I found some code on thingiverse that does fillets and chamfers on the
top and/or bottom. Simple in concept, slow to render -
https://www.thingiverse.com/thing:2461392   (I found a slight error in
code, not sure if it has been corrected). But, often don't need the base
rounded, if being screwed to  a wall.

On 11/05/2021 15:22, Jordan Brown wrote:

On Tue, May 11, 2021 at 02:22:40PM +0000, Jordan Brown wrote:

I would then first make a module that produces a side with a
specific size and rounding radius:

module qsphere (r)
{
intersection () {
sphere (r);
cube (r+1);
}
}

module side (x, y, r)
{
hull () {
translate ([x-r, y-r,0]) rotate (  0) qsphere (r);
translate ([  r, y-r,0]) rotate ( 90) qsphere (r);
translate ([  r,  r,0]) rotate (180) qsphere (r);
translate ([x-r,  r,0]) rotate (270) qsphere (r);
}
}

side (50,70,10);

then building up a box would be joining 5 of these....

Roger. 

(I named the Eigth-of-a-sphere qsphere for quartersphere. Sue me).

--
** R.E.Wolff@BitWizard.nl ** https://www.BitWizard.nl/ ** +31-15-2049110 **
**    Delftechpark 11 2628 XJ  Delft, The Netherlands.  KVK: 27239233    **
f equals m times a. When your f is steady, and your m is going down
your a is going up.  -- Chris Hadfield about flying up the space shuttle.

It's pretty darn slow, and the output is ugly (stair steps instead of actual
roundovers).  Have you time tested it against minkowski?

BOSL2 has a support for a variety of rounding, either direct rounded cubes
with options to the cuboid() module, or more sophisticated rounding in
rounding.scad.

I usually make boxes with teardrop rounding on the outside bottom (to assure
printability without supports), a big roundover on the vertical edges, a
small roundover on the top, and a small to medium roundover on the bottom
inside by using a combination of offset_sweep and round_corners in BOSL2.
But I wouldn't call this a basic approach.

https://github.com/revarbat/BOSL2/wiki/rounding.scad

mondo wrote

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

I said it was slow. For simple shapes, cubes/whatever, then there are
quicker ways, but it is faster if you run the scad script in AngelCAD,
pretty darn fast, in fact. You can control the stair stepping - it makes
no difference in 3d printing, use finer steps. Minkowski does not do
fillets - it adds, not subtracts the rounding, as does offset in 2d.
Hull just wraps the shape, it does not follow indents. In the past, I've
used freecad, which has useful filleting, and for stuff like boxes I've
generated shaped extrusions to round of the corners by differencing, and
you do not need to go back and alter dimensions as you would need to do
for simpler shapes, using hull or minkowski. But using the code I
mentioned, you can  easily round of the bottom or top edge of shapes,
such as below, and afaik, there is no inbuilt method for filleting in
openscad.

On 11/05/2021 21:20, adrianv wrote:

If you're going to use AngelCAD then....why not just use AngelCAD?

In principle modeling stair-step style should be OK, but it's hard to view
the models, at least in OpenSCAD, due to the moire patterns---it's hard to
tell what the model actually looks like---and it's just an inelegant
technique.  And you don't even get repaid with decent speed for suffering
the inelegance, so I really don't find it compelling.

You can use multiple applications of minkowski to get inside and outside
rounding if you're willing to wait for it.  In 2d this technique is
practical.  As long as your shape's thinnest part is larger than the inside
rounding radius.

module round2d(r, or, ir)
{
offset(or) offset(-ir-or) offset(delta=ir,chamfer=true) children();
}

A similar scheme with minkowski and differences from a cube larger than your
model can round an arbitrary 3d object.  But it may take hours.

My first model relied on minkowski and takes 20 minutes to preview.  Since
then I've spent a lot of time writing code to round things that actually
runs fast, but doing this in a fully general way isn't feasible.  And
you're right: there's no "fillet" command in OpenSCAD.

mondo wrote

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

On 12/05/2021 00:20, adrianv wrote:

I have used AngelCAD, in fact I prefer the structure/language to
openscad scripting, however, the quick f5 rendering in openscad is
useful, and there is more activity here, on the openscad mailing list,
always someone/s can help when you get stuck. Unfortunately, there are
very few folk, at least that I know of, who have an active interest in
AngelCAD, which imnsho is a great pity. However, it is easy enough for
anyone using openscad to drop in the openscad script into AngelCAD and
quickly get an stl file - in a few seconds instead of many minutes, in
many cases.

I use AngelCAD to process OpenSCAD scripts when processing those scripts
directly in OpenSCAD either takes too long or results in flawed STL files.

I find the F5 function in OpenSCAD to be crucial to my development. 
Being able to highlight a line in the code with a "#", or to change a
color or use "%" is essential.  The lack of that feature in AngelCAD is
a show-stopper for me.  Carsten does not seem to feel that these
functions are as important to him as they are to me.

That said, AngelCAD is a wonderful tool for some specific situations.

Jon

On 5/12/2021 10:30 AM, Ray West wrote: