Hello everyone,
i am having a problem with the print:
I am printing a rig to insert an aluminum profile 30x30x240mm where i want to print on top.
due to the nature of my .stl bambulab gives me a warning that it might be unprintable (part of it is floating in midair.
)
I am inserting the following code in the first layer after insertion, so that i can enter the profile:
G1 Z100.0 ; move print plate down for user intervention
M400 U1 ; pause for user intervention
M104 S290 ; hot end temperature to 290C
G28 X Y ;Home in X and Y
However after the printhead resumes print, it seems it freaks out due to detecting my profile and does a random movement. It is random as in every of the three tries, the movement was different.
Do i have to deactivate the lidar or something else?
I am a bit clueless on how to proceed.
Any help is appreciated!
Is there are reason you don’t just print all the parts on the bed and insert them into the extrusion afterwards? The top two parts are floating even with the extrusion inserted and will not print.
5 Likes
yes, i am fixing another fiber-reinforced part onto the profile and am printing directly onto this.
Should have mentioned it.
The profile is to prevent warping, There is never printing in midair 
I would avoid trying to print onto inserted parts. Just print a locating jig and glue them on as a post process.
2 Likes
the goal is to use the material properties and fuse it onto the part directly.
It is the same thermoplastic as i am printing. Glueing it on later is disadvantageous
I still advise against it.
My guess is that you will need to trick the slicer into thinking the parts extend to the print bed and manually cut that part out of the code.
Have you used the g-code preview in the slicer to see what the current g-code you’re outputting is doing?
5 Likes
but this still does not explain the erratic behavior.
Get rid of the re-home. If all you’re doing is moving the Z axis, and you don’t actually make contact with the printhead when paused, you don’t need the re-home after unpausing.
2 Likes
Yes i am aware, i did the rehome after the first couple of colisions, thinking i could avoid it this way. but the collision happens after the rehoming anyways
i am trying to print this way now, maybe i can trick the printer… i will remove the "support before inserting the profile
The gcode does not show any unexpected behavior
1 Like
M400 U1 has a built in nozzle wipe IIRC.
You may need to insert a M400 (wait for previous command to complete) on the next line so the wipe sub routine completes before moving to homing.
2 Likes
As Jon said, the issue was due to bambu not printing every layer.
If the “free floating” layer is connected by a sacrificial tower (one is enough, and does not even need to touch the free floating parts) the gcode that is produced will not have artifacts hitting the side walls.
The M400 Command is not necessary, the printer is smart enough to wipe the nozzle and continue with the next G-command afterwards.
2 Likes
Adding the legs was a smart work around.
2 Likes
