The Extruded Material Does Not Stick On Print Bed


1.   The gap between the hotend and the print bed, or Z-offset, is too large. On the first layer, the offset should be        about 0.2mm, or the thickness of a sheet of card stock paper. Refer to (pg.19) for steps to configure the Z-offset.

2.  The adhesion of the print bed is too low. Applying glue stick, masking tape, or spray mount are all known                  methods of adding adhesion.

3.  The hotend temperature is too low, causing the extruded material to cool and harden before fully contacting the      print bed. Increase the hotend temperature by about 5°C and retry.

4.  If there is melted material or other foreign substances on the hotend surface, it may pick up and drag the                 extruded material. Keep the hotend tip clean.

5.  The print speed may be too fast, causing the extruded material to be pulled off from the hotend’s movement.
     The first few layers should be printed slowly to increase stability.

Never touch the hotend with unprotected skin while it is hot as it will result in burns!
Let the hotend cool down completely before proceeding to fix it
.


Printed Dimensions Differ From CAD Model Dimensions

                                                                                        fig.1 - Original 3D Model Dimensions    V.S   Printed Model Measurements Are Off

                                                 
                                      fig.1 - Original 3D Model Dimensions    V.S   Printed Model Measurements Are Off

If the length and width are both uniformly larger or smaller than 50mm by an unsatisfactory amount, then the firmware can be edited to compensate this difference. ( Dimensional Accuracy Test )

 

                                      fig.2 - Original 3D Model Dimensions    V.S   Printed Model Measurements Are Different


                                      fig.2 - Original 3D Model Dimensions    V.S   Printed Model Measurements Are Different

If there is a difference between the length and width dimensions of the printed model itself, then it indicates that the assembly was not done precisely. An inspection of all structural components is recommended. Make sure there are no gaps between all extrusions and their connected pieces. Make sure all steel ball joints are fastened to
the end. Make sure the carriages are flush and secure to the slide seat and that the slide rails are centered to the 2040 extrusions along their entire lengths.


Intermittent Extrusion During Printing

     fig.3 - Intermittent Extrusion During Printing

     fig.3 - Intermittent Extrusion During Printing


If the extrusion seems to be intermittent during printing, here are multiple possible causes and solutions:

1. The extruder drive gear should be securely fastened to the motor shaft and clean of filament residue.

2. The extruder spring, if installed properly, should apply ample pressure on the filament between the plunger arm and the extruder drive gear.



3.  Check to see if the DRV8825 driver chip for the extruder motor has the proper voltage set (0.4V). To check if it is damaged, shut down and unplug the power and usb cables. Then swap the extruder motor’s driver chip with the chip from another axis. If the functions like auto home work on all axes, then the driver chip works fine.

4.  Check if the hotend temperature fluctuates too much by monitoring the status screen on the printer LCD display      or through Pronterface. If the temperature is too far below the target temperature (eg. 20°C below) it will                disable extrusion. Recalibrate PID values if this is the case.

5.  Foreign particles, metal burring, solidified filament in the hotend may all cause partial blockage of the hotend.          Use a 0.3mm drill bit to clean the hotend nozzle.

6.  Detach the Teflon tube from the quick connectors on both ends and try to slide the filament through. If there is a      lot of resistance then the tube may have been bent, warped or clogged. If it cannot be trimmed, a replacement        will be needed.

7.  If the hotend has been overheated before, the teflon tube inside may have warped and will not be usable. It will        need to be replaced.


Print Result Has Very Rough Surface

                                      fig.4 - Good vs Bad Print Surface

                                     
fig.4 - Good vs Bad Print Surface

 

 

Hotend Temperature Set Too High

Overheating PLA will cause it to gas, resulting in bubbles that will be visible in the print result. With opaque materials, the surface may be cloudy or very rough, and on clear materials it will become more opaque or foggy. Reduce the hotend temperature.
 


Printed Result Has Wobbly Layers

              fig.5 - Wobbly Layers


              fig.5 - Wobbly Layers



Wobbly layers, or layers that do not stack up in a consistent and aligned manner (fig.5) most likely indicate that the effector assembly is not securely fastened.

Refer to for effector assembly inspection to fix this problem.


Printed Model Appears To Be Skewed

                               fig.6 - Skewed Print Result

                               fig.6 - Skewed Print Result

 

The skewed look (fig.6), called “slip”, usually results from a malfunctioning driver chip on one or more of the three axes.

Observing how the model is skewed or how each of the axes moves while printing may help in pinpointing which axis has the malfunctioning driver chip or has loose parts.


 

Follow these steps to check the axis:

1. Check if the timing pulley is assembled correctly without missing pieces.
2. Check if the timing pulley is clean of any obstruction and foreign particles.
3. Check if all screws are fastened securely.
4. Check if the stepper motor shaft is off-axis.
5. Check if the belt is firm enough.
6. Check if the voltage of the DRV8825 driver chip is correctly set.  ( Link ) 

 

Printed Object Warps On Tapered Or Overhanging Surfaces

fig.7 - Print Orientation And Overhanging Surface

fig.7 - Print Orientation And Overhanging Surface


Generally this kind of warping (fig.1) is caused by heat build-up and insufficient cooling. The printed extruded material should be cooled as soon as possible.



Follow these steps to minimize heat build-up and warping:

1.  Ensure that the side fans are on at maximum speed during while printing this area (fig.2).

2.  Acquire an external fan to further cooling on the printed object.

3.  Use the [Min Layer] to set a longer layer time.

4.  Enable the [Prime Pillar] function to further          delay the layer printing time.


Gaps Appear Between Infill And Loops

                  fig.8 - Gaps Between Infill And Loops


                  fig.8 - Gaps Between Infill And Loops

Case 1 - Effector Cover Too Loose

If the effector cover is loosely secured on the effector, it will cause the hotend to wobble and therefore lose precision in printing. See Nozzle Inspection for ensuring that the effector cover is securely fastened on the effector along with the hotend assembly. Also ensure that there is no looseness in the structural assembly of the printer, such as the extrusion frames, corner pieces, slide rails, carriages, timing belts, and rods.

 

Case 2 - Unstable or Too Low Temperature

If the temperature is unstable or too low it will affect the smoothness of material extrusion, causing the sharp corners of the print path to have gaps (fig.8). Raising the temperature slightly (eg. 5°C) may solve the problem. To combat temperature instability, ensure that the upper and lower hotend windshields are properly installed and recalibrate the PID settings.

 

Case 3 - KISSlicer Settings

Ensure that the [Loop / Solid Infill Overlap] is set at maximum, 1.00.
Try slightly increasing the [Extrusion Width]. As a final resort, increase the [Flow Tweak].


Print Results In Lots of Strings In Open Sections

fig.9 - Strings Occurring In the Hollow Section of A Vase

fig.9 - Strings Occurring In the Hollow Section of A Vase

Stringing is an anomaly that occurs when the printhead jumps between two parts
of a path that are non-contiguous. A thin spiderweb-like strand appears in the air
following the path of the hotend (fig.4), and can be tedious to remove.
Enable [De-String]  and [Wipe] to minimize this.
Further settings can be found in the Material tab of KISSlicer. Always using this option is recommended
except for special materials such as soft materials.

Prime : 8   Suck : 8   Wipe : 5

Seed [mm/s] : 70

Min Jump [mm] : 1

Trigger [mm] : 1