Empathy List Archives

J

jordanthompson

Sun, Aug 23, 2020 3:12 PM

Hi all,
I am trying to wrap my head around this:
Since OpenScad doesn't support units, how do you print a correctly-sized
model? I am trying to make some feet for a food processor and they need to
fit into the 1/4 inch (sorry, its easier for me to think in inches) hole.

I am using Cura slicer and Repetier.

thanks in advance for your help

--
Sent from: http://forum.openscad.org/

Hi all, I am trying to wrap my head around this: Since OpenScad doesn't support units, how do you print a correctly-sized model? I am trying to make some feet for a food processor and they need to fit into the 1/4 inch (sorry, its easier for me to think in inches) hole. I am using Cura slicer and Repetier. thanks in advance for your help -- Sent from: http://forum.openscad.org/

WF

William F. Adams

Sun, Aug 23, 2020 3:17 PM

jordanthompson wrote:

Since OpenScad doesn't support units, how do you print a correctly-sized
model? I am trying to make some feet for a food processor and they need to
fit into the 1/4 inch (sorry, its easier for me to think in inches) hole.

I've just always assumed the measure in OpenSCAD was millimeters and exports have always matched up dimensionally on that basis --- should that not work?
So, 3.175 radius and 6.35 diameter (but see the discussions about making holes match based on orientation and so forth)
William

jordanthompson wrote: >Since OpenScad doesn't support units, how do you print a correctly-sized >model? I am trying to make some feet for a food processor and they need to >fit into the 1/4 inch (sorry, its easier for me to think in inches) hole. I've just always assumed the measure in OpenSCAD was millimeters and exports have always matched up dimensionally on that basis --- should that not work? So, 3.175 radius and 6.35 diameter (but see the discussions about making holes match based on orientation and so forth) William

NH

nop head

Sun, Aug 23, 2020 3:38 PM

Openscad is unitless, so whatever numbers you put in the scad file go into
the STL file. STL is also unitless but slicers default to interpreting the
numbers as mm.

On Sun, 23 Aug 2020 at 16:18, William F. Adams via Discuss <
discuss@lists.openscad.org> wrote:

jordanthompson wrote:

Since OpenScad doesn't support units, how do you print a correctly-sized
model? I am trying to make some feet for a food processor and they need

to

fit into the 1/4 inch (sorry, its easier for me to think in inches) hole.

I've just always assumed the measure in OpenSCAD was millimeters and
exports have always matched up dimensionally on that basis --- should that
not work?

So, 3.175 radius and 6.35 diameter (but see the discussions about making
holes match based on orientation and so forth)

William

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

Openscad is unitless, so whatever numbers you put in the scad file go into the STL file. STL is also unitless but slicers default to interpreting the numbers as mm. On Sun, 23 Aug 2020 at 16:18, William F. Adams via Discuss < discuss@lists.openscad.org> wrote: > jordanthompson wrote: > > >Since OpenScad doesn't support units, how do you print a correctly-sized > >model? I am trying to make some feet for a food processor and they need > to > >fit into the 1/4 inch (sorry, its easier for me to think in inches) hole. > > I've just always assumed the measure in OpenSCAD was millimeters and > exports have always matched up dimensionally on that basis --- should that > not work? > > So, 3.175 radius and 6.35 diameter (but see the discussions about making > holes match based on orientation and so forth) > > William > > > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >

M

MichaelAtOz

Mon, Aug 24, 2020 12:38 AM

You then have:

inch=25.4;
...
holeDiameter=0.25inch; // or =1/4inch if you prefer

IMHO better than trying to get your toolchain into imperial.

-----Original Message-----
From: Discuss [mailto:discuss-bounces@lists.openscad.org] On Behalf Of jordanthompson
Sent: Mon, 24 Aug 2020 01:12
To: discuss@lists.openscad.org
Subject: [OpenSCAD] scaling with OpenScad, Cura, and Repetier

Hi all,
I am trying to wrap my head around this:
Since OpenScad doesn't support units, how do you print a correctly-sized
model? I am trying to make some feet for a food processor and they need to
fit into the 1/4 inch (sorry, its easier for me to think in inches) hole.

I am using Cura slicer and Repetier.

thanks in advance for your help

--
Sent from: http://forum.openscad.org/

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

--
This email has been checked for viruses by AVG.
https://www.avg.com

You then have: inch=25.4; ... holeDiameter=0.25*inch; // or =1/4*inch if you prefer IMHO better than trying to get your toolchain into imperial. > -----Original Message----- > From: Discuss [mailto:discuss-bounces@lists.openscad.org] On Behalf Of jordanthompson > Sent: Mon, 24 Aug 2020 01:12 > To: discuss@lists.openscad.org > Subject: [OpenSCAD] scaling with OpenScad, Cura, and Repetier > > Hi all, > I am trying to wrap my head around this: > Since OpenScad doesn't support units, how do you print a correctly-sized > model? I am trying to make some feet for a food processor and they need to > fit into the 1/4 inch (sorry, its easier for me to think in inches) hole. > > I am using Cura slicer and Repetier. > > thanks in advance for your help > > > > -- > Sent from: http://forum.openscad.org/ > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org -- This email has been checked for viruses by AVG. https://www.avg.com

J

jordanthompson

Mon, Aug 24, 2020 2:44 PM

That is what I wound up doing but it surprised me that literally EVERYWHERE I
read, OpenScad was unit-less.
In fact (at least with Cura and Repetier on my modified Davinci 1.0a) 1 unit
= 1 mm. So to convert to inches:

2.54 in/cm *10 mm/cm = 25.4 mm/in

I now have:
2.54 * 10 = inches;

// 1/4 in sphere:
sphere(r=1/4*inches);

thanks for helping me clear this up!

--
Sent from: http://forum.openscad.org/

That is what I wound up doing but it surprised me that literally EVERYWHERE I read, OpenScad was unit-less. In fact (at least with Cura and Repetier on my modified Davinci 1.0a) 1 unit = 1 mm. So to convert to inches: 2.54 in/cm *10 mm/cm = 25.4 mm/in I now have: 2.54 * 10 = inches; // 1/4 in sphere: sphere(r=1/4*inches); thanks for helping me clear this up! -- Sent from: http://forum.openscad.org/

AC

A. Craig West

Mon, Aug 24, 2020 2:47 PM

Openscad only has one output format, stl, which is unitless. It is worth
noting that it works in geometric shapes, which are also unitless...

On Mon, 24 Aug 2020, 10:44 jordanthompson, Jordan@thompco.com wrote:

That is what I wound up doing but it surprised me that literally
EVERYWHERE I
read, OpenScad was unit-less.
In fact (at least with Cura and Repetier on my modified Davinci 1.0a) 1
unit
= 1 mm. So to convert to inches:

2.54 in/cm *10 mm/cm = 25.4 mm/in

I now have:
2.54 * 10 = inches;

// 1/4 in sphere:
sphere(r=1/4*inches);

thanks for helping me clear this up!

--
Sent from: http://forum.openscad.org/

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

Openscad only has one output format, stl, which is unitless. It is worth noting that it works in geometric shapes, which are also unitless... On Mon, 24 Aug 2020, 10:44 jordanthompson, <Jordan@thompco.com> wrote: > That is what I wound up doing but it surprised me that literally > EVERYWHERE I > read, OpenScad was unit-less. > In fact (at least with Cura and Repetier on my modified Davinci 1.0a) 1 > unit > = 1 mm. So to convert to inches: > > 2.54 in/cm *10 mm/cm = 25.4 mm/in > > I now have: > 2.54 * 10 = inches; > > // 1/4 in sphere: > sphere(r=1/4*inches); > > thanks for helping me clear this up! > > > > -- > Sent from: http://forum.openscad.org/ > > _______________________________________________ > OpenSCAD mailing list > Discuss@lists.openscad.org > http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org >

J

jordanthompson

Mon, Aug 24, 2020 2:47 PM

I just read this and it is exactly what I wound up doing earlier. Thanks
very much for your help

--
Sent from: http://forum.openscad.org/

I just read this and it is exactly what I wound up doing earlier. Thanks very much for your help -- Sent from: http://forum.openscad.org/

DM

Doug Moen

Mon, Aug 24, 2020 4:19 PM

Openscad only has one output format, stl, which is unitless. It is worth noting that it works in geometric shapes, which are also unitless...

OpenSCAD has many output formats.

For STL export, there is no way to specify units of measurement. Some people say that STL is unitless, but the defacto standard is to interpret the units as millimeters.

For 3MF export, if you don't specify a unit of measurement, it defaults to millimeters. Therefore, OpenSCAD uses millimeters when exporting to 3MF.

For SVG export, OpenSCAD explicitly sets the unit of measurement to be millimeters, even though specifying the unit of measurement is optional.

> Openscad only has one output format, stl, which is unitless. It is worth noting that it works in geometric shapes, which are also unitless... OpenSCAD has many output formats. For STL export, there is no way to specify units of measurement. Some people say that STL is unitless, but the defacto standard is to interpret the units as millimeters. For 3MF export, if you don't specify a unit of measurement, it defaults to millimeters. Therefore, OpenSCAD uses millimeters when exporting to 3MF. For SVG export, OpenSCAD explicitly sets the unit of measurement to be millimeters, even though specifying the unit of measurement is optional.

O

openscad@ray.bellis.me.uk

Thu, Aug 27, 2020 8:54 AM

On 24/08/2020 15:44, jordanthompson wrote:

That is what I wound up doing but it surprised me that literally EVERYWHERE I
read, OpenScad was unit-less.
In fact (at least with Cura and Repetier on my modified Davinci 1.0a) 1 unit
= 1 mm. So to convert to inches:

2.54 in/cm *10 mm/cm = 25.4 mm/in

I now have:
2.54 * 10 = inches;

// 1/4 in sphere:
sphere(r=1/4*inches);

thanks for helping me clear this up!

You could always just build your model as if the units are inches, and
then perform one single "scale" operation at the end when you
instantiate the model:

module my_model() {
// definite geometry here with 1" units
...
}

// scale up for slicer compatibility
scale(inches) my_model();

This removes the need to repeatedly use "* inches" throughout the model.

Ray

On 24/08/2020 15:44, jordanthompson wrote: > That is what I wound up doing but it surprised me that literally EVERYWHERE I > read, OpenScad was unit-less. > In fact (at least with Cura and Repetier on my modified Davinci 1.0a) 1 unit > = 1 mm. So to convert to inches: > > 2.54 in/cm *10 mm/cm = 25.4 mm/in > > I now have: > 2.54 * 10 = inches; > > // 1/4 in sphere: > sphere(r=1/4*inches); > > thanks for helping me clear this up! You could always just build your model as if the units are inches, and then perform one single "scale" operation at the end when you instantiate the model: module my_model() { // definite geometry here with 1" units ... } // scale up for slicer compatibility scale(inches) my_model(); This removes the need to repeatedly use "* inches" throughout the model. Ray