Help thinning a prosthetic Ear so its lighter and more flexible

[HarryJones]

I work in Prosthetics and this is my first try using 3d priting. We scanned an ear and obtained some skin like elastic filament to print it in.
Even the softer filament is stiff when printed so I would like to thin the STL file. Ideally the base would just be a thin sheet (because it will stick on with glue) and then everything above that is thinner.
Ive tried a few tools but not got anywhere near to getting the ear thinned (so maybe its about 1-2mm thick and not 4-5mm thick.
Would anybody be able to try and thin it and advise me how they did it? I would be very grateful and it will eventually help people

I tried to upload the stl file and each time it never went in the list of uploaded files so I could not drag it to the bottom box to attach to this, what might I be doing wrong?

[HarryJones]

ok so I saw another post explaining uploads arent working so Ive uploaded the file to another forum so it can be grabbed
https://www.3dhubs.com/talk/thread/s...inning-stl-ear

[ralphzoontjens]

I can do it if you want. So you want the ear to be hollow, i.e. leaving the outer surfaces in tact and removing the inner section of the thick parts?
If you can use Cura as a slicer for your 3D printer, you can also hollow it out there by using 2mm wall thickness and 0% infill.

[curious aardvark]

basically any slicer will let you do this.

You can change any aspect of the size of a model and also how many shells and the amount of infill you use.

I think reprapper tech made the skin coloured flezible filaments.

ideally you want 2-3 shells and probably 10% infill. Given the shape of an ear you it might look abit weird with just 2 shells. but it's the number of shells that control to a large extent how stiff flexible filaments get.

But sounds like it should be doable in the slicer.

What slicer are you using ?

[HarryJones]

I havent got as far as using a slicer yet, is it the slicer and not the mesh/cad software that does hollowness?
Also not quite sure what you mean by 2 or 3 shells, if somethings hollow doesnt it have one shell?

[curious aardvark]

ah - no.
The slicer is actually the most important part of the 3d prototyping chain.

It's the software that prepares the part for printing by slicing it into layers of the thickness specified.
It can also do a lot of other things as well.

So you can take a completely solid model. Resize it it all or just selected aixs (length, width, height) you can also stipulate what sort of infill the model has. basically creating a honeycomb interior of whatever pattern and density you like. It also determines how many solid outlines, and top and bottom layers you have - shells.

So you can easily take a solid model, resize it and print it completely hollow, or with variable infill - just using the slicer.
So for one example that would most likely be slicer based. if you were to make an ear for a child. And have to produce different sized ones as the kid grew older. You simply load the orgnal file into the slicer and resize it before printing.

Ideally you should only be working with solid models for 3d printing. Otherwise it gets a bit more complicated :-)


this is what a good slicer can do: https://www.simplify3d.com/

There are free slicers around, notably cura and slic3r - personally I think simplify3d is definitely worth the money.

So through the slicer you can not only resize the ear to whatever thickness you like, but also adjust the infill and shell settings to give exactly the flexibility you require.