Sequential printing bed adhesion issue

[Kief 2]

Hi everybody,

 

I am trying to print a bunch of small objects in PP and i get the best results when printing sequentially and using Magigoo PP glue on my S5 bundle with glass bed. However there is a weird issue that I've noticed. The first object prints perfectly and maybe the second as well, but then it gets a bit sketchy and suddenly some of the objects get really bad bed adhesion and it looks like the brim is under extruding or that the distance between the bed and nozzle is to big and the filament is just sort of layed on top of the bed instead of squeezing the first layer. It seems like there is sometimes a mismatch when the bed is returning to 0 after an object is completed.

 

Does anyone have any tips to troubleshoot and/or fix this issue?

 

Printer: Ultimaker S5

material: Ultimaker PP

slicer: Cura 5.8.0

 

Appreciate any feedback!

[Slashee_the_Cow 438]

If you use some sort of adhesive to aid bed adhesion, it's a good idea to clean your bed with isopropyl alcohol after use.

 

If you're printing the same gcode to put the same object at the same place every time, it's definitely possible that spot is getting dirty. If you have Cura set up to do a "one at a time" print (or you're printing separate gcode files with the same object in different spots) then it's possible the Magigoo is wearing out or something (never used it myself, my printer has a PEI bed which adheres fine) before it gets to that spot.

 

If you think it's not going down to the correct Z height after a print, it's possible that it might be hitting a bit of leftover adhesive or something?

[Kief 2]

7 hours ago, Slashee_the_Cow said:

If you use some sort of adhesive to aid bed adhesion, it's a good idea to clean your bed with isopropyl alcohol after use.

 

If you're printing the same gcode to put the same object at the same place every time, it's definitely possible that spot is getting dirty. If you have Cura set up to do a "one at a time" print (or you're printing separate gcode files with the same object in different spots) then it's possible the Magigoo is wearing out or something (never used it myself, my printer has a PEI bed which adheres fine) before it gets to that spot.

 

If you think it's not going down to the correct Z height after a print, it's possible that it might be hitting a bit of leftover adhesive or something?

 

I find that the magigoo works best after adding at least 2 layers and it will degrade after a couple of runs like you suggest so i usually clean and replace it every other run, which seems to give good consistency.

 

I dont think that the issue is leftover adhesive for two reasons: the adhesive layer is quite thin, way thinner than my layer height. and the printer does not "level" after each object is completed, it autolevels at the beginning of the print and thats it. So it should return to "0" on z when starting the next object but it seems like it doesnt always do that and its a little bit off.

 

I've never played around with gcode directly but do you think i could manually alter the gcode to set the z-height for each object? How would i do that in cura? 

[Slashee_the_Cow 438]

4 hours ago, Kief said:

I've never played around with gcode directly but do you think i could manually alter the gcode to set the z-height for each object? How would i do that in cura? 

Are you printing several in the same gcode file in "one at a time" mode?

 

If you're just printing a file for a single object, you can use the Z Offset plugin by the ever awesome @ahoeben, just go to "Marketplace" at the top right and search for it:

If you are printing several in the same file, then that won't help since it will affect all of them.

 

If you are printing several in "one at a time" mode in the same file, then yes, it's possible to edit the gcode to change the Z height for objects individually. It's something I'd normally recommend against since if it isn't done right it can result into the nozzle going down into the bed (which is bad) but if you want I can give you instructions.