4
$\begingroup$

I just got into 3D printing with an Ender-3 Pro. The test dog printed great, some custom small/thin objects printed good, and now I tried my first big object.

Designed in Tinkercad (link to my (updated) design), exported to .stl, sliced and printed using Cura 4.5.0 with the default 0.2 mm profile (3 layers wall thickness) and 100% infill (for strength), with the extruder at 200 °C and bed at 50 °C. Ambient temperature had been 25-ish °C.

The filament is a brand-new Spectrum Premium PLA (Arctic White). On its box it says it prints at 185-215 °C.

So I got this:

On the magnetic bed (front)

On the magnetic bed (back)

One leg - lower layer view

One leg - side view

Other leg - side view

The top (thinner) sections look OK-ish (there are some visible lines, but meh), but the transition from the bottom sections (thick) to the top has terrible layer separation and warping problems. One side of the base is actually barely holding together when I'm holding it. There is also a smaller problem mid-way at that side of the base, but it's not catastrophic.

  1. Why did that happen? What did I do wrong? How can I print it again and get it nice and strong?

2) I have a handheld "3D print pen". If I use it to fill the gaps manually, how strong will the part be? The part is meant to "hug" the iPad charging port, so that you can hold the iPad in the bed while charging, without pressing the cable on your body and damaging it. nvm that

Using wall thickness of 4, layer height 0.16 mm, 30% infill and 205 °C extruder, this is my (successful) result.

Successful result on the magnetic bed Successful result in action

I also repaired that broken part. Did it for the aesthetics, but it feels quite strong.

Repaired with 3D pen

Improve this question
$\endgroup$
1
  • 1
    $\begingroup$ Good deal on the successful print! $\endgroup$
    – Pᴀᴜʟsᴛᴇʀ2
    Commented Apr 24, 2020 at 2:04

2 Answers 2

Reset to default
5
$\begingroup$

One hundred percent infill is not necessarily stronger than lower values. By having such a high infill figure, the forces on the model as it cools are magnified and not in a particularly good manner.

Consider that you could use twenty to thirty percent infill to get the strength you require for this application, saving filament and time for the print. You've not noted how many wall layers used, but for increased strength, four to five would make for a very strong model.

Improve this answer
$\endgroup$
3
  • $\begingroup$ Thanks! There's a "wall line count" setting, I'm assuming this is what you mean "how many layers". The default (which I used) is 3. If increasing wall layers count increases strength, how is that different from infill? If I use 10 wall layers, for example, so that the whole mass is "walls", wouldn't that be the same result as using 100% infill? $\endgroup$
    – Stratubas
    Commented Apr 23, 2020 at 15:38
  • 1
    $\begingroup$ @Stratubas - Yes, technically it is true you could increase the wall line count to get to this, but rarely ever would come into play. One of the problems with 100% infill is you are retaining a LOT of heat within the print itself. Because of this, it isn't able to cool correctly or quickly enough to setup. It doesn't surprise me your print pulled apart. What I'm surprised about is it didn't pull apart more. Using a 30% infill will most likely cure your ills ... you could probably go down to 20% and still get the same strength and rigidity. Way more than what you need, IMHO. $\endgroup$
    – Pᴀᴜʟsᴛᴇʀ2
    Commented Apr 23, 2020 at 17:06
  • 2
    $\begingroup$ @Pᴀᴜʟsᴛᴇʀ2: Not only are you retaining heat, but if the extrusion is even slightly over the nominal amount of material desired, at 100% infill there's nowhere for the excess to go and it will necessarily exert forces that warp your print (usually even causing slop to extend upward and collide with the nozzle, resulting in the print getting knocked off the bed). $\endgroup$
    – R.. GitHub STOP HELPING ICE
    Commented Apr 24, 2020 at 1:35
0
$\begingroup$

The reason for this sort of error might be either 1) a clogged nozzel, try doing this 2) disturbed bed level,resolve this issue 3) poor filament quality,

Improve this answer
$\endgroup$

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .