Bed- and headposition after print

U1 Toolchanger U1 Troubleshooting guides
1

Hello,

i got my U1 aswell and had a few things that bugged me, coming form a Bambu P1S.

One is the ease to use and comfort of the AMS, which would in my opinion be a really nice upgrade to the spool holders. I will try to implement an alternative soon with my setup.

The other thing i noticed right after the first flow calibration squares was, that the printer was so slow when doing small prints after another. Every time the bed lowered nearly to the bottom. So before the next print the bed needs to home and that takes quite a while in slow speed for homing. I wanted to change that like my prior printers did that, just lowering a bit when the print is finished.

Its quite a long time since i had to dig into the printer configs, so it took a while until i had a solution. But with lowering just a bit, you have the printhead a bit in the way to take the printplate out, so the park position for the head needs to be in the back.

For anyone who is annoyed by that aswell here is what i changed. Or someone has a better solution i didnt see so far.

For it to work, you need to use the advanced mode of the printer. Then in the fluidd.cfg you need to change the following lines of the PRINT_END macro

{% if "xy" in printer.toolhead.homed_axes %}
        PARK_EXTRUDER
        G90
        G0 X5 Y5 F3000

TO

{% if "xy" in printer.toolhead.homed_axes %}
        PARK_EXTRUDER
        G90
        G0 X5 Y275 F3000 # parks head in the back

AND

{% if "z" in printer.toolhead.homed_axes %}
        {% if current_pos.z < 200 %}
            G90
            G0 Z200 F2000

TO

{% if "z" in printer.toolhead.homed_axes %}
        {% if current_pos.z < 200 %}
            G91 # relative coordinates
            G0 Z10 F2000 # lowers bed 10mm

Then save and restart klipper.

Maybe its helpful for some as it works for me.

Please be aware of the fact, that its not what SM implemented (maybe for a reason) and i m no expert. So use at your own risk.

1 Like
2

If you have a large print won’t the bed try and raise to Z10 and smash your print when its done?

3

As the G91 command accounts for relative movements instead of absolute coordinates, the G0 Z10 command means to lower the bed 10mm whereever it sits at this moment.

So the bed is at 3mm, it lowers to 13mm,
the bed is at 200mm, it lowers to 210mm

It works like it should, but i m not that satisfied yet, because on small prints, the 10mm aint enought to comfortably reach in and detach the bed.
So i will try to implement that it lowers a larger amount when it is a small print, and just a little when its a large print.
I guess that is what the printer.toolhead.homed_axes % is for.

4

I was a bit distracted by the % in the codes and couldnt figure out what the 200 meant in that context. Just stupid me… its not a percentage, but part of the code.

So im happy with the following configuration:

{% if "z" in printer.toolhead.homed_axes %}
        {% if current_pos.z < 45 %}
            G90
            G0 Z45 F2000
        {% elif current_pos.z < 265 %}
            G91
            G0 Z3 F2000
        {% endif %}

It moves the bed to 45mm if the print is up to 45mm
If the print is larger, it lowers the bed by 3mm

I also configured CANCEL_PRINT the same.

1 Like
5

Is this something you could add to the End g-code in Orca or will the firmware over ride it?

6

in the end gcode there are only 2 macros: print_end and timelapse_stop
if you are sure, that there is nothing important in it, you can erase the print_end macro and just use normal g-code.