Empathy List Archives

C

cacb

Fri, Feb 20, 2015 12:09 PM

Hi, this is my first post. My name is Carsten Arnholm. My background is among
other things C++ programming using geometry kernels like ACIS. So I have
some understanding of the basics of boolean operations, although it is some
years back.

I am learning OpenSCAD now and find it a fantastic tool. Well done,
congratulations!

I have read some tutorials, watched YouTube videos and now I am trying to
make my first design using one of the latest snapshot releases of OpenSCAD.

This is my result so far
http://arnholm.org/tmp/openscad/mold_attempt1.png

Made with this code
http://arnholm.org/tmp/openscad/mold_attempt1.scad
(suggested improvements very welcome!)

I have 2 basic questions/comments

rotate_extrude

The rotate_extrude command seems broken

a) The rotation axis is unspecified, from drawings only you can infer it to
be z-axis

b) if you assume rotation axis is z-axis and then rotate the profile into
x-z plane, the extrusion fails to give a meaningful result (only a planar
disc). By guessing that The extrusion contained an implicit/undocumented
rotation into X-z plane, I was able to obtain the result I was looking for.
But this is not correct behaviour I think.

c) There is no way to rotate anything less than 360 degrees. A major
limitation. You have to make a full rotation and then cut away the rest
later using difference(), which is not optimal.

Tongue/groove

The part shown is supposed to be a 10 degree "cake slice". By printing 36
copies on a 3d printer you would get a full 360 degree mold by gluing them
together. To make it strong it would be most useful to include a
tongue/groove connection (groove on one side of the part, tongue on the
other). However, I really don't see yet how to do that with OpenSCAD. Any
suggestions?

Please understand that I am really enthusiastic about OpenSCAD and don't
mean to be critical, basically trying to learn.

--
View this message in context: http://forum.openscad.org/questions-on-rotate-extrude-tp11674.html
Sent from the OpenSCAD mailing list archive at Nabble.com.

Hi, this is my first post. My name is Carsten Arnholm. My background is among other things C++ programming using geometry kernels like ACIS. So I have some understanding of the basics of boolean operations, although it is some years back. I am learning OpenSCAD now and find it a fantastic tool. Well done, congratulations! I have read some tutorials, watched YouTube videos and now I am trying to make my first design using one of the latest snapshot releases of OpenSCAD. This is my result so far http://arnholm.org/tmp/openscad/mold_attempt1.png Made with this code http://arnholm.org/tmp/openscad/mold_attempt1.scad (suggested improvements very welcome!) I have 2 basic questions/comments 1. rotate_extrude ------------------- The rotate_extrude command seems broken a) The rotation axis is unspecified, from drawings only you can infer it to be z-axis b) if you assume rotation axis is z-axis and then rotate the profile into x-z plane, the extrusion fails to give a meaningful result (only a planar disc). By guessing that The extrusion contained an implicit/undocumented rotation into X-z plane, I was able to obtain the result I was looking for. But this is not correct behaviour I think. c) There is no way to rotate anything less than 360 degrees. A major limitation. You have to make a full rotation and then cut away the rest later using difference(), which is not optimal. 2. Tongue/groove -------------------- The part shown is supposed to be a 10 degree "cake slice". By printing 36 copies on a 3d printer you would get a full 360 degree mold by gluing them together. To make it strong it would be most useful to include a tongue/groove connection (groove on one side of the part, tongue on the other). However, I really don't see yet how to do that with OpenSCAD. Any suggestions? Please understand that I am really enthusiastic about OpenSCAD and don't mean to be critical, basically trying to learn. -- View this message in context: http://forum.openscad.org/questions-on-rotate-extrude-tp11674.html Sent from the OpenSCAD mailing list archive at Nabble.com.

C

clothbot

Fri, Feb 20, 2015 2:15 PM

Re. rotate_extrude by an angle less than 360, I filed Issue #1191 not too
long back to capture+track this frequently requested feature:

https://github.com/openscad/openscad/issues/1191

Andrew.

--
View this message in context: http://forum.openscad.org/questions-on-rotate-extrude-tp11674p11675.html
Sent from the OpenSCAD mailing list archive at Nabble.com.

Re. rotate_extrude by an angle less than 360, I filed Issue #1191 not too long back to capture+track this frequently requested feature: https://github.com/openscad/openscad/issues/1191 Andrew. -- View this message in context: http://forum.openscad.org/questions-on-rotate-extrude-tp11674p11675.html Sent from the OpenSCAD mailing list archive at Nabble.com.

PF

Peter Falke

Fri, Feb 20, 2015 3:20 PM

Try searching thingiverse:
http://www.thingiverse.com/search/page:5?q=connector+openscad&sa=

Maybe http://www.thingiverse.com/thing:10701

2015-02-20 15:15 GMT+01:00 clothbot andrew@plumb.org:

Re. rotate_extrude by an angle less than 360, I filed Issue #1191 not too
long back to capture+track this frequently requested feature:

https://github.com/openscad/openscad/issues/1191

Andrew.

--
View this message in context:
http://forum.openscad.org/questions-on-rotate-extrude-tp11674p11675.html
Sent from the OpenSCAD mailing list archive at Nabble.com.

OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org

--
stempeldergeschichte@googlemail.com karsten@rohrbach.de

P.S. Falls meine E-Mail kürzer ausfällt als Dir angenehm ist:
Ich probiere gerade aus kurze Antworten statt gar keine Antworten zu
schreiben.
Wenn Du gerne mehr lesen möchtest, dann lass es mich bitte wissen.

P.S. In case my e-mail is shorter than you enjoy:
I am currently trying short replies instead of no replies at all.
Please let me know, if you like to read more.

Enjoy!

Try searching thingiverse: http://www.thingiverse.com/search/page:5?q=connector+openscad&sa= Maybe http://www.thingiverse.com/thing:10701 2015-02-20 15:15 GMT+01:00 clothbot <andrew@plumb.org>: > Re. rotate_extrude by an angle less than 360, I filed Issue #1191 not too > long back to capture+track this frequently requested feature: > > https://github.com/openscad/openscad/issues/1191 > > Andrew. > > > > > -- > View this message in context: > http://forum.openscad.org/questions-on-rotate-extrude-tp11674p11675.html > Sent from the OpenSCAD mailing list archive at Nabble.com. > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org > -- stempeldergeschichte@googlemail.com <karsten@rohrbach.de> P.S. Falls meine E-Mail kürzer ausfällt als Dir angenehm ist: Ich probiere gerade aus kurze Antworten statt gar keine Antworten zu schreiben. Wenn Du gerne mehr lesen möchtest, dann lass es mich bitte wissen. P.S. In case my e-mail is shorter than you enjoy: I am currently trying short replies instead of no replies at all. Please let me know, if you like to read more. Enjoy!

R

robnee

Fri, Feb 20, 2015 5:11 PM

I'm willing to contribute to the bounty on this feature. How much will it
take to get it done?

--
View this message in context: http://forum.openscad.org/questions-on-rotate-extrude-tp11674p11677.html
Sent from the OpenSCAD mailing list archive at Nabble.com.

I'm willing to contribute to the bounty on this feature. How much will it take to get it done? -- View this message in context: http://forum.openscad.org/questions-on-rotate-extrude-tp11674p11677.html Sent from the OpenSCAD mailing list archive at Nabble.com.

C

cacb

Fri, Feb 20, 2015 6:39 PM

@Andrew: Thank you, that is good to know, I can imagine it is a frequent
request.

I didn't see how to proceed with attempt1, so I tried again in a different
way. The first attempt appeared to show it was difficult to describe the
concave corner blend (therefore I faked it). That means the model wasn't
really parametric anymore anyway. So instead I redesigned the 2D profile in
LibreCAD http://librecad.org and then imported that it into OpenSCAD via
DXF (R12). This seems to be easier (I didn't know LibreCAD either).

From LibreCAD

Basic profile: http://arnholm.org/tmp/openscad/mold_profile_R12.dxf
With "tongue": http://arnholm.org/tmp/openscad/mold_tongue_R12.dxf

With that I was able to proceed in OpenSCAD
http://arnholm.org/tmp/openscad/mold_attempt2.scad
http://arnholm.org/tmp/openscad/g3d.scad

The files show how I worked around the missing angle parameter in
rotate_extrude. It kind of worked, but a proper implementation in OpenSCAD
is clearly to be preferred.

A couple if images of the result
http://arnholm.org/tmp/openscad/mold_attempt2_2.png
http://arnholm.org/tmp/openscad/mold_attempt2_stlC.png
This is clearly closer to the original design idea.

I could not find anything like that on Thingiverse (which does not mean it
does not exist...).

--
View this message in context: http://forum.openscad.org/questions-on-rotate-extrude-tp11674p11679.html
Sent from the OpenSCAD mailing list archive at Nabble.com.

@Andrew: Thank you, that is good to know, I can imagine it is a frequent request. I didn't see how to proceed with attempt1, so I tried again in a different way. The first attempt appeared to show it was difficult to describe the concave corner blend (therefore I faked it). That means the model wasn't really parametric anymore anyway. So instead I redesigned the 2D profile in LibreCAD <http://librecad.org> and then imported that it into OpenSCAD via DXF (R12). This seems to be easier (I didn't know LibreCAD either). >From LibreCAD Basic profile: http://arnholm.org/tmp/openscad/mold_profile_R12.dxf With "tongue": http://arnholm.org/tmp/openscad/mold_tongue_R12.dxf With that I was able to proceed in OpenSCAD http://arnholm.org/tmp/openscad/mold_attempt2.scad http://arnholm.org/tmp/openscad/g3d.scad The files show how I worked around the missing angle parameter in rotate_extrude. It kind of worked, but a proper implementation in OpenSCAD is clearly to be preferred. A couple if images of the result http://arnholm.org/tmp/openscad/mold_attempt2_2.png http://arnholm.org/tmp/openscad/mold_attempt2_stlC.png This is clearly closer to the original design idea. I could not find anything like that on Thingiverse (which does not mean it does not exist...). -- View this message in context: http://forum.openscad.org/questions-on-rotate-extrude-tp11674p11679.html Sent from the OpenSCAD mailing list archive at Nabble.com.

discuss@lists.openscad.org

questions on rotate_extrude