Hi,

Guest

L

laich2@gmail.com

Tue, Sep 13, 2022 10:14 PM

Hi,

Anyone know where I can get the OpenSCAD model of the “Helical Spring” animation in the **linear_extrude** section? (https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#linear_extrude)

best regards

sc

Hi,
Anyone know where I can get the OpenSCAD model of the “Helical Spring” animation in the **linear_extrude** section? (https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#linear_extrude)
best regards
sc

JB

Jordan Brown

Wed, Sep 14, 2022 1:12 AM

On 9/13/2022 3:14 PM, laich2@gmail.com wrote:

Anyone know where I can get the OpenSCAD model of the “Helical Spring”

animation in the *linear_extrude* section?

(https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#linear_extrude)

No, but a note: you might think that linear_extrude with a twist is a

good way to generate helix-like shapes, but it really isn't. The

problem is that you usually want to specify a cross-section across the

helix - nearly, but not precisely, a vertical cross-section, while what

you would have to supply with linear_extrude is a horizontal cross-section.

To get a helix with a round cross-section like this:

what you need to give to linear_extrude is a shape like this:

I'm sure that one of the mathematicians could tell you how to generate

that shape - I sure can't. I generated it by using a sweep function to

create the helix, and then taking a cross section of the helix.

Here's that helix, using BOSL2's path_sweep module:

```
include <BOSL2/std.scad>
r = 20;
path_sweep(circle(5), [
for (i=[0:10:900]) [ r*cos(i), r*sin(i), i/10 ]
]);
```

On 9/13/2022 3:14 PM, laich2@gmail.com wrote:
>
> Anyone know where I can get the OpenSCAD model of the “Helical Spring”
> animation in the *linear_extrude* section?
> (https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#linear_extrude)
>
No, but a note: you might think that linear_extrude with a twist is a
good way to generate helix-like shapes, but it really isn't. The
problem is that you usually want to specify a cross-section across the
helix - nearly, but not precisely, a vertical cross-section, while what
you would have to supply with linear_extrude is a horizontal cross-section.
To get a helix with a round cross-section like this:
what you need to give to linear_extrude is a shape like this:
I'm sure that one of the mathematicians could tell you how to generate
that shape - I sure can't. I generated it by using a sweep function to
create the helix, and then taking a cross section of the helix.
Here's that helix, using BOSL2's path_sweep module:
include <BOSL2/std.scad>
r = 20;
path_sweep(circle(5), [
for (i=[0:10:900]) [ r*cos(i), r*sin(i), i/10 ]
]);

HL

Hans L

Wed, Sep 14, 2022 7:15 AM

I have an old helical coil design on thingiverse which you can try:

https://www.thingiverse.com/thing:1098806

On Tue, Sep 13, 2022 at 8:12 PM Jordan Brown openscad@jordan.maileater.net

wrote:

On 9/13/2022 3:14 PM, laich2@gmail.com wrote:

Anyone know where I can get the OpenSCAD model of the “Helical Spring”

animation in the *linear_extrude* section? (

https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#linear_extrude

)

No, but a note: you might think that linear_extrude with a twist is a

good way to generate helix-like shapes, but it really isn't. The problem

is that you usually want to specify a cross-section across the helix -

nearly, but not precisely, a vertical cross-section, while what you would

have to supply with linear_extrude is a horizontal cross-section.

To get a helix with a round cross-section like this:

what you need to give to linear_extrude is a shape like this:

I'm sure that one of the mathematicians could tell you how to generate

that shape - I sure can't. I generated it by using a sweep function to

create the helix, and then taking a cross section of the helix.

Here's that helix, using BOSL2's path_sweep module:

include <BOSL2/std.scad>

r = 20;

path_sweep(circle(5), [

for (i=[0:10:900]) [ r*cos(i), r*sin(i), i/10 ]

]);

OpenSCAD mailing list

To unsubscribe send an email to discuss-leave@lists.openscad.org

I have an old helical coil design on thingiverse which you can try:
https://www.thingiverse.com/thing:1098806
On Tue, Sep 13, 2022 at 8:12 PM Jordan Brown <openscad@jordan.maileater.net>
wrote:
> On 9/13/2022 3:14 PM, laich2@gmail.com wrote:
>
> Anyone know where I can get the OpenSCAD model of the “Helical Spring”
> animation in the *linear_extrude* section? (
> https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#linear_extrude
> )
>
>
> No, but a note: you might think that linear_extrude with a twist is a
> good way to generate helix-like shapes, but it really isn't. The problem
> is that you usually want to specify a cross-section across the helix -
> nearly, but not precisely, a vertical cross-section, while what you would
> have to supply with linear_extrude is a horizontal cross-section.
>
> To get a helix with a round cross-section like this:
>
>
> what you need to give to linear_extrude is a shape like this:
>
>
>
> I'm sure that one of the mathematicians could tell you how to generate
> that shape - I sure can't. I generated it by using a sweep function to
> create the helix, and then taking a cross section of the helix.
>
> Here's that helix, using BOSL2's path_sweep module:
>
> include <BOSL2/std.scad>
> r = 20;
> path_sweep(circle(5), [
> for (i=[0:10:900]) [ r*cos(i), r*sin(i), i/10 ]
> ]);
>
>
> _______________________________________________
> OpenSCAD mailing list
> To unsubscribe send an email to discuss-leave@lists.openscad.org
>

RD

Revar Desmera

Wed, Sep 14, 2022 8:13 AM

If you're going to use BOSL2, then `spiral_sweep()`

already exists for just this purpose:

include <BOSL2/std.scad>

spiral_sweep(circle(5), h=90, r=20, turns=2.5);

- Revar

On Sep 13, 2022, at 6:12 PM, Jordan Brown openscad@jordan.maileater.net wrote:

On 9/13/2022 3:14 PM, laich2@gmail.com mailto:laich2@gmail.com wrote:

Anyone know where I can get the OpenSCAD model of the “Helical Spring” animation in the linear_extrude section? (https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#linear_extrude https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#linear_extrude)

No, but a note: you might think that linear_extrude with a twist is a good way to generate helix-like shapes, but it really isn't. The problem is that you usually want to specify a cross-section across the helix - nearly, but not precisely, a vertical cross-section, while what you would have to supply with linear_extrude is a horizontal cross-section.

To get a helix with a round cross-section like this:

<Esv568UuTkLejpfN.png>

what you need to give to linear_extrude is a shape like this:

<kFWxNdUdBzrBU5fr.png>

I'm sure that one of the mathematicians could tell you how to generate that shape - I sure can't. I generated it by using a sweep function to create the helix, and then taking a cross section of the helix.

Here's that helix, using BOSL2's path_sweep module:

include <BOSL2/std.scad>

r = 20;

path_sweep(circle(5), [

for (i=[0:10:900]) [ r*cos(i), r*sin(i), i/10 ]

]);

OpenSCAD mailing list

To unsubscribe send an email to discuss-leave@lists.openscad.org

If you're going to use BOSL2, then `spiral_sweep()` already exists for just this purpose:
include <BOSL2/std.scad>
spiral_sweep(circle(5), h=90, r=20, turns=2.5);
- Revar
> On Sep 13, 2022, at 6:12 PM, Jordan Brown <openscad@jordan.maileater.net> wrote:
>
> On 9/13/2022 3:14 PM, laich2@gmail.com <mailto:laich2@gmail.com> wrote:
>> Anyone know where I can get the OpenSCAD model of the “Helical Spring” animation in the linear_extrude section? (https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#linear_extrude <https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#linear_extrude>)
>>
>
> No, but a note: you might think that linear_extrude with a twist is a good way to generate helix-like shapes, but it really isn't. The problem is that you usually want to specify a cross-section across the helix - nearly, but not precisely, a vertical cross-section, while what you would have to supply with linear_extrude is a horizontal cross-section.
>
> To get a helix with a round cross-section like this:
> <Esv568UuTkLejpfN.png>
>
> what you need to give to linear_extrude is a shape like this:
>
> <kFWxNdUdBzrBU5fr.png>
>
> I'm sure that one of the mathematicians could tell you how to generate that shape - I sure can't. I generated it by using a sweep function to create the helix, and then taking a cross section of the helix.
>
> Here's that helix, using BOSL2's path_sweep module:
> include <BOSL2/std.scad>
> r = 20;
> path_sweep(circle(5), [
> for (i=[0:10:900]) [ r*cos(i), r*sin(i), i/10 ]
> ]);
>
> _______________________________________________
> OpenSCAD mailing list
> To unsubscribe send an email to discuss-leave@lists.openscad.org

RW

Raymond West

Wed, Sep 14, 2022 12:51 PM

here's some generic code for spirals/threads, whatever.

clw = true; // direction of spiral

p = 15; // pitch of spiral

n = 3.5; // number of 'threads'

res = 100; // number of 'steps' in circle

di = 20; // diam of os of spiral

d = 5; // diam of 'wire'

////////////////////

t = n*res; //total number of steps

s = (res/360)*di/2; // width of profile

v = p/res; // vertical shift per inc of rotation

//a = 360/res; // angle per step

a=clw==true ? 360/res : -360/res;

module xsec(){

$fn=80;

translate([di-(d/2),0,0])

rotate([90,0,0])

//cylinder (d=d,h=s/2); // whatever 'profile' you like

cube([d,d,s/2],true);

}

for (i=[0:1:t]){

translate([0,0,i*v])
rotate([0,0,i*a])

xsec();

}

It's relatively simple to change the profile or resolution as required,

to make buttress threads, Whitworth profile, whatever. Easy enough to

convert to a function/module with relevant parameters, change

resolution, etc..

On 13/09/2022 23:14, laich2@gmail.com wrote:

Hi,

Anyone know where I can get the OpenSCAD model of the “Helical Spring”

animation in the *linear_extrude* section?

(https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#linear_extrude)

best regards

sc

OpenSCAD mailing list

To unsubscribe send an email todiscuss-leave@lists.openscad.org

here's some generic code for spirals/threads, whatever.
clw = true; // direction of spiral
p = 15; // pitch of spiral
n = 3.5; // number of 'threads'
res = 100; // number of 'steps' in circle
di = 20; // diam of os of spiral
d = 5; // diam of 'wire'
////////////////////
t = n*res; //total number of steps
s = (res/360)*di/2; // width of profile
v = p/res; // vertical shift per inc of rotation
//a = 360/res; // angle per step
a=clw==true ? 360/res : -360/res;
module xsec(){
$fn=80;
translate([di-(d/2),0,0])
rotate([90,0,0])
//cylinder (d=d,h=s/2); // whatever 'profile' you like
cube([d,d,s/2],true);
}
for (i=[0:1:t]){
translate([0,0,i*v])
rotate([0,0,i*a])
xsec();
}
It's relatively simple to change the profile or resolution as required,
to make buttress threads, Whitworth profile, whatever. Easy enough to
convert to a function/module with relevant parameters, change
resolution, etc..
On 13/09/2022 23:14, laich2@gmail.com wrote:
>
> Hi,
>
> Anyone know where I can get the OpenSCAD model of the “Helical Spring”
> animation in the *linear_extrude* section?
> (https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#linear_extrude)
>
> best regards
>
> sc
>
>
> _______________________________________________
> OpenSCAD mailing list
> To unsubscribe send an email todiscuss-leave@lists.openscad.org

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