Top layer incomplete - please advice

[unchiu]

Hello,

I have this problem, always the top layer is incomplete. How much is missing depends proportionally with top layer area. Please help.

Missing last lines

Missing area settings.fff

My settings

(9.28 KiB) Downloaded 232 times

[CompoundCarl]

Well it's hard to know just from looking at the picture. If you print that part multiple times, does it come out the same way every time? That would help rule out other less consistent causes like extruder jams and stuff like that.

Have you tried printing it with coasting turned off?

[unchiu]

Yes, printing same object the defect is the same. If I print a test cube then the missing part is smaller, just a corner is missing. So I think the missing area size is proportional with top layer area size.
I will try to print with coasting turned off and post the result. Thanks for anwer.

[unchiu]

Thanks for answer.
The problem is always in the same place. For smaller object the missing print area is smaller too.
Coasting turned off did not solved the problem. When I look to preview in S3D the drawing is complete. But it seems that the printer skip last movement commands and then execute the ending script.

[CompoundCarl]

Well if your printer is skipping commands, that's definitely going to cause the issue!

So you can confirm that the S3D preview shows those moves being printed? They are also in the gcode file? But for some reason the printer isn't doing those moves?

[dkcookie]

I have the exact same issue.
I am using the Marlin firmware on Ramps 1.4, on a Mendel type printer.
Simplify3d 3.0.2

And I have attached my settings:

Prusa Mendel.fff

My settings

(10.85 KiB) Downloaded 228 times

As my picture show I experience the same problem every time I print. If I print more models, it is only the last model that has the problem, which confirms the "skipping rest of instructions" theory.

I have tried to print from SD card and directly though USB - Same result. Is this problem unique to Marlin/Sprinter firmware boards, or does anyone experience this on Ultimaker etc. as well?

[CompoundCarl]

Well if those commands are present in the gcode preview, then they are in the file. So it must mean the firmware is skipping them for some reason.

I know some firmwares in the past had issues where certain commands were buffered while others were not. This meant that if it got a non buffered command near the end of the print, it would execute that command before the others in the buffer and that would cause issues. If you're using Marlin, try adding an M400 command at the top of your ending script, which will make sure all commands in the buffer are executed before continuing.

Similar issue here: https://github.com/MarlinFirmware/Marlin/issues/1605

[unchiu]

Thank you. I will try.