual/Connecting_hardware/Z_probe_testing

TimV 0

@Phaedrux Thanks - will do. There are too many documents on this subject imho

TimV 0

@TimV-0 When I fixed the last problem with the double S1's I didn't realize that the probe was trying to trigger while off the bed on the minimum side. I adjusted the x position to 35 and now the probe is triggering properly.

It triggers repeatably at 2.5 mm on the probe and then lowers to exactly 7.5 according to the tool position display.

Perhaps I should try a test print?

TimV 0

@TimV-0 Finished the last paragraph in the document and the probe is triggering reliably. Tool position is consistent at 2.875

TimV 0

@TimV-0 Sorry, I bet you wish I would read the whole document before applying one sentence and reporting back. I'll try

TimV 0

@TimV-0
I’m still fighting with this. I figured out that my bed kept climbing because the bltouch was off the left side of the plate

I have gone through the document several times and I end up in the same place.

I have brought up the bed and levelled it with a piece of paper until it is consistently perfect. I set the z height to zero, drop the bed by 10mm, issue the g s-1 command and I end up with 2.5mm. I’ve put that in my config.g file, and when I start a print, the filament is falling in thin air to the bed.

I’ve tried to adjust z by microstepping, but since the print has started, I can’t adjust z through DWC, since it needs to be homed again.

Phaedrux

Can you share a small sliced gcode file so we can see what your slicer is doing at the start of a print? Please also post your config.g and homing files if they have changed.

TimV 0

Phaedrux

What does your heightmap look like?

When are you running bed.g?

When do you load the heightmap?

Maybe you aren't using mesh compensation at all.

After doing a homeall, can you jog the nozzle to touch the bed? Does the Z axis position show 0 when it's touching the bed?

If you tell the Z axis to move 10mm, does it actually move 10mm if you measure it? In otherwords, are you sure your Z axis steps per mm are correct? Or is the Z axis moving smoothly without missed steps or binding?

I don't see anything obvious from your gcode files. Perhaps you could record a video showing from power on, to starting a print.

TimV 0

@Phaedrux
Once more for good luck.
From the Test and Calibrate Document
HomeX Ok
HomeY Ok
HomeZ Ok After G30 is run, bed raises until bltouch triggers. Bed stops raising at 2.73mm from nozzle

Calibrate the Z probe trigger height
Issue M561 - done
Center nozzle at center of bed - done
Z is still reporting height = 2.73mm
Raise the bed to remove the 2.73mm
Bed not trapping paper
Issue M564 S0
Nozzle contacts paper at -0.4mm
Nozzle stops paper at -0.45mm
Issue G92 S0 - Confirm bed height indicates 0.00
Lowered Bed by 5mm
Measured distance to confirm 5mm
G30 S-1 stopped at 2.73
G31 P500 X-45 Y0 Z2.73 set in config.g
edited G31 in config.g.bak

Reset the duet 2 board.

Position indicator says Z 0.00

That is not true. after the board reset, the nozzle is 10mm above the bed

HomeX -- ok
HomeY -- ok
HomeZ -- ok

Tool position reports Z at 2.73mm

I don't want to do anything else on my own until I understand for sure what is happening.
Is this not the result of what I set in the G31 command in config.g?

Ok, I am really confused now. I started a print job and it is printing perfectly. I have a good, even first layer.

TimV 0

@TimV-0 Sorry, it is not perfect. I think I need to run the autobed levelling to set up the heightmap properly. I just hope it doesn't undo what I have done

Phaedrux

@TimV-0 That all sounds accurate. After a power cycle the position is lost, so having to rehome is normal.

The position seems to be reporting correctly after homing.

You are using G31 and the procedure to find the trigger height value correctly.

Home the printer and then send G29 to create a mesh. (or G32, since your bed.g just contains G29)

Seeing what the heightmap looks like would be a good next step.

TimV 0

@Phaedrux Thanks for all of your help and for sticking with me.

I will do the auto bed levelling next. I did look at the height map that I had and it looks terrible. I am currently printing a case for the duet 2 board to make it a little safer and hopefully protect the actual wiring. I know I should have done the auto bed levelling first. |I had some quality issues and some print lifting. I should have really cleaned the print surface first. Just because it's brand new doesn't mean it is ready to go. I will also need to go over the extruder setup as I can see from the print that it is no set properly.

I did add a dual gear extruder, but I am thinking that maybe I should stack it on the carriage and get rid of the long bowden tube. Any thoughts or cautions I should know about?

Phaedrux

@TimV-0 said in Can't seem to set where the bed should be when print starts:

Any thoughts or cautions I should know about?

Just follow the principle of one thing at a time.

TimV 0

@Phaedrux
Always good solid advice. Most of my issues with why I wrote in for help are related to no knowing which problem was creating which challenge.

TimV 0

@TimV-0 Hi: I sent out the G29 last night to generate a heightmap.
It sampled lots of spots on the bed and I got no feedback.

I tried printing today and I have a small forest of PLA that I wasn't expecting.

I clicked on the heightmap and it is empty. I'm sure the bed is not perfectly flat.

Is there somewhere I should have saved it when it finished? I think I sent an M500 because I thought I should.

Phaedrux

It kind of sounds like you might have your DWC version out of date.

Upload this zip file to the system tab in DWC. That should get everything up to date.

https://github.com/Duet3D/RepRapFirmware/releases/download/3.4.4/Duet2and3Firmware-3.4.4.zip

Also check that the heightmap plugin is enabled and maybe clear your browser cache.

TimV 0

@Phaedrux
Thanks for the file. I can't be certain for all of the files, but the .zip file is the one that I have loaded.

The heightmap tab was a big orange icon that said stop in the plugins. All the other plugins said start. Is this backwards or was it the only plug in running and I just shut it off? I clicked it again and it still shows the big green icon that says start?

I have lost the heightmap icon on the main DWC which is what I clicked to see it in the first place. Not there any more.

I'll just pretend I know what I am doing for now as I don't really want to restart the print

The screens don\t seem to display what I would expect...