scattered spourious polygons.....

classic Classic list List threaded Threaded
4 messages Options
Reply | Threaded
Open this post in threaded view
|

scattered spourious polygons.....

bboett
Hello!

in case anyone has some time to spare..... i made for the study of my wife these handles:

i remove from a cylinder the shape of my doorknob, done with a rotate_extrude circle, i am maybe getting tired of looking at the thing :D but i don't get it why there's stuff hanging in the air on both ends of the clamp? the thing i used for difference is longer than the cylinder i am excavacating, this should do the job?

and another question:
is there a way to pass the knob module a shape to extrude?
if someone wants to make that handle with some other strange shape, he will have to dig into the module.... passing the shape as argument to the module, is that somehow possible?

thanks in advance!

--
ciao
Bruno

===========================================
http://nohkumado.eu/, http://aikido.nohkumado.eu/,
http://aikido.zorn.free.fr

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Reply | Threaded
Open this post in threaded view
|

Re: scattered spourious polygons.....

JordanBrown
On 3/20/2020 2:10 PM, Bruno Boettcher wrote:
Hello!

in case anyone has some time to spare..... i made for the study of my wife these handles:

i remove from a cylinder the shape of my doorknob, done with a rotate_extrude circle, i am maybe getting tired of looking at the thing :D but i don't get it why there's stuff hanging in the air on both ends of the clamp? the thing i used for difference is longer than the cylinder i am excavacating, this should do the job?

No, the thing you're subtracting out isn't longer than the thing you're extracting it from.

For your knob() module, when knobrad is non-zero (as it is here), you drop into the curved-part handling at 52-57, and there the "length" is based on "alpha", not based on "len".  The two use the same "alpha" and so you end up with the issues you see here.


and another question:
is there a way to pass the knob module a shape to extrude?
if someone wants to make that handle with some other strange shape, he will have to dig into the module.... passing the shape as argument to the module, is that somehow possible?

Yes, though it might be a little tricky - especially when you want it to fix into the rest of the device.

Did you mean to pass a 2D shape to knob(), or a 3D shape to doorknob()?  The concepts are the same.

You use the children() feature.

For instance, you might want something sort of like this:
module handle(len) {
    difference() {
        linear_extrude(height=len) {
            offset(r=2) children();
        }
        translate([0,0,-1]) linear_extrude(height=len+2) {
            children();
        }
    }
}

handle(10) {
    circle(d=20);
}

translate([40,0,0]) handle(10) {
    square(20, center=true);
}

translate([80,0,0]) handle(10) {
    circle(d=20, $fn=6);
}

yields:



_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Reply | Threaded
Open this post in threaded view
|

Re: scattered spourious polygons.....

Ronaldo
In reply to this post by bboett
i remove from a cylinder the shape of my doorknob, done with a rotate_extrude circle, i am maybe getting tired of looking at the thing :D but i don't get it why there's stuff hanging in the air on both ends of the clamp? the thing i used for difference is longer than the cylinder i am excavacating, this should do the job?

I have gotten a clean shape by  changing the code line:

knob(knobdia+luft, knoblen+2,knobrad);

to 

knob(knobdia+luft, knoblen+2,knobrad+2);

in the doorknob() module.

and another question:
is there a way to pass the knob module a shape to extrude?

Yes, as a children()

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Reply | Threaded
Open this post in threaded view
|

Re: scattered spourious polygons.....

bboett
awesome thanks ,to both, too much looking sometime impaires the brain :D
i will try with the children, and Jordan yes for starters i have one door where the knob has a form like a sort of F shape....
lets see if i manage that one
but for the moment the printer is busy printing the handles for the main doors....

if ever someone wants to make look this thing better (smoother), feel free :) its on github....
ciao
Bruno
ciao


Am Fr., 20. März 2020 um 23:07 Uhr schrieb Ronaldo Persiano <[hidden email]>:
i remove from a cylinder the shape of my doorknob, done with a rotate_extrude circle, i am maybe getting tired of looking at the thing :D but i don't get it why there's stuff hanging in the air on both ends of the clamp? the thing i used for difference is longer than the cylinder i am excavacating, this should do the job?

I have gotten a clean shape by  changing the code line:

knob(knobdia+luft, knoblen+2,knobrad);

to 

knob(knobdia+luft, knoblen+2,knobrad+2);

in the doorknob() module.

and another question:
is there a way to pass the knob module a shape to extrude?

Yes, as a children()
_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org


--
ciao
Bruno

===========================================
http://nohkumado.eu/, http://aikido.nohkumado.eu/,
http://aikido.zorn.free.fr

_______________________________________________
OpenSCAD mailing list
[hidden email]
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org