Hi,

Guest

M

mikeonenine@web.de

Thu, Sep 19, 2024 10:37 PM

Something else with teeth that the world has been waiting for: a face spline coupling aka Hirth coupling. I created it some time ago as part of a design, but it had a glitch that turned out to be because the circumference of a small sector of a circle is slightly longer than the straight line across it. This left tiny but visible gaps between the splines.

I thought it would be difficult to parametrise but it was not.

But it still has some sharp edges that need rounding. Any volunteers?

`$fn=100;`

`$vpr=[ 60, 0, 315 ];`

`$vpt=[ 0, 0, 0 ];`

`$vpd=80;`

`/*`

`*/`

`a=60; // Base angle`

`r=12; // Radius`

`n=24; // Number of splines`

`module facespline()`

`{`

`difference()`

`{`

`intersection()`

`{`

`for(i = [1 : n])`

`rotate(i * 360/n)`

`polyhedron( `

`points = [ `

`// Point 0`

`[0, 0, PI*r/2/n*tan(a)],`

`// Point 1`

`[r, r*tan(360/2/n), 0], `

`// Point 2`

`[r, -r*tan(360/2/n), 0], `

`// Point 3 `

`[r, 0, PI*r/n*tan(a)],`

`// Point 4`

`[0, 0, 0]`

`], `

`faces = [ `

`[1,2,3],`

`//[0,2,1], `

`[3,2,0],`

`[3,0,1],`

`[0,2,4], //`

`[0,4,1], //`

`[1,4,2] //`

`]);`

`cylinder(r=r, h=PI*r/16*tan(a)+1);`

`}`

`// Hole`

`translate([0,0,-1])`

`cylinder(r=6, h=5);`

`}}`

`// Face spline coupling`

`rotate([0, 0, $t*360])`

`{`

`translate([0, 0, -3])`

`facespline();`

`translate([0, 0, 3])`

`rotate([0, 180, 360/2/n])`

`facespline();`

`}`

Something else with teeth that the world has been waiting for: a face spline coupling aka Hirth coupling. I created it some time ago as part of a design, but it had a glitch that turned out to be because the circumference of a small sector of a circle is slightly longer than the straight line across it. This left tiny but visible gaps between the splines.
I thought it would be difficult to parametrise but it was not.
But it still has some sharp edges that need rounding. Any volunteers?
`$fn=100;`
`$vpr=[ 60, 0, 315 ];`
`$vpt=[ 0, 0, 0 ];`
`$vpd=80;`
`/*`
`*/`
`a=60; // Base angle`
`r=12; // Radius`
`n=24; // Number of splines`
`module facespline()`
`{`
`difference()`
`{`
`intersection()`
`{`
`for(i = [1 : n])`
`rotate(i * 360/n)`
`polyhedron( `
`points = [ `
`// Point 0`
`[0, 0, PI*r/2/n*tan(a)],`
`// Point 1`
`[r, r*tan(360/2/n), 0], `
`// Point 2`
`[r, -r*tan(360/2/n), 0], `
`// Point 3 `
`[r, 0, PI*r/n*tan(a)],`
`// Point 4`
`[0, 0, 0]`
`], `
`faces = [ `
`[1,2,3],`
`//[0,2,1], `
`[3,2,0],`
`[3,0,1],`
`[0,2,4], //`
`[0,4,1], //`
`[1,4,2] //`
`]);`
`cylinder(r=r, h=PI*r/16*tan(a)+1);`
`}`
`// Hole`
`translate([0,0,-1])`
`cylinder(r=6, h=5);`
`}}`
`// Face spline coupling`
`rotate([0, 0, $t*360])`
`{`
`translate([0, 0, -3])`
`facespline();`
`translate([0, 0, 3])`
`rotate([0, 180, 360/2/n])`
`facespline();`
`}`

BC

Bob Carlson

Thu, Sep 19, 2024 11:40 PM

I was curious what this looks like so I loaded it up and hit F6. I get No Geometry to Render.

-Bob

On Sep 19, 2024, at 15:37, Caddiy via Discuss discuss@lists.openscad.org wrote:

Something else with teeth that the world has been waiting for: a face spline coupling aka Hirth coupling. I created it some time ago as part of a design, but it had a glitch that turned out to be because the circumference of a small sector of a circle is slightly longer than the straight line across it. This left tiny but visible gaps between the splines.

I thought it would be difficult to parametrise but it was not.

But it still has some sharp edges that need rounding. Any volunteers?

$fn=100;

$vpr=[ 60, 0, 315 ];

$vpt=[ 0, 0, 0 ];

$vpd=80;

/*

*/

a=60; // Base angle

r=12; // Radius

n=24; // Number of splines

module facespline()

{

difference()

{

intersection()

{

for(i = [1 : n])

rotate(i * 360/n)

polyhedron(

points = [

// Point 0

[0, 0, PI*r/2/n*tan(a)],

// Point 1

[r, r*tan(360/2/n), 0],

// Point 2

[r, -r*tan(360/2/n), 0],

// Point 3

[r, 0, PI*r/n*tan(a)],

// Point 4

[0, 0, 0]

],

faces = [

[1,2,3],

//[0,2,1],

[3,2,0],

[3,0,1],

[0,2,4], //

[0,4,1], //

[1,4,2] //

]);

cylinder(r=r, h=PI*r/16*tan(a)+1);

}

// Hole

translate([0,0,-1])

cylinder(r=6, h=5);

}}

// Face spline coupling

rotate([0, 0, $t*360])

{

translate([0, 0, -3])

facespline();

translate([0, 0, 3])

rotate([0, 180, 360/2/n])

facespline();

}

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

I was curious what this looks like so I loaded it up and hit F6. I get No Geometry to Render.
-Bob
> On Sep 19, 2024, at 15:37, Caddiy via Discuss <discuss@lists.openscad.org> wrote:
>
> Something else with teeth that the world has been waiting for: a face spline coupling aka Hirth coupling. I created it some time ago as part of a design, but it had a glitch that turned out to be because the circumference of a small sector of a circle is slightly longer than the straight line across it. This left tiny but visible gaps between the splines.
>
> I thought it would be difficult to parametrise but it was not.
>
> But it still has some sharp edges that need rounding. Any volunteers?
>
> $fn=100;
>
> $vpr=[ 60, 0, 315 ];
>
> $vpt=[ 0, 0, 0 ];
>
> $vpd=80;
>
> /*
>
> */
>
> a=60; // Base angle
>
> r=12; // Radius
>
> n=24; // Number of splines
>
> module facespline()
>
> {
>
> difference()
>
> {
>
> intersection()
>
> {
>
> for(i = [1 : n])
>
> rotate(i * 360/n)
>
> polyhedron(
>
> points = [
>
> // Point 0
>
> [0, 0, PI*r/2/n*tan(a)],
>
> // Point 1
>
> [r, r*tan(360/2/n), 0],
>
> // Point 2
>
> [r, -r*tan(360/2/n), 0],
>
> // Point 3
>
> [r, 0, PI*r/n*tan(a)],
>
> // Point 4
>
> [0, 0, 0]
>
> ],
>
> faces = [
>
> [1,2,3],
>
> //[0,2,1],
>
> [3,2,0],
>
> [3,0,1],
>
> [0,2,4], //
>
> [0,4,1], //
>
> [1,4,2] //
>
> ]);
>
> cylinder(r=r, h=PI*r/16*tan(a)+1);
>
> }
>
> // Hole
>
> translate([0,0,-1])
>
> cylinder(r=6, h=5);
>
> }}
>
> // Face spline coupling
>
> rotate([0, 0, $t*360])
>
> {
>
> translate([0, 0, -3])
>
> facespline();
>
> translate([0, 0, 3])
>
> rotate([0, 180, 360/2/n])
>
> facespline();
>
> }
>
> _______________________________________________
> OpenSCAD mailing list
> To unsubscribe send an email to discuss-leave@lists.openscad.org

DP

Dan Perry

Thu, Sep 19, 2024 11:51 PM

Me too.

On Thu, Sep 19, 2024 at 4:40 PM Bob Carlson via Discuss <

discuss@lists.openscad.org> wrote:

I was curious what this looks like so I loaded it up and hit F6. I get No

Geometry to Render.

-Bob

On Sep 19, 2024, at 15:37, Caddiy via Discuss discuss@lists.openscad.org

wrote:

Something else with teeth that the world has been waiting for: a face

spline coupling aka Hirth coupling. I created it some time ago as part of a

design, but it had a glitch that turned out to be because the circumference

of a small sector of a circle is slightly longer than the straight line

across it. This left tiny but visible gaps between the splines.

I thought it would be difficult to parametrise but it was not.

But it still has some sharp edges that need rounding. Any volunteers?

$fn=100;

$vpr=[ 60, 0, 315 ];

$vpt=[ 0, 0, 0 ];

$vpd=80;

/*

*/

a=60; // Base angle

r=12; // Radius

n=24; // Number of splines

module facespline()

{

difference()

{

intersection()

{

for(i = [1 : n])

rotate(i * 360/n)

polyhedron(

points = [

// Point 0

[0, 0, PI*r/2/n*tan(a)],

// Point 1

[r, r*tan(360/2/n), 0],

// Point 2

[r, -r*tan(360/2/n), 0],

// Point 3

[r, 0, PI*r/n*tan(a)],

// Point 4

[0, 0, 0]

],

faces = [

[1,2,3],

//[0,2,1],

[3,2,0],

[3,0,1],

[0,2,4], //

[0,4,1], //

[1,4,2] //

]);

cylinder(r=r, h=PI*r/16*tan(a)+1);

}

// Hole

translate([0,0,-1])

cylinder(r=6, h=5);

}}

// Face spline coupling

rotate([0, 0, $t*360])

{

translate([0, 0, -3])

facespline();

translate([0, 0, 3])

rotate([0, 180, 360/2/n])

facespline();

}

OpenSCAD mailing list

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

OpenSCAD mailing list

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

Me too.
On Thu, Sep 19, 2024 at 4:40 PM Bob Carlson via Discuss <
discuss@lists.openscad.org> wrote:
> I was curious what this looks like so I loaded it up and hit F6. I get No
> Geometry to Render.
>
> -Bob
>
> On Sep 19, 2024, at 15:37, Caddiy via Discuss <discuss@lists.openscad.org>
> wrote:
>
> Something else with teeth that the world has been waiting for: a face
> spline coupling aka Hirth coupling. I created it some time ago as part of a
> design, but it had a glitch that turned out to be because the circumference
> of a small sector of a circle is slightly longer than the straight line
> across it. This left tiny but visible gaps between the splines.
>
> I thought it would be difficult to parametrise but it was not.
>
> But it still has some sharp edges that need rounding. Any volunteers?
>
> $fn=100;
>
> $vpr=[ 60, 0, 315 ];
>
> $vpt=[ 0, 0, 0 ];
>
> $vpd=80;
>
> /*
>
> */
>
> a=60; // Base angle
>
> r=12; // Radius
>
> n=24; // Number of splines
>
> module facespline()
>
> {
>
> difference()
>
> {
>
> intersection()
>
> {
>
> for(i = [1 : n])
>
> rotate(i * 360/n)
>
> polyhedron(
>
> points = [
>
> // Point 0
>
> [0, 0, PI*r/2/n*tan(a)],
>
> // Point 1
>
> [r, r*tan(360/2/n), 0],
>
> // Point 2
>
> [r, -r*tan(360/2/n), 0],
>
> // Point 3
>
> [r, 0, PI*r/n*tan(a)],
>
> // Point 4
>
> [0, 0, 0]
>
> ],
>
> faces = [
>
> [1,2,3],
>
> //[0,2,1],
>
> [3,2,0],
>
> [3,0,1],
>
> [0,2,4], //
>
> [0,4,1], //
>
> [1,4,2] //
>
> ]);
>
> cylinder(r=r, h=PI*r/16*tan(a)+1);
>
> }
>
> // Hole
>
> translate([0,0,-1])
>
> cylinder(r=6, h=5);
>
> }}
>
> // Face spline coupling
>
> rotate([0, 0, $t*360])
>
> {
>
> translate([0, 0, -3])
>
> facespline();
>
> translate([0, 0, 3])
>
> rotate([0, 180, 360/2/n])
>
> facespline();
>
> }
> _______________________________________________
> OpenSCAD mailing list
> To unsubscribe send an email to discuss-leave@lists.openscad.org
>
>
> _______________________________________________
> OpenSCAD mailing list
> To unsubscribe send an email to discuss-leave@lists.openscad.org
>

M

mikeonenine@web.de

Thu, Sep 19, 2024 11:55 PM

Works perfectly here.

Previews immediately with the cube-and-chevron icon, took a little longer with F6.

Works perfectly here.
Previews immediately with the cube-and-chevron icon, took a little longer with F6.

BC

Bob Carlson

Fri, Sep 20, 2024 12:13 AM

I am on a relatively recent snapshot. Are you using the (ancient) “released” version? Or maybe a more recent snapshot?

On Sep 19, 2024, at 16:55, Caddiy via Discuss discuss@lists.openscad.org wrote:

Works perfectly here.

Previews immediately with the cube-and-chevron icon, took a little longer with F6.

OpenSCAD mailing list

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

I am on a relatively recent snapshot. Are you using the (ancient) “released” version? Or maybe a more recent snapshot?
> On Sep 19, 2024, at 16:55, Caddiy via Discuss <discuss@lists.openscad.org> wrote:
>
> Works perfectly here.
>
> Previews immediately with the cube-and-chevron icon, took a little longer with F6.
>
> _______________________________________________
> OpenSCAD mailing list
> To unsubscribe send an email to discuss-leave@lists.openscad.org

M

mikeonenine@web.de

Fri, Sep 20, 2024 12:15 AM

This is what you should see.

BTW I said sector above, but meant segment.

This is what you should see.
BTW I said sector above, but meant segment.

M

mikeonenine@web.de

Fri, Sep 20, 2024 12:20 AM

I am on a relatively recent snapshot. Are you using the (ancient) “released” version? Or maybe a more recent snapshot?

On Sep 19, 2024, at 16:55, Caddiy via Discuss discuss@lists.openscad.org wrote:

Works perfectly here.

Previews immediately with the cube-and-chevron icon, took a little longer with F6.

OpenSCAD mailing list

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

i Am using Version 2021.01, but that shouldn’t make any difference?

> I am on a relatively recent snapshot. Are you using the (ancient) “released” version? Or maybe a more recent snapshot?
>
> On Sep 19, 2024, at 16:55, Caddiy via Discuss [discuss@lists.openscad.org](mailto:discuss@lists.openscad.org) wrote:
>
> Works perfectly here.
>
> Previews immediately with the cube-and-chevron icon, took a little longer with F6.
>
> ---
>
> > OpenSCAD mailing list \
> > To unsubscribe send an email to [discuss-leave@lists.openscad.org](mailto:discuss-leave@lists.openscad.org)
i Am using Version 2021.01, but that shouldn’t make any difference?

M

mikeonenine@web.de

Fri, Sep 20, 2024 12:37 AM

Still no joy?

Try deleting all //, /* and */.

Still no joy?
Try deleting all //, /\* and \*/.

K

Ken

Fri, Sep 20, 2024 12:50 AM

I tried that, still no joy. I'm running 2024.08.30

F5 says Compile & preview finished, total rendering time 0.064 seconds- but there's nothing there.

F6 says there is no top-level geometry to render.

On 2024-09-20 10:37, Caddiy via Discuss wrote:

Still no joy?

Try deleting all //, /* and */.

OpenSCAD mailing list

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

Cheers, Ken

bats059@gmail.com

https://vk7krj.com

https://vk7krj.com/running.html

A baby can be defined as an ego with a noise at one end and a smell at the other.

Your job as parents is to teach them to control all three.

My job as a grandad is to tell you how you are doing it all wrong!

I tried that, still no joy. I'm running 2024.08.30
F5 says Compile & preview finished, total rendering time 0.064 seconds- but there's nothing there.
F6 says there is no top-level geometry to render.
On 2024-09-20 10:37, Caddiy via Discuss wrote:
>
> Still no joy?
>
> Try deleting all //, /* and */.
>
>
> _______________________________________________
> OpenSCAD mailing list
> To unsubscribe send an email todiscuss-leave@lists.openscad.org
--
Cheers, Ken
bats059@gmail.com
https://vk7krj.com
https://vk7krj.com/running.html
----------------------------------------
A baby can be defined as an ego with a noise at one end and a smell at the other.
Your job as parents is to teach them to control all three.
My job as a grandad is to tell you how you are doing it all wrong!

M

mikeonenine@web.de

Fri, Sep 20, 2024 1:07 AM

`$fn=100;`

`$vpr=[ 60, 0, 315 ];`

`$vpt=[ 0, 0, 0 ];`

`$vpd=80;`

`a=60; // Base angle`

`r=12; // Radius`

`n=16; // Number of splines`

`module facespline()`

`{`

`difference()`

`{`

`intersection()`

`{`

`for(i = [1 : n])`

`rotate(i * 360/n)`

`polyhedron(`

`points = [`

`[0, 0, PI*r/2/n*tan(a)],`

`[r, r*tan(360/2/n), 0],`

`[r, -r*tan(360/2/n), 0],`

`[r, 0, PI*r/n*tan(a)],`

`[0, 0, 0]`

`],`

`faces = [`

`[1,2,3],`

`[3,2,0],`

`[3,0,1],`

`[0,2,4], `

`[0,4,1], `

`[1,4,2] `

`]);`

`cylinder(r=r, h=PI*r/16*tan(a)+1);`

`}`

`// Hole`

`translate([0,0,-1])`

`cylinder(r=6, h=5);`

`}}`

`// Face spline coupling`

`{`

`translate([0, 0, -3])`

`facespline();`

`translate([0, 0, 3])`

`rotate([0, 180, 360/2/n])`

`facespline();`

`}`

##### Does this work for you?
###### `$fn=100;`
`$vpr=[ 60, 0, 315 ];`
`$vpt=[ 0, 0, 0 ];`
`$vpd=80;`
`a=60; // Base angle`
`r=12; // Radius`
`n=16; // Number of splines`
`module facespline()`
`{`
`difference()`
`{`
`intersection()`
`{`
`for(i = [1 : n])`
`rotate(i * 360/n)`
`polyhedron(`
`points = [`
`[0, 0, PI*r/2/n*tan(a)],`
`[r, r*tan(360/2/n), 0],`
`[r, -r*tan(360/2/n), 0],`
`[r, 0, PI*r/n*tan(a)],`
`[0, 0, 0]`
`],`
`faces = [`
`[1,2,3],`
`[3,2,0],`
`[3,0,1],`
`[0,2,4], `
`[0,4,1], `
`[1,4,2] `
`]);`
`cylinder(r=r, h=PI*r/16*tan(a)+1);`
`}`
`// Hole`
`translate([0,0,-1])`
`cylinder(r=6, h=5);`
`}}`
`// Face spline coupling`
`{`
`translate([0, 0, -3])`
`facespline();`
`translate([0, 0, 3])`
`rotate([0, 180, 360/2/n])`
`facespline();`
`}`

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