Why are my PLA parts so flimsy :( I printed these cranks for that

3D Printing
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1

Why are my PLA parts so flimsy :frowning:

I printed these cranks for that parametric music box thingi,
but their one arm keep on snapping off when I put it over the pulley.
Eventually I re-inforced it heavily and heated it with a lighter before I could get it on. Previously I didn’t have an issue when I printed it scaled to 90% . But I noticed that a lot of my parts break very easily like this toothpaste roller, I had to glue it back together :frowning: . Are the designs on thingiverse that bad or do I have a slic3r setting problem?

Issues I’m considering

  1. printing too cold - I’m printing at 201 C because higher than that I get some moisture bubbles
  2. too little infil - I reduced this a lot since I figured that too much infil and extruder multiplier made some of the small tower type parts to melt into itself and be nasty deformed
  3. Fan overkill - with these small towers, I also noticed that it was only on the one side, so I added a cpu fan on the other side too, I think that may be my biggest problem right now. Will try to get two smaller fans tomorrow.

#3dprinting

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2

Layer height too high? Layer height should always be <80% of nozzle width. Also, yes too strong of a fan will cool the PLA too quickly.

3

@ThantiK yeah I tried it at 0.2mm and 0.4mm layer height (0.5 nozzle) both snapped :frowning: thx

4

Whats your infill % ? Which printer are you using ? And where did you buy the PLA ?

5

@Shachar_Weis the issues are on solid infil, and it looks solid and if I increase the width there is too much plastic, though i can look at that again. Infil was 0.12 to 0.15 . Printrbot. I also notice that it is not hard enough to pull off a solid appendage from a flat surfice. The pla was sourced from http://openhardware.co.za who imports from somewhere, their have a good reputation among my 3dprint buddies. Thx.

6

Good feedback Anthony, I made a note of that too

7

Got it working now at 185 degrees C, thanks to +Peter van der Walt from http://openhardware.co.za who told me that higher temperature makes the PLA a bit more brittle.