Avoid a sharp corner between two objects
Hi guys;
I am 2 weeks old with OpenSCAD so bear with me if it is an easy one. -
I am wondering how to avoid a sharp corner between two objects in openscad.
Code:
sphere (r=0.3, $fn=50);
rotate([90,0,0])
{
cylinder (h=2, r=0.1, center=true, $fn=20);
}
rotate([0,90,0])
{
cylinder (h=2, r=0.1, center=true, $fn=20);
}
I would like to avoid the sharp edges between the cylinder and sphere.
In a way I want something like an expanding column.
An example: something similar to this but the cylinder is connected to a
sphere and NOT A PLANE.
https://www.thingiverse.com/thing:137984
https://www.thingiverse.com/thing:137984
I tried a few samples using minkowski() function as well, but the outer
surface of the cylinder looks swollen which is not what i actually want.
Any hint please!!
--
Sent from: http://forum.openscad.org/
first two ideas that came to mind... (btw tiny tiny objects - but then I
assume units are mm - too much 3d printing!)
sphere (r=0.3, $fn=50);
translate([.25,0,0]) sphere(r=0.15, $fn=50);
translate([-.25,0,0]) sphere(r=0.15, $fn=50);
translate([0,.25,0]) sphere(r=0.15, $fn=50);
translate([0,-.25,0]) sphere(r=0.15, $fn=50);
rotate([90,0,0]) cylinder (h=2, r=0.1, center=true, $fn=20);
rotate([0,90,0]) cylinder (h=2, r=0.1, center=true, $fn=20);
translate([1.5,1.5,0]) {
hull() {
sphere(r=0.3, $fn=50);
rotate([90,0,0]) cylinder (h=.7, r=0.1, center=true, $fn=20);
rotate([0,90,0]) cylinder (h=.7, r=0.1, center=true, $fn=20);
}
rotate([90,0,0]) cylinder (h=2, r=0.1, center=true, $fn=20);
rotate([0,90,0]) cylinder (h=2, r=0.1, center=true, $fn=20);
}
On 18/10/17 11:39, Katt wrote:
sphere (r=0.3, $fn=50);
rotate([90,0,0])
{
cylinder (h=2, r=0.1, center=true, $fn=20);
}
rotate([0,90,0])
{
cylinder (h=2, r=0.1, center=true, $fn=20);
}
Thanks;
That was a good try and sharing some ideas. The hull() is definitely what I
am not looking for.
The first one, using several spheres at the ends of a cylinder is close but
not ideal.
As such, you don't get a perfect arc shape. The reason why I want
specifically an arc is because I want to mesh it later for fluid flow
calculations. The scale as of now is not an issue as I scale the image. I
deal with micron size.
However, this results in the same sharp boundary between the new sphere and
the main larger sphere.
--
Sent from: http://forum.openscad.org/
On 10/18/2017 06:39 AM, Katt wrote:
Hi guys;
I am 2 weeks old with OpenSCAD so bear with me if it is an easy one. -
I am wondering how to avoid a sharp corner between two objects in openscad.
Code:
sphere (r=0.3, $fn=50);
rotate([90,0,0])
{
cylinder (h=2, r=0.1, center=true, $fn=20);
}
rotate([0,90,0])
{
cylinder (h=2, r=0.1, center=true, $fn=20);
}
I would like to avoid the sharp edges between the cylinder and sphere.
In a way I want something like an expanding column.
An example: something similar to this but the cylinder is connected to a
sphere and NOT A PLANE.
https://www.thingiverse.com/thing:137984
https://www.thingiverse.com/thing:137984
I tried a few samples using minkowski() function as well, but the outer
surface of the cylinder looks swollen which is not what i actually want.
Any hint please!!
A very rough and incomplete suggestion:
With a bit of careful manipulation, removing a torus and tube (as a
module) from each end of your cylinders might do the trick. In this
code, only one end of one cylinder is illustrated.
--Algot
sphere (r=5, $fn=50);
difference(){
rotate([90,0,0])
{
cylinder (h=20, r=3, center=true, $fn=20);
}
// torus
translate([0,5.1,0])
rotate([90,0,0])
rotate_extrude(convexity = 10)
translate([4, 0, 0])
circle(r = 1.5, $fn=20);
translate([0,8,0])
rotate([90,0,0])
tube();
}
rotate([0,90,0])
{
cylinder (h=20, r=3, center=true, $fn=20);
}
// tube
module tube(){
difference(){
cylinder(h=5,r=3,center=true,$fn=20);
cylinder(h=5,r=2.5,center=true,$fn=20);
}}
On 2017-10-18 11:39, Katt wrote:
I am wondering how to avoid a sharp corner between two objects in openscad.
There is some scad code for a 3D fillet. I tried in on your example, and
I also made objects larger for my own convenience and added a fn
variable to let me easily adjust face count. Note when using "in anger"
I'd probably also have a wrapper for fillet that let me turn in on and
off globally and also have local overrides.
Does this do what you want? You'll have to download fillet.scad and
either have in same folder or in library folder.
//
https://github.com/clothbot/ClothBotCreations/blob/master/utilities/fillet.scad
include <fillet.scad>;
fn = 5;
fillet(r=3,steps=5, include=true) {
sphere (r=30, $fn=5*fn);
rotate([90,0,0])
{
cylinder (h=200, r=10, center=true, $fn=2*fn);
}
rotate([0,90,0])
{
cylinder (h=200, r=10, center=true, $fn=2*fn);
}
}
Katt,
What about doing as below:
hull() {
sphere (r=0.3, $fn=50);
rotate([90,0,0]) cylinder (h=.6, r=0.1, center=true, $fn=20);
rotate([0,90,0]) cylinder (h=.6, r=0.1, center=true, $fn=20);
};
rotate([90,0,0]) cylinder (h=2, r=0.1, center=true, $fn=20);
rotate([0,90,0]) cylinder (h=2, r=0.1, center=true, $fn=20);
Just an idea,
Jean-Paul
N1JPL
On Oct 18, 2017, at 8:35 AM, Katt saideep.pavuluri@pet.hw.ac.uk wrote:
Thanks;
That was a good try and sharing some ideas. The hull() is definitely what I
am not looking for.
The first one, using several spheres at the ends of a cylinder is close but
not ideal.
As such, you don't get a perfect arc shape. The reason why I want
specifically an arc is because I want to mesh it later for fluid flow
calculations. The scale as of now is not an issue as I scale the image. I
deal with micron size.
However, this results in the same sharp boundary between the new sphere and
the main larger sphere.
--
Sent from: http://forum.openscad.org/
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