Quality problem

Hi all,

I try to print THIS object but unsuccessful

I use CuraEngine and the settings are:
Speed and Quality
Structures
Extrusion
Advanced
The temperature is 185°C
Material: PLA
The bed is COLD glass covered with PVA glue mixed in water 50/50.

As you can see I use RAFT for better adhesion and have not problems with it. The first 3 layers from the RAFT are OK. The problem begins after 2-nd or 3-th object layer.

No matter what pattern I use for filling and what speed, always gets notching surface. I can not get a smooth layer in any case.

I tried with / without cooling, decreased / increased the speed, decreased / increased the amount of the filament, increased the percentage of overlap between the infill and the perimeter .... The result is always disgusting.

Pic1, Pic2, Pic3, Pic4, Pic5, Pic6, Pic7, Pic8


I printed different objects and they are not so bad.

Pic1, Pic2, Pic3, Pic4

But even on them the quality is not perfect

May be my the wall of this are too narrow....


What is wrong?

It looks like over extruding and / or retraction settings. Have you run through the calibration guide (reprap.org)?

Thank you 3dkarma for the answer,

You are right for the overextruding.

Until yesterday, I was working with incorrect value of the extruder steps: 94-97 steps/mm. Yesterday I measured it a couple of times, and set it correctly to 84 steps/mm.

With larger values (94-97 steps/mm), I ​​had the problems, described above, namely:
- The surface was so notched, that the nozzle began to abut in the "cliffs", and even to miss steps.
- The amount of the filament was so much that part of it comes out through the thread of the nozzle, burns and falls over the piece.
+ The walls of the piece becomes almost perfect.

Pic1

I use CuraEngine, because it makes better Raft than Slic3r, and the parts adheres perfectly to the bed.
However, with both CuraEngine or Slic3r, the first (solid) layers (not raft) are Ok.
No mater wich settings for the Extruder I use, Immediately after the first not solid layer, began to appears holes on the surface. It becomes slightly serrated and the diameter of the holes grows with each layer.

Pic1, Pic2, Pic3


Even after 6 solid layers on the top, holes can not be filled completely. Separately, the sides of the piece become not smooth but jagged.

Pic1, Pic2, Pic3

​
With both settings for the Extruder, I made tests with different feedrates, Z retracts and infill patterns, without positive results.

I have to use more than 90% infill to be sure fot the results.

Can someone help me with the idea how to avoid notched surface and how to fix the walls?

I'm totally confused by the settings.

Thank you in advance

Edited 1 time(s). Last edit at 09/04/2014 02:22AM by DBS.

your infill and inner perimeter are probably too fast for your design. also first layer height should be increased to 0.15 as well. normally first layer height is thicker or the same. if first layer is too low and flow is too high the feed stock can begin to skip because the back-pressure is too high.

what seems to be happening to me is a loss of pressure in the the nozzle during infill structure, and or tearing of bridging layer across 1st top layer. slowing printing down at these steps or increasing temps helps filament stretch more across the gaps.

I'm unfamiliar with curaengine in detail. have you thought of using cura on its own?

The promlem was with the feedrates.


As you can see, The results are not the best, but comparing with my preview pritns, this is almost perfect.

Base line thickness: 0.3 mm

Pic1,

Interface thickness: 0.2 mm

Pic2,

The first object layer: 0.15 mm

Pic3,


The final result:

Pic4, Pic5, Pic6

The feedrate was 40mm/s max for app operations. Unfortunatelly this is a bad news for me - it is impossible to print lagre objects with 0.2mm nozle.

Thanks to all for the help

Best Regards

Quote
jamesdanielv
I'm unfamiliar with curaengine in detail. have you thought of using cura on its own?

The engine is the core of the Cura program. It can be accessed from the shell to be used independently of the full program. For example using it on a Pi or BBB. The parameters are taken from an .ini file the same as in the full Cura version.