Effect of infill pattern on warping
I have been trying to find out if the effect of different infill patterns on the severity of warping is significant, but a half-hearted internet search found little of substance to enlighten me.
I have some problems with warping of large, flat parts (entire print bed, but only 10-20mm thick).
So I decided to test it out by printing the same object with different infills.
All to be printed from X3D PLA in white, with 10% infill.
First cab of the rank is 3D-Honeycomb.
Warp-cube-10x20x310-ZH2-40_PLA-EM1.053_0p2Q-10pc_3D-honeycombe.gcode
White PLA from x3D
Printer on bottom half of box, top open, temp in box 27.5
SLIC3R_Settings
0.20mm_Quality_3D-Honeycomb
PRUSA PLA 1.75mm-EMult1.053
Original Prusa i3 MK2 with ZHop_2-40
Start_time: 2016-11-07, 1253hrs
Total_print_time: ongoing
Results:
Still good adhesion and no warping at z3.55
Let me know how you think I can improve the test conditions or object to answer the question.
Re: Effect of infill pattern on warping
You don't mention bed temp and extruder temp. Enclosed, even partially may still be to hot for PLA.
Re: Effect of infill pattern on warping
You don't mention bed temp and extruder temp. Enclosed, even partially may still be to hot for PLA.
I thought warmer is better to reduce warping?
Anyway, i printed three "Warp cubes" with different infill patterns and otherwise fairly similar printing conditions and compared them on a flat marble plate. No enclosure used.
The printing conditions:
Warp-cube-10x20x310_ZH_X3D-W-PLA-EM1.099-230-65C_0p2Q-recti.gcode
ambient 25.5C
SLIC3R_Settings
0.20mm_Quality
X3d-white-PLA-1.75mm_EMult1.099_230-65C
Original PRUSA i3 MK2 with ZHop
Start_time: 2016-11-14, 2023hr
Total_print_time: 2h21min
Results:
Very little warping at ends for about 12mm. This was not obvious when still on bed
No warping on top surface.
W-C-10x20x310_ZH_X3D-W-PLA-EM1.099-230-65C_0p2Q-3DHcomb.gcode
Ambient temp 24.5C, no enclosure.
SLIC3R_Settings
0.20mm_Quality_3D-Honeycomb
X3d-white-PLA-1.75mm_EMult1.099_230-65C
Original PRUSA i3 MK2 with ZHop
Start_time: 2016-11-15, 1645hrs
Total_print_time: 2h40min
Results:
with torch a liftoff of about 5-7mm visible at each end. Not tested this way at previous print.
less lift than linear fill when pushed on end
W-C-10x20x310_ZH_X3D-W-PLA-EM1.099-230-65C_0p2Q-Hcomb.gcode
Ambient temp 24.5C, no enclosure.
SLIC3R_Settings
0.20mm_Quality_Honeycomb
X3d-white-PLA-1.75mm_EMult1.099_230-65C
Original PRUSA i3 MK2 with ZHop
Start_time: 2016-11-15, 1914hrs
Total_print_time: 2h52min
Results:
3-5mm liftoff each end visible with torch while still on bed.
Comparing warp cube results:
Test procedure for warp cubes:
Use 110mm plastic clamp to apply same pressure to the end of the warp cubes.
Apply clamp so that orange plastic is flush with end of the warp cube.
Clamp on marble plate so that the other end lifts up if there is any warping in the clamped end.
Measure height of opposite end above the marble plate.
Clamping at end flush with end, on marble plate, then measure height of other end above marble.
Linear fill:
Lift with first layer down (mm):
Worse end: 5.56
Better end: 5.03
Lift with last layer down (mm):
Previous worse end: less than 0.5
Previous better end: 1.55
Lift in middle with side 1 down (mm): less than 1mm
Lift with side 2 down (mm): 0
Weight (g): 30.65
3D-Honeycomb:
Lift with first layer down (mm):
Worse end: 4.32
Better end: 3.36
Lift with last layer down (mm):
Previous worse end: 1
Previous better end: 1.74
Lift in middle with side 1 down (mm): less than 1mm
Lift with side 2 down (mm): a bit on the other side, too, unsure how that's possible.
Weight (g): 34.80
Honeycomb:
Lift with first layer down (mm):
Worse end: 4.5
Better end: 2.9
Lift with last layer down (mm):
Previously worse end: 1.53
Previously better end: 2.26
Lift with side 1 down (mm): less than 1mm
Lift with side 2 down (mm): very little
Weight (g): 33.63
Re: Effect of infill pattern on warping
My conclusions so far:
1) The infill pattern does not have a very strong effect on PLA warping.
2) If there is better bed adhesion, then the object can end up with more warping of the top layer. The material wants to bend, and if it is allowed to curl up from the bed, then the top layer does not get pulled down as much.
3) The objects also warp sideways
4) Rectilinear had the least warping of the top surface, used the least material and printed the fastest. Because I am mostly interested in a level top surface for my current pet project, I'll use rectilinear infill.
5) To get a more definitive result about the effect of infill pattern on warping, the test should probably be repeated with ABS or something else that is particularly prone to warping.
6) Warping will happen no matter what. It is probably best to design the object so that the warping / material contraction can occur in many small areas where it does not matter, so that the important part of the object ends up straight.
Re: Effect of infill pattern on warping
I found that printing a brim can prevent a lot of warping. You will have to remove the brim of course.
Re: Effect of infill pattern on warping
I'm playing around with a heated build chamber and the following procedure has worked well for me when printing large objects:
-I started with the air temp at 90F to 95F
-After the first few layers are complete, I let the air temp drop to 80F-85F
I am using Hatchbox black PLA.
Here is some interesting information on the subject:
- https://ultimaker.com/en/community/7984-pla-shrink-factor
- http://forums.reprap.org/read.php?154,110647
One of the threads states:
I forget the shrinkage of PLA from glass temp to room temp. It's either 2.5 to 3% or .25 to .3%. I guess it must be the latter (.25 to .3%). So maybe if you scaled everything in Cura (XY only - don't scale Z) that was to be printed in PLA by .3% (and double that for ABS) then that might fix some of the dimension issues. I don't know.
It's more complicated as the lower layers are already cooled to room temp when you put the upper layers down and the upper layers are placed in the proper spot such that the lower layers hold them in place. Mostly. At least until they cool to glass temp. Once at glass temp both layers are "solid" but now the upper layer is still shrinking. No wonder you can see all the thin lines/layers in a print even at .1mm.
What most people do is print everything twice. After printing it the first time measure all the dimensions and if a side is off by say .3mm then change the dimension of that side by .3mm to compensate.
PS: Nice setup, would you mind posting your STL file for the box you have housing the LCD screen?
Re: Effect of infill pattern on warping
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PS: Nice setup, would you mind posting your STL file for the box you have housing the LCD screen?
That little box turned out too small. I could not be bothered redesigning and reprinting it, so I just added some hot melt glue to make it fit well enough.
Here is the code for OpenScad. If you tweak it a bit, you'll have a nice fitting cover. About 4mm taller or so would do, IIRC.
The idea was to leave the original box unchanged, including the clip-on brackets, just stick it all in a bigger box.
Unfortunately I have not been able to get longer data cables to work. Shielding them with aluminium foil is the next little project.
// Need to set $fn to much higher before final rendering. Maybe $fn=150;
$fn=10;
rotate([90,0,0])
union(){
difference(){
cube ([90,155,2.5]);
// Cutting angle into front of base
color ("red"){
rotate([-90,0,0])
linear_extrude (height = 155, centre = false, twist = 0)
polygon(points=[[90,0],[90,-2.5],[87.5,-2.5]]);} }
difference(){
translate([2.5,0,0])
rotate([0,-90,0])
cube ([50,155,2.5]);
translate([0,60,15])
cube([10,20,10]);
}
translate([0,0,47.5])
cube ([40,155,2.5]);}
// Sidewalls
difference(){translate([0,0,-2.5])
linear_extrude (height = 2.5, centre = false, twist = 0)
polygon(points=[[0,0],[0,-50],[40,-50],[90,0]]);
color("blue")
translate([0,0,-3.5])
linear_extrude (height=10 , centre = false, twist = 0 )
polygon(points=[[64,-6],[38,-32],[90,-32],[90,-6]]);}
translate([0,0,155])
linear_extrude (height = 2.5, centre = false, twist = 0)
polygon(points=[[0,0],[0,-50],[40,-50],[90,0]]);