Rough start of each print

[tim080 0]

Hi all,

 

I am currently using Cura version 5.6.0 and an Ender 5 Plus printer with BondTech DDX direct drive and Micro swiss hotend. 

 

Attached to this post you can find the problem I am experiencing at the moment.

 

The first series of layers seem to be pressed together, resulting in a very rough print. After some 6-8 layers, this normalizes and the print will mostly continue as expected. What settings could be at the basis of this problem and how can I solve this? 

 

- It could be something with the Z steps, but why does it normalizes after several layers?

- The amount of layers showing the issue is different from the amount of bottom layers.

- It happens with basically all my filaments, both PLA and PETG.

- travel retraction distance is set to 1mm.

 

In addition, as some might notice, the start and/or end of the outer wall are not always properly filled. I am not sure on the direction in this print, but it seems to start either too late or with a blob, or ends the line ending with a blob or too soon, resulting in missing filament.

 

Who can help me fix this?

Many thanks in advance!

 

Tim

[Slashee_the_Cow 438]

I know this one is obvious but I'm going to say it: checked to make sure your bed is level and your Z offset is correct?

[tim080 0]

The bed is indeed as level as I can get it.

I have been playing with the Z offset as well, but to get it right, it seems that I have to adjust it during the print, otherwise the hot end will be either too close to the bed, or so far above it that the first layer won't stick. So the first layer has to be good, then I have to adjust the Z offset on the screen to correct the distance. Which makes a very difficult print each time.

[Slashee_the_Cow 438]

If your bed is level but you have to constantly adjust the Z offset, that sounds like it's most likely something with the printer. That I can think of off the top of my head, here are some possibilities:

• The bed isn't flat
• The bed is moving (or not moving when it should) during printing because at least one of the parts that hold it on the Z axis is either too tight or too loose
• The Z axis motor/s (not that familiar with the printer) has developed brain damage and isn't staying still when it should
• The motherboard has developed minor brain damage and isn't controlling the Z axis correctly
• The printer's firmware has gone haywire and is applying an auto bed levelling mesh completely wrong (FWIW I have an ABL in my startup gcode, but that won't help you if it's reading or using the ABL data wrong)
• Your startup gcode has a home command (G28) which turns off ABL, and doesn't have a command in to turn it back on. My E3V3SE automatically turns ABL back on after being homed but I don't know about other printers. If you want to be sure then after a G28 there should be either a G29 (performs auto bed levelling) or M420 S (which enables the ABL compensation from the last time it measured it)

The effect of almost all of those could diminish as your print gets further up because filament is great at sort of "filling in the gaps" where needed. Even if ABL says a part of your bed is 1mm below another part, it generally stops taking the ABL data into account and just prints completely flat after the first 5-10 layers.