### Re: Tangential join/infill two parallel vertical cylindrical tubes.

A
Wed, Apr 21, 2021 10:22 AM

If your model can be made as an extrusion of something 2d then that will be
faster than making it in 3d, and you can difference() circles without any
problem.  But in 3d if you subtract a cylinder from another cylinder and
they are the same length then OpenSCAD will get confused about the surface
and you will see a phantom surface at the ends.  Never subtract two 3d
objects that share a face.

As you say extruding a polygon on a plane has no issues with holes fully
cutting and where the cylinders are the same height with no vertical
offset
that's trivial too (I just add "2" to the length).  The problem with the
hole lengths comes in when using hull to fill in the space between the
cylinders and the  cylinders are either different lengths, vertically
offset or both so that there are sloping sections between the two
cylinders
meaning the holes are cutting through a sloping face so need to be longer
than their "parent" cylinder.
Chris Johnson

To unsubscribe send an email to

If your model can be made as an extrusion of something 2d then that will be faster than making it in 3d, and you can difference() circles without any problem. But in 3d if you subtract a cylinder from another cylinder and they are the same length then OpenSCAD will get confused about the surface and you will see a phantom surface at the ends. Never subtract two 3d objects that share a face. OpenSCAD mailing list-2 wrote > As you say extruding a polygon on a plane has no issues with holes fully > cutting and where the cylinders are the same height with no vertical > offset > that's trivial too (I just add "2" to the length). The problem with the > hole lengths comes in when using hull to fill in the space between the > cylinders and the cylinders are either different lengths, vertically > offset or both so that there are sloping sections between the two > cylinders > meaning the holes are cutting through a sloping face so need to be longer > than their "parent" cylinder. > Chris Johnson > > >> > > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to > discuss-leave@.openscad -- Sent from: http://forum.openscad.org/
RW
Ray West
Wed, Apr 21, 2021 2:55 PM

Is there a method of doing a linear-extrude or equivalent in the
opposite direction, (-ve z instead of +ve)? In simple 3 axis machining,
it is usual to have z0 at the top of the work piece, and it would make
things easier, I think, if an extrude in the -ve z direction was possible.

For example, instead of a  number of lines like
'translate([0,0,-5])linear_extrude(5)notch();'  could simply write
'linear_extrude(-5)notch;' It would allow a very quick way of getting
the 2d drawing into a 3d model of the object.

Is there a method of doing a linear-extrude or equivalent in the opposite direction, (-ve z instead of +ve)? In simple 3 axis machining, it is usual to have z0 at the top of the work piece, and it would make things easier, I think, if an extrude in the -ve z direction was possible. For example, instead of a  number of lines like 'translate([0,0,-5])linear_extrude(5)notch();'  could simply write 'linear_extrude(-5)notch;' It would allow a very quick way of getting the 2d drawing into a 3d model of the object.
AC
A. Craig West
Wed, Apr 21, 2021 3:03 PM

I would just use:
mirror([0, 0, 1]) linear_extrude...

On Wed, 21 Apr 2021, 10:55 Ray West, raywest@raywest.com wrote:

Is there a method of doing a linear-extrude or equivalent in the
opposite direction, (-ve z instead of +ve)? In simple 3 axis machining,
it is usual to have z0 at the top of the work piece, and it would make
things easier, I think, if an extrude in the -ve z direction was possible.

For example, instead of a  number of lines like
'translate([0,0,-5])linear_extrude(5)notch();'  could simply write
'linear_extrude(-5)notch;' It would allow a very quick way of getting
the 2d drawing into a 3d model of the object.

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

I would just use: mirror([0, 0, 1]) linear_extrude... On Wed, 21 Apr 2021, 10:55 Ray West, <raywest@raywest.com> wrote: > Is there a method of doing a linear-extrude or equivalent in the > opposite direction, (-ve z instead of +ve)? In simple 3 axis machining, > it is usual to have z0 at the top of the work piece, and it would make > things easier, I think, if an extrude in the -ve z direction was possible. > > For example, instead of a number of lines like > 'translate([0,0,-5])linear_extrude(5)notch();' could simply write > 'linear_extrude(-5)notch;' It would allow a very quick way of getting > the 2d drawing into a 3d model of the object. > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org >
GH
Gene Heskett
Wed, Apr 21, 2021 4:50 PM

On Wednesday 21 April 2021 11:03:52 A. Craig West wrote:

I would just use:
mirror([0, 0, 1]) linear_extrude...

Now, why didn't I think of that? Go ahead, answer that, I deserve it.

That would be an ideal first step in making gcode for a milliing machine.
The next would be a "slicer" like translator to break that depth into
something the machine is capable of. Just think, from an idea done in
openscad, sliced into gcode to drive the machine. The capabilities of
that, and the time saved in making the finished part are mind boggling.

On Wed, 21 Apr 2021, 10:55 Ray West, raywest@raywest.com wrote:

Is there a method of doing a linear-extrude or equivalent in the
opposite direction, (-ve z instead of +ve)? In simple 3 axis
machining, it is usual to have z0 at the top of the work piece, and
it would make things easier, I think, if an extrude in the -ve z
direction was possible.

For example, instead of a  number of lines like
'translate([0,0,-5])linear_extrude(5)notch();'  could simply write
'linear_extrude(-5)notch;' It would allow a very quick way of
getting the 2d drawing into a 3d model of the object.

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

## Cheers, Gene Heskett

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.

On Wednesday 21 April 2021 11:03:52 A. Craig West wrote: > I would just use: > mirror([0, 0, 1]) linear_extrude... Now, why didn't I think of that? Go ahead, answer that, I deserve it. That would be an ideal first step in making gcode for a milliing machine. The next would be a "slicer" like translator to break that depth into something the machine is capable of. Just think, from an idea done in openscad, sliced into gcode to drive the machine. The capabilities of that, and the time saved in making the finished part are mind boggling. > On Wed, 21 Apr 2021, 10:55 Ray West, <raywest@raywest.com> wrote: > > Is there a method of doing a linear-extrude or equivalent in the > > opposite direction, (-ve z instead of +ve)? In simple 3 axis > > machining, it is usual to have z0 at the top of the work piece, and > > it would make things easier, I think, if an extrude in the -ve z > > direction was possible. > > > > For example, instead of a number of lines like > > 'translate([0,0,-5])linear_extrude(5)notch();' could simply write > > 'linear_extrude(-5)notch;' It would allow a very quick way of > > getting the 2d drawing into a 3d model of the object. > > _______________________________________________ > > OpenSCAD mailing list > > To unsubscribe send an email to discuss-leave@lists.openscad.org Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene>
F
fred
Wed, Apr 21, 2021 5:14 PM

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Is OpenSCAD to CNC possible?. OpenSCAD has been a brilliant tool to indulge my design/construct. or just plain h...
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I found this thread that seems promising. There were other semi-related links when searching for "OpenSCAD to gcode converter" but none of them as promising as the above link. I'm not qualified to determine suitability.

``````On Wednesday, April 21, 2021, 12:51:00 PM EDT, Gene Heskett <gheskett@shentel.net> wrote:
``````

Now, why didn't I think of that? Go ahead, answer that, I deserve it.

That would be an ideal first step in making gcode for a milliing machine.
The next would be a "slicer" like translator to break that depth into
something the machine is capable of. Just think, from an idea done in
openscad, sliced into gcode to drive the machine. The capabilities of
that, and the time saved in making the finished part are mind boggling.

AC
A. Craig West
Wed, Apr 21, 2021 5:16 PM

Openscad is an amazingly flexible tool, but I do find that it is overly
limited by the assumption that 3d printers are the only possible use case.
I find that the language is great for expressing geometry in 2d as well,
but due to the assumption that all generated objects must have
thickness/volume, you can't actually use it for things like laser
cutting...

On Wed, 21 Apr 2021, 12:50 Gene Heskett, gheskett@shentel.net wrote:

On Wednesday 21 April 2021 11:03:52 A. Craig West wrote:

I would just use:
mirror([0, 0, 1]) linear_extrude...

Now, why didn't I think of that? Go ahead, answer that, I deserve it.

That would be an ideal first step in making gcode for a milliing machine.
The next would be a "slicer" like translator to break that depth into
something the machine is capable of. Just think, from an idea done in
openscad, sliced into gcode to drive the machine. The capabilities of
that, and the time saved in making the finished part are mind boggling.

On Wed, 21 Apr 2021, 10:55 Ray West, raywest@raywest.com wrote:

Is there a method of doing a linear-extrude or equivalent in the
opposite direction, (-ve z instead of +ve)? In simple 3 axis
machining, it is usual to have z0 at the top of the work piece, and
it would make things easier, I think, if an extrude in the -ve z
direction was possible.

For example, instead of a  number of lines like
'translate([0,0,-5])linear_extrude(5)notch();'  could simply write
'linear_extrude(-5)notch;' It would allow a very quick way of
getting the 2d drawing into a 3d model of the object.

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

## Cheers, Gene Heskett

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.

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

F
fred
Wed, Apr 21, 2021 5:32 PM

I've used OpenSCAD to create an object which I then "projected" to create the flat outline I needed to export to SVG, which is accepted by my laser cutting software. It was the most efficient method available to me at the time. There may have been other ways, but it worked for my purposes. I'll be doing a similar task for a boat hull, to create outlines to make on the laser a dry dock sort of array.

``````On Wednesday, April 21, 2021, 1:17:43 PM EDT, A. Craig West <acraigwest@gmail.com> wrote:
``````

Openscad is an amazingly flexible tool, but I do find that it is overly limited by the assumption that 3d printers are the only possible use case. I find that the language is great for expressing geometry in 2d as well, but due to the assumption that all generated objects must have thickness/volume, you can't actually use it for things like laser cutting...
On Wed, 21 Apr 2021, 12:50 Gene Heskett, gheskett@shentel.net wrote:

On Wednesday 21 April 2021 11:03:52 A. Craig West wrote:

I would just use:
mirror([0, 0, 1]) linear_extrude...

Now, why didn't I think of that? Go ahead, answer that, I deserve it.

That would be an ideal first step in making gcode for a milliing machine.
The next would be a "slicer" like translator to break that depth into
something the machine is capable of. Just think, from an idea done in
openscad, sliced into gcode to drive the machine. The capabilities of
that, and the time saved in making the finished part are mind boggling.

On Wed, 21 Apr 2021, 10:55 Ray West, raywest@raywest.com wrote:

Is there a method of doing a linear-extrude or equivalent in the
opposite direction, (-ve z instead of +ve)? In simple 3 axis
machining, it is usual to have z0 at the top of the work piece, and
it would make things easier, I think, if an extrude in the -ve z
direction was possible.

For example, instead of a  number of lines like
'translate([0,0,-5])linear_extrude(5)notch();'  could simply write
'linear_extrude(-5)notch;' It would allow a very quick way of
getting the 2d drawing into a 3d model of the object.

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

## Cheers, Gene Heskett

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
Genes Web page http://geneslinuxbox.net:6309/gene

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

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

AG
Alex Gibson
Wed, Apr 21, 2021 5:38 PM

I’m confused to read that as I use it all the time for 2D!

Are you aware of the whole 2D subsystem? IE square([1,2]); instead of cube([1,2,3]);?

And that you can both import and export DXF files which are good for laser cutting and CNC routing?

(if you want to import DXF files – you need to make sure they don’t contain curves as these come in many incompatible dialects – instead decimate them to many straight sections – there’s an excellent plugin for Inkscape called ‘DXF output for OpenSCAD’ or similar which does this for you)

You can take a 2D shape and linear or rotate extrude to 3D, or you can cut a cross section from a 3D model in 2D with projection()…

Or… what is it you’re struggling to do?

Cheers,

Alex Gibson

edumaker limited

·        Project management

·        Operations & Process improvement

·        3D Printing

From: A. Craig West [mailto:acraigwest@gmail.com]
Sent: 21 April 2021 18:17

Openscad is an amazingly flexible tool, but I do find that it is overly limited by the assumption that 3d printers are the only possible use case. I find that the language is great for expressing geometry in 2d as well, but due to the assumption that all generated objects must have thickness/volume, you can't actually use it for things like laser cutting...

On Wed, 21 Apr 2021, 12:50 Gene Heskett, gheskett@shentel.net wrote:

On Wednesday 21 April 2021 11:03:52 A. Craig West wrote:

I would just use:
mirror([0, 0, 1]) linear_extrude...

Now, why didn't I think of that? Go ahead, answer that, I deserve it.

That would be an ideal first step in making gcode for a milliing machine.
The next would be a "slicer" like translator to break that depth into
something the machine is capable of. Just think, from an idea done in
openscad, sliced into gcode to drive the machine. The capabilities of
that, and the time saved in making the finished part are mind boggling.

On Wed, 21 Apr 2021, 10:55 Ray West, raywest@raywest.com wrote:

Is there a method of doing a linear-extrude or equivalent in the
opposite direction, (-ve z instead of +ve)? In simple 3 axis
machining, it is usual to have z0 at the top of the work piece, and
it would make things easier, I think, if an extrude in the -ve z
direction was possible.

For example, instead of a  number of lines like
'translate([0,0,-5])linear_extrude(5)notch();'  could simply write
'linear_extrude(-5)notch;' It would allow a very quick way of
getting the 2d drawing into a 3d model of the object.

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

## Cheers, Gene Heskett

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.

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

AC
A. Craig West
Wed, Apr 21, 2021 5:44 PM

You can export in 2d, but you can't export open shapes, which can be a
problem for laser cutting, as to make a line cut, you run the laser over
the path twice

On Wed, 21 Apr 2021, 13:40 Alex Gibson, alex@alexgibson.net wrote:

I’m confused to read that as I use it all the time for 2D!

Are you aware of the whole 2D subsystem? IE square([1,2]); instead of
cube([1,2,3]);?

And that you can both import and export DXF files which are good for laser
cutting and CNC routing?

(if you want to import DXF files – you need to make sure they don’t
contain curves as these come in many incompatible dialects – instead
decimate them to many straight sections – there’s an excellent plugin for
Inkscape called ‘DXF output for OpenSCAD’ or similar which does this for
you)

You can take a 2D shape and linear or rotate extrude to 3D, or you can cut
a cross section from a 3D model in 2D with projection()…

Or… what is it you’re struggling to do?

Cheers,

Alex Gibson

edumaker limited

·        Project management

·        Operations & Process improvement

·        3D Printing

From: A. Craig West [mailto:acraigwest@gmail.com]
Sent: 21 April 2021 18:17

Openscad is an amazingly flexible tool, but I do find that it is overly
limited by the assumption that 3d printers are the only possible use case.
I find that the language is great for expressing geometry in 2d as well,
but due to the assumption that all generated objects must have
thickness/volume, you can't actually use it for things like laser
cutting...

On Wed, 21 Apr 2021, 12:50 Gene Heskett, gheskett@shentel.net wrote:

On Wednesday 21 April 2021 11:03:52 A. Craig West wrote:

I would just use:
mirror([0, 0, 1]) linear_extrude...

Now, why didn't I think of that? Go ahead, answer that, I deserve it.

That would be an ideal first step in making gcode for a milliing machine.
The next would be a "slicer" like translator to break that depth into
something the machine is capable of. Just think, from an idea done in
openscad, sliced into gcode to drive the machine. The capabilities of
that, and the time saved in making the finished part are mind boggling.

On Wed, 21 Apr 2021, 10:55 Ray West, raywest@raywest.com wrote:

Is there a method of doing a linear-extrude or equivalent in the
opposite direction, (-ve z instead of +ve)? In simple 3 axis
machining, it is usual to have z0 at the top of the work piece, and
it would make things easier, I think, if an extrude in the -ve z
direction was possible.

For example, instead of a  number of lines like
'translate([0,0,-5])linear_extrude(5)notch();'  could simply write
'linear_extrude(-5)notch;' It would allow a very quick way of
getting the 2d drawing into a 3d model of the object.

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

## Cheers, Gene Heskett

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.

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

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

AG
Alex Gibson
Wed, Apr 21, 2021 5:54 PM

Ah – I see.  Your problem is the lack of a 1D subsystem J

It’s never really crossed my mind as a significant constraint, despite using OpenSCAD for laser cutting plenty, but I think I’ve had the same problem and just fixed the consequences – for example importing the DXF into RDWorks/Lightburn and before laser cutting just deleting the unnecessary lines – or accept the unnecessary second cut.

I wonder how significant a structural change to the language it would be to actually add in the capability to OpenSCAD to draw a line… for example instead of square([1,2]); or cube([1,2,3]); you could have line([1]); which until rotated or translated always began along the X axis?  Could a valid DXF file be exported with that?

Cheers,

Alex Gibson

edumaker limited

·        Project management

·        Operations & Process improvement

·        3D Printing

From: A. Craig West [mailto:acraigwest@gmail.com]
Sent: 21 April 2021 18:44

You can export in 2d, but you can't export open shapes, which can be a problem for laser cutting, as to make a line cut, you run the laser over the path twice

On Wed, 21 Apr 2021, 13:40 Alex Gibson, alex@alexgibson.net wrote:

I’m confused to read that as I use it all the time for 2D!

Are you aware of the whole 2D subsystem? IE square([1,2]); instead of cube([1,2,3]);?

And that you can both import and export DXF files which are good for laser cutting and CNC routing?

(if you want to import DXF files – you need to make sure they don’t contain curves as these come in many incompatible dialects – instead decimate them to many straight sections – there’s an excellent plugin for Inkscape called ‘DXF output for OpenSCAD’ or similar which does this for you)

You can take a 2D shape and linear or rotate extrude to 3D, or you can cut a cross section from a 3D model in 2D with projection()…

Or… what is it you’re struggling to do?

Cheers,

Alex Gibson

edumaker limited

·        Project management

·        Operations & Process improvement

·        3D Printing

From: A. Craig West [mailto:acraigwest@gmail.com]
Sent: 21 April 2021 18:17

Openscad is an amazingly flexible tool, but I do find that it is overly limited by the assumption that 3d printers are the only possible use case. I find that the language is great for expressing geometry in 2d as well, but due to the assumption that all generated objects must have thickness/volume, you can't actually use it for things like laser cutting...

On Wed, 21 Apr 2021, 12:50 Gene Heskett, gheskett@shentel.net wrote:

On Wednesday 21 April 2021 11:03:52 A. Craig West wrote:

I would just use:
mirror([0, 0, 1]) linear_extrude...

Now, why didn't I think of that? Go ahead, answer that, I deserve it.

That would be an ideal first step in making gcode for a milliing machine.
The next would be a "slicer" like translator to break that depth into
something the machine is capable of. Just think, from an idea done in
openscad, sliced into gcode to drive the machine. The capabilities of
that, and the time saved in making the finished part are mind boggling.

On Wed, 21 Apr 2021, 10:55 Ray West, raywest@raywest.com wrote:

Is there a method of doing a linear-extrude or equivalent in the
opposite direction, (-ve z instead of +ve)? In simple 3 axis
machining, it is usual to have z0 at the top of the work piece, and
it would make things easier, I think, if an extrude in the -ve z
direction was possible.

For example, instead of a  number of lines like
'translate([0,0,-5])linear_extrude(5)notch();'  could simply write
'linear_extrude(-5)notch;' It would allow a very quick way of
getting the 2d drawing into a 3d model of the object.

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

## Cheers, Gene Heskett

"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author)
If we desire respect for the law, we must first make the law respectable.