Reducing all outside dimensions of an object

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Reducing all outside dimensions of an object

Robert H. Morrison
Hi All,

I want to be able to have some object e.g. let's use a large letter 'O' as an example.
I have some other object such as http://www.thingiverse.com/thing:1050 and I want to print the raised portion in a different color.  So I use the object minus the raised portion and subtract out my object (the letter 'O') and then I want to print out a reduced version of the object (in a different color) such that it easily fits in the embossed area created by subtracting the object from the plain business card holder.

I can not use scale because then the inner area would be smaller than that left in the embossed area and would not fit!

What I need is a function that reduces all outer perimters by 0.05 (or 0.1) mm so when printed it fits easily in the depression left for it.

Does anyone have any bright ideas?
 
Best regards,

Bob Morrison
BSEE, 78, Ga Tech

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Re: Reducing all outside dimensions of an object

Giles Bathgate-2
Openscad doesn't support an offsetting (or insetting) module as yet,
but some have managed to achieve the required effect using minkowski
to "grow" the part by a known amount, and then subtract the shape that
doesn't have minkowski applied.

Have a look through the mailing list for some examples. (unless
someone else would like to provide a repeat example in this thread)

Regards

Giles.

On 14 August 2012 13:32, Robert H. Morrison <[hidden email]> wrote:

> Hi All,
>
> I want to be able to have some object e.g. let's use a large letter 'O' as
> an example.
> I have some other object such as http://www.thingiverse.com/thing:1050 and I
> want to print the raised portion in a different color.  So I use the object
> minus the raised portion and subtract out my object (the letter 'O') and
> then I want to print out a reduced version of the object (in a different
> color) such that it easily fits in the embossed area created by subtracting
> the object from the plain business card holder.
>
> I can not use scale because then the inner area would be smaller than that
> left in the embossed area and would not fit!
>
> What I need is a function that reduces all outer perimters by 0.05 (or 0.1)
> mm so when printed it fits easily in the depression left for it.
>
> Does anyone have any bright ideas?
>
> Best regards,
>
> Bob Morrison
> BSEE, 78, Ga Tech
>
> _______________________________________________
> OpenSCAD mailing list
> [hidden email]
> http://rocklinux.net/mailman/listinfo/openscad
> http://openscad.org - https://flattr.com/thing/121566

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Re: Reducing all outside dimensions of an object

Robert H. Morrison
Hi Giles,

Thanks, the Minkowski function does exactly what I need!
Subtracting the original shape is not needed for my purpose.
 
Best regards,
   __            _ _ _
  /  )      /   ' ) ) )
 /--<  ____/_    / / / __,_  __  o _   ________
/___/_(_) /_)   / ' (_(_) (_/ (_<_/_)_(_) / / <_
                                 ,,,
                               (o o)
--- --- --- --- --- --- ---oOo--(_)--oOo--- --- --- --- --- --- ---
                       "Luke, use the source!"
--- --- --- --- --- --- ---oOo-------oOo--- --- --- --- --- --- ---

Bob Morrison
BSEE, 78, Ga Tech



From: Giles Bathgate <[hidden email]>
To: Robert H. Morrison <[hidden email]>; [hidden email]
Sent: Tuesday, August 14, 2012 2:36 PM
Subject: Re: [OpenSCAD] Reducing all outside dimensions of an object

Openscad doesn't support an offsetting (or insetting) module as yet,
but some have managed to achieve the required effect using minkowski
to "grow" the part by a known amount, and then subtract the shape that
doesn't have minkowski applied.

Have a look through the mailing list for some examples. (unless
someone else would like to provide a repeat example in this thread)

Regards

Giles.