3D Print challenge in the Z-Axis

[Techanalytic 0]

Hello UM community. I would like to ask you for some help in resolving this problem that i have face with all three prints using the settings recommended by the original source.

1. Manifold (Layer missing at a minimum two locations - Z-Axis)

2. A380 Wings (Left) ( Layer missing at a minimum three locations - Z-Axis)

3. A 380 Wings (Right) (Only a single missing layer - Z-Axis)

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a. Problem

Missing PLA layers in all the above prints in the Z-Axis.

b. Common Problem

I stood them all on the bed after the prints completed and one specific layer at a certain height was missing in two of them (Print 2 and 3, highlighted in blue in the image) and shows a less smoother but printed layer in the 3rd.

c. What i did before printing 1

Too resolve brittle PLA problems (fracturing on minor bends inside the tube when extruded) \ I gave it a 25 second bath in water at 70 degree Celsius and dried it in air before use, that resolved the issue.

d. What i did before printing 3

1. Read up similar issues on the UM community and ensured that i clean my Z-Axis feed rod and lubricate it using the given magnalube.

2. Ensure the screws in the entire UMO+ are all well fastened (with out adding any friction to the X-Y stage) and nothing is loose, such as belt tension etc. (though it was the Z stage causing a problem and that does not use a belt.

3. Reduce the current to all the steppers by adding the command "M907 X1100 Y1100 Z1100 E1250" in the code prior to printing.

4. Added a high speed fan to reduce the heat build up under the UMO+ structure directed towards the Z-Axis stepper. (Temperatures read at stepper outer blocks, X/Y 30 deg Celsius, Z 20 deg Celsius)

e. The Modified Code (M Code in the second last line)

;Sliced at: {day} {date} {time}

;Basic settings: Layer height: {layer_height} Walls: {wall_thickness} Fill: {fill_density}

;Print time: {print_time}

;Filament used: {filament_amount}m {filament_weight}g

;Filament cost: {filament_cost}

;M190 S{print_bed_temperature} ;Uncomment to add your own bed temperature line

;M109 S{print_temperature} ;Uncomment to add your own temperature line

G21        ;metric values

G90        ;absolute positioning

M82        ;set extruder to absolute mode

M107       ;start with the fan off

G28 X0 Y0  ;move X/Y to min endstops

G28 Z0     ;move Z to min endstops

G1 Z15.0 F{travel_speed} ;move the platform down 15mm

G92 E0                  ;zero the extruded length

G1 F200 E3              ;extrude 3mm of feed stock

G92 E0                  ;zero the extruded length again

G1 F{travel_speed}

;Put printing message on LCD screen

M907 X1100 Y1100 Z1100 E1250

M117 Printing...

Can you please suggest some thing to resolve this? Almost 30 hours of print time and several meters lost with no certainty of having a successful print in future. What am i possibly missing?

* Am not getting to see all the 4 images i uploaded in the preview after my third attempt, i hope they are visible once i post this!

Best Regards

Faisal

Edited February 26, 2017 by Guest

[DidierKlein 729]

Could be some underextrusion due to the filament ? Either the spool is near the end and the curvature of the filament is too strong, adding extra friction in the bowden?

Or filament diameter too inconsistent? This can be caused by many things

What is the filament brand?

[Siebet 27]

When it's mostly on the same place on the print, It can be a bed drop...

I had the same problem on my UM2GO, A new leadscrew may help!

You can try to use this guide to solve the problem...