Printing problems
Hello guys,
It's about a month I'm dedicated to 3D printing.
I have the following problem: printed object which have round shapes in the low parts have defects.
I attach the pictures of a head I designed and, as you can see, the neck / throat has a bad extrusion.
Where am i wrong?
The other parts are quite good
I have a Prusa I3 MK2S, i used Slic3r Prusa Edition, the material is PLA mm 1,75.
Thank You in advance! 🙂
Re: Printing problems
You are not wrong, your model is.
3D printing has its limitations and one of them is this throat, or more like the angle of this throat.
The overhang of the chin is just too steep. Your printer will try to print in air which is simply not possible.
By using support structure for the chin you will still end up with scars, but not that obvious ones which you can even sand away using normal wood sandpaper.
You could also try to cut your model in half, to print 2 parts which you can glue thogether. This will lead to a nice finish on the throat but probably a visible line at the area you cut your model.
What worries me more is your first layer.
The ideal first layer shows a nice, smooth and closed surface. In order to get that you will need to lower your nozzle quite a bit, as your first layer has pretty big gaps between the single extrusion lines. To do that, just lower your Live Adjust Z (more negative numbers), until the nozzle squishes the filament a little bit, so the single extrusion lines melt together and create a closed finish.
If you have problems finding the right Live Adjust Z, have a look at this.
You should take your time and work your way through this thread, as it is very helpful.
On page 4 you will find Jeff's "calibration_surface_PLA_75x75@200um_v4" use this to get a perfect first layer (instructions on how to are in the thread).
Re: Printing problems
++ On everything Sherlock said.
1) This model has too steep an overhang. (In order of preference:)
a) Use the "Supports" feature of your slicer. - or -
b) Cut the model as Sherlock said. - or -
c) Tilt the model "back" so the throat and back of head are each about 45degs - now you need a raft for the base.
2) Your first layer is asking for a print to break loose and great havoc.
a) In ADDITION to the thread he pointed to, read this one:
Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…
Re: Printing problems
I want to thank You Sherlock and aaron.s5 for their precious tips.
In the next days i will update this topic about my new print attempts, thanks a lot!
Re: Printing problems
Here we are, 2° attempt 🙂
I printed the head bigger than before, the infill has been raised from 2% to 4%, i used the support materials and i have adjusted the Z to 0,15 mm.
I think the result is better than before, the chin is less defective and the first layer looks better: what do you think about?
Only the problem has appeared about the infill which is visible with spots and that's ugly to see: any suggestions?
Thanks a lot 😉
Re: Printing problems
Your first layer still looks terrible. Can you post a photo of the "Calibration_surface_PLA_75x75@200um_v4.gcode"
from step 6 here:
? This will help us understand your first layer issue.
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I think your Slicer settings are way off. Did you load the .ini file by using "Load Config Bundle..."?
Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage or loss. If you solve your problem, please post the solution…
Re: Printing problems
Hi aaron.s5 thanks first for your disposability and courtesy.
Below You can find the pics of the print tests: on the upper right corner i wrote the Z Adjustment value.
The common part of all three prints is that imagining to divide the square with a diagonal starting from the lower left corner to the upper right corner, the right half is almost always homogeneous, the left half always has cracks.
I'm sorry but having approached me a little while ago in this "world" I do not know what is the .ini file by using "Load Config Bundle; if it can be useful, I use Prusa3D Slic3r MK2 updated to 1.37.1 and Prusa drivers 1.9.0.
Thanks.
Re: Printing problems
You need an even lower live Z. Start around -0.250, based on the progression you show. Also, the diagonal nature may show a slightly off bed leveling.