Question about 3D printed case


05 Mar 2020, 17:56

Like a true keeb junkie, i jumped into ordering this as a case for my 40% without any experience nor knowledge about working with 3d printed object.

So the finished product has this little extra stuff at the edge on every side, how do I get rid of it without damaging the surface.


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05 Mar 2020, 19:27

Could use fine sandpaper or a dremel, or carefully trim it with an xacto knife.

From what I remember when I had access to a 3d printer, it would overfill the first layer like that by default for better adhesion to the bed, but it was adjustable in software.


05 Mar 2020, 22:56

What number of sand paper would you recommend? Like 1000 and such.

Sorry for the funny wording, i have never worked with sandpaper before and from what i know from youtube there are 200 sandpaper 400 etc as indication of how rough it is.

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Elder Messenger

05 Mar 2020, 23:58

I have not personally experienced this, but I would consider scraping it with a razor knife first.

For sandpaper, 400 grit should be plenty fine enough. Those polishing papers take away so little material you could spend all afternoon on it.

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06 Mar 2020, 02:04

Hi, highly recommend using knife in addition also flat cutters/nippers to remove the material.

Sanding should only be done later and in a progressive grit. The little edges are long strands from the printing process and the plastic might sort of delaminate at the edges if you try to sand it first. As its of course connected to the plastic beside it.


06 Mar 2020, 02:29

"Progressive grit" ⇒ use a coarser grit, clean, then use a finer grit, clean, ... and repeat with even finer grits until you are satisfied. The exact grits don't matter, only that each next grit should be just under twice the previous grit.
BTW, around 1000 is very fine: the next higher would be a polishing compound and a rag.

However, In this case, I would maybe sand the bottom in 320 grit or so to make it perfectly level, and then sand the edges lengthwise where there is flashing. Do wrap (or glue) the sandpaper around something flat to use as a "sanding block" to get flatness.


06 Mar 2020, 09:46

Thanks all. Noted and will run this little project further this weekend.

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06 Mar 2020, 12:32

we miss an important bit. what material is that?

if PLA for example it's not easy to sand and absolutely do not use rotary tools (dremel)


06 Mar 2020, 13:26

It is PLA! I dont have rotary tool anw, i was planning to sand it by hands

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06 Mar 2020, 13:38

Recommendations in the order of importance:
  • set the printer z-height and the first layer thickness better to minimize the problem while still having good bed adhesion
  • chamfer the bottom of the model before printing it
  • use an utility knife to cut/scrap the rim off (this is typically not needed if you do the two previous points well)

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06 Mar 2020, 14:25

ntv242 wrote:
06 Mar 2020, 13:26
It is PLA! I dont have rotary tool anw, i was planning to sand it by hands
use a hobby knife to scrape off the excess and then sand it starting from around 400. You can go to 600 or 800 if you want it smoother, but it really takes a lot of time.

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