Question for OpenScad users.

Have questions or comments about Simplify3D, Slic3r, Cura, Reptier, etc? Or wondering about which CAD software to use...discuss it here...
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Jules
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Question for OpenScad users.

Post by Jules » Tue Feb 23, 2016 12:42 am

Can you import or open an .STL or .STEP file in OpenScad to make modifications to it? :?:

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ednisley
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Re: Question for OpenScad users.

Post by ednisley » Tue Feb 23, 2016 1:11 am

Jules wrote:Can you import or open an .STL or .STEP file in OpenScad to make modifications to it? :?:
STL, yes. STEP, no.

https://en.wikibooks.org/wiki/OpenSCAD_ ... try#import

STL files must be manifold, not too complicated, and generally well-behaved. The only way to find out whether a specific file will work is to import it and see what happens; if OpenSCAD crashes, the file probably has problems. More recent OpenSCAD versions produce more happiness.

OpenSCAD doesn't automagically reposition the STL coordinates, so the object may wind up way off in the bushes and require a Easter Egg hunt. I consider that a fault of the model, not OpenSCAD: it's putting the model exactly where you told it do.

There's no mechanism for "reading" coordinates from an STL file, so you can't reposition an arbitrary object at (say) the origin without feeding in the coordinates by hand. That's also not a fault of OpenSCAD, because it's intended to create models, not edit them; there's been some effort to add that feature, but it's not ready for prime time.

Also, STL files don't carry units with them and OpenSCAD doesn't use units, so 1 STL unit = 1 OpenSCAD unit. Exporting an STL file intended to be a 1 inch cube will produce a 1 unit OpenSCAD cube, which may be much smaller than you expect.

I created Tux chocolate molds by importing STL files, although the tonnage of code may be off-putting:
http://softsolder.com/2014/04/04/chocol ... -silicone/

Image

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Jules
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Re: Question for OpenScad users.

Post by Jules » Tue Feb 23, 2016 1:39 am

Muchas Gracias! I got thrown off by the fact that it doesn't list those as an import option in the drop down, but I'll give it a try. :D

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Jules
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Re: Question for OpenScad users.

Post by Jules » Tue Feb 23, 2016 2:01 am

Hot damn! There it is! (Had to double up the backslashes as a Windows user, but it's in there! Thanks Ed! :D

jsc
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Re: Question for OpenScad users.

Post by jsc » Tue Feb 23, 2016 5:17 am

Whatcha doing, Jules?

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Jules
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Re: Question for OpenScad users.

Post by Jules » Tue Feb 23, 2016 6:20 am

Oh, just playing with OpenSCAD....Been meaning to take a look at it for a while and had a few minutes to install it today. (Big learning curve ahead......that has got to be the longest language definition page I've ever seen. :shock: )

:lol:

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ednisley
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Re: Question for OpenScad users.

Post by ednisley » Tue Feb 23, 2016 2:15 pm

Jules wrote:the longest language definition page
The presentation I did at the CNC Workshop in Detroit last year might be helpful:

http://softsolder.com/2015/06/18/cnc-wo ... -openscad/

No patter in the PDF, but the step-by-step code, pix, and linkies should help point out the most useful features...

The OpenSCAD mailing list has a very high signal-to-noise ratio, plus you can watch discussions between folks who live solid geometry and can say "affine transform" with a straight face:

Archive: http://forum.openscad.org/
Signup: http://lists.openscad.org/mailman/listi ... enscad.org

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sthone
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Re: Question for OpenScad users.

Post by sthone » Tue Feb 23, 2016 4:54 pm

Jules wrote:Oh, just playing with OpenSCAD....Been meaning to take a look at it for a while and had a few minutes to install it today. (Big learning curve ahead......that has got to be the longest language definition page I've ever seen. :shock: )

:lol:
Jules, did you give up on Solidworks already or are you trying to learning several CAD programs at once? :lol:
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Jules
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Re: Question for OpenScad users.

Post by Jules » Tue Feb 23, 2016 4:54 pm

Aces! :D Thanks Ed, I've bookmarked them for leisurely viewing!

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Jules
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Re: Question for OpenScad users.

Post by Jules » Tue Feb 23, 2016 5:11 pm

sthone wrote:...Jules, did you give up on Solidworks already or are you trying to learning several CAD programs at once? :lol:
Did a preliminary review of Solidworks, and I don't think it's going to be able to do what I need it to do. I guess that for the things I'm designing, (which tend to be more organic and less mechanical), Rhino works a little bit better, so for initial design, that one is probably the one I'll mainly use. (I've just got the SW Student version - maybe it does more if you get the whole works.)

What I'm still looking for, and haven't found yet, is one that has a kick-ass mesh modification function. I have used the freebie netfabb, and it does a good job of fixing unseen problems, but you really don't get much control over it, and i don't always like the results they come up with. They might print, but they're not always what I intended.

So far, the only mesh mod I can do is in Rhino, and it's extremely limited. (Simple shapes, not too complex a structure, tends to crash a lot!) I had hoped that by going to more of a CAD program I might find something that works a bit better. (And it's always good to keep learning - I can see some good uses for CAD designing down the road, when accuracy counts.)

So yeah, I guess I am trying to learn multiple CAD programs silmultaneously! (Love to do things the hard way!) :lol:

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