Bed crashes in lowest position

Bambu Lab X1 Series
1

For some reason when I print something large and it completes the bed lowers to its lowest position but it does not appear that it knows when to stop and it just grinds and sounds like the printer is going to break. I rush to power it off and then when I power it back on I have to raise the bed manually to about half way up in order to be able to successfully home the printer. What could be wrong and is anyone else having this issue?

2

I have not seen it where it gets the “grinding” noise at the end of a print. The end gcode for this is:

{if (max_layer_z + 100.0) < 250}
    G1 Z{max_layer_z + 100.0} F600
    G1 Z{max_layer_z +98.0}
{else}
    G1 Z250 F600
    G1 Z248
{endif}

If the maximum print height is less than 150, it will lower the bed about 100mm, otherwise it will go to 2mm up from the bottom.

What everyone DOES see, though, is if the bed ends up close to the bottom and you start a new print, it pushes the bed lower and makes that hideous sound. The printer really should keep track of where the bed is between prints, or use the current sensing it has for X and Y to know when to stop for Z.

The sound is (mostly) harmless, but it’s not a good look.

5 Likes
3

I’ve had that happen to me, as well as when I start a new print and the “Z” drops too much, hear the grinding then goes back up for homing.

1 Like
5

This happens when you start a new print after a large print.
After a large print the bed will drive to the bottom, if you start a new print it is in the start gcode to lower the bed again before moving the head.

6

Thank you everyone, it is good to know that I am not the only one experiencing this. It is highly concerning when it happens as I know that sound cannot be good.

1 Like
7

Bump!

This still appears to be an issue 10 months later on P1S :neutral_face: - I get grinding and cracking noises, sounds like something is going to break.

Surely this can be resolved with firmware update.