Top Layer won't close

[NozzleMover 0]

Hello everyone!

I am designing a maze and I have some of the top layer areas that just do not want to close.

 

Some Background:

I am using an Orcabot 0.43 / 1.75mm filament / 0.35mm nozzle

I used Slic3r and the print closed all the time but was a littel oversized

Now I am using Cura version  3.2.1 on MAC

I played with 5-10% flow increase

I played with infill 20-30%

I played with infill patters

I tired different skin options

 

All walls have the same dimensions (width is even a multiplier of the nozzle diameter) but some just won't close. These are always the same. The ones that close on the other hand look quit filled up. Also the flat triangle areas are weakly filled at the top layer. Any ideas?

 

This are my current settings:

Maze.curaprofile

 

[SandervG 1,521]

Hi @NozzleMover , thank you for your message. 

I am not really familiar with the Orcabot 0.43, but I could imagine that (if it has belts), they are not tight enough so some movement is lost?

I am inclined to think the solution lies in calibration of your hardware. 

[NozzleMover 0]

Belts are tight. No other part has shown this problem. With Slic3r never had this issue.

 

Any additional ideas?

[Nicolinux 288]

When you use the layer preview in Cura, does it show the same gaps as in the printed object?

[gr5 2,265]

I can't tell if you have underextrusion or if the tops just aren't thick enough.  How many top layers are there ("top thickness" divided by layer height)?  And what is your layer height?

 

It's not underextrusion because it looks fine at the base of the walls.

[NozzleMover 0]

11 hours ago, Nicolinux said:

When you use the layer preview in Cura, does it show the same gaps as in the printed object?

Layer view looks good. All small walls should to be filled with 2 outer and 1 central string of plastic. According to Cura the whole wall should be solid. That is true for the closed ones (I cut into them to verify) but not for the hollow ones.

[NozzleMover 0]

10 hours ago, gr5 said:

I can't tell if you have underextrusion or if the tops just aren't thick enough.  How many top layers are there ("top thickness" divided by layer height)?  And what is your layer height?

 

It's not underextrusion because it looks fine at the base of the walls.

Layer Hight 0.25mm

Nozzle diameter 0.35mm

3 top and bottom layers (0.7mm thickness is calculated by Cura)

I also doubt under extrusion. Printed the same Maze without the maze-part and the inner bottom (in fact a big top layer) look awesome.

 

[NozzleMover 0]

All right. I investigated the phenomenon further. Every wall ofthe maze is 2.1mm wide. Line width is the same as the nozzle diameter. So we should see 6 lines in each wall but I see only 5. When Ponterface is showing the final pass for the top layer I only could see 3 lines. Something is wrong here.

interesting fact: If I check “print outer walls first” (in orang) some walls stay hollow. If I uncheck it (in black) the outer lines seem to be missing in some spots. 

Next I will try a print with 120% scaling and see if the effect disappears. 

Edited April 16, 2018 by NozzleMover
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