Hi,
Guest
Why does wall thikness differ?
YV
yur_vol@yahoo.com
Sat, Nov 29, 2025 8:55 PM
I was recommended to build flare top separatly via rotate_extrude arc
I did it but noticed that wall thikness is less then stroke_offset made tube.
Why?
Is my way to build offset diameter curve noncorrect?
Another questions:
Are there more elegant way to build tube then hulling?
(BTW I tried chain_hull, no way)
How to calculate tangent angle for bulding top flare curve?
I was recommended to build flare top separatly via rotate_extrude arc\
I did it but noticed that wall thikness is less then stroke_offset made tube.\
Why?\
Is my way to build offset diameter curve noncorrect?
Another questions:\
Are there more elegant way to build tube then hulling?\
(BTW I tried chain_hull, no way)\
\
How to calculate tangent angle for bulding top flare curve?\
PK
Peter Kriens
Tue, Dec 2, 2025 3:06 PM
If you use BOSL2 there is tube() and rect_tube(). Especially tube is very easy to round or chamfer on inside, outside, top, and bottom. I often use them to construct quite complicated circular profiles.
To make the flare, it depends a bit on how you want the flare. Th prism_connector is excellent to make small flares that can act to get a nicely rounded connection to other surfaces:

diff()
tube( od=50, wall=2, h=40)
let(a=parent())
up(10) cuboid([100,100,0]) // reference
let(b=parent())
prism_connector(
circle(d=50),
a, TOP,
b, BOT,
fillet1=5, fillet2=0, overlap=0)
tag("remove")
prism_connector(
circle(d=50-2*2),
a, TOP,
b, TOP,
fillet1=5, fillet2=0, overlap=1)
;
The beauty of the attach mechanism is that you can even connect to non-flat surfaces and get full rounding:

diff()
tube( od=50, wall=2, h=40, anchor=DOWN)
let(a=parent(), ai = parent_part("inside"))
xmove(100) up(20) tube( od=50, wall=2, h=80)
let(b=parent(), bi = parent_part("inside"))
prism_connector( circle(d=20), a, CTR, b, CTR, fillet=3, overlap=0)
tag("remove")
prism_connector( circle(d=20-2*2), ai, CTR, bi, CTR, fillet=3, overlap=1)
;
In this area I find rounded_prism and attach_prism also very easy to use to get well rounded components.
On 29 Nov 2025, at 21:55, yur_vol--- via Discuss discuss@lists.openscad.org wrote:
I was recommended to build flare top separatly via rotate_extrude arc
I did it but noticed that wall thikness is less then stroke_offset made tube.
Why?
Is my way to build offset diameter curve noncorrect?
Another questions:
Are there more elegant way to build tube then hulling?
(BTW I tried chain_hull, no way)
How to calculate tangent angle for bulding top flare curve?
<embed0.png>
<bb_test.scad>_______________________________________________
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
If you use BOSL2 there is tube() and rect_tube(). Especially tube is very easy to round or chamfer on inside, outside, top, and bottom. I often use them to construct quite complicated circular profiles.
To make the flare, it depends a bit on how you want the flare. Th prism_connector is excellent to make small flares that can act to get a nicely rounded connection to other surfaces:

diff()
tube( od=50, wall=2, h=40)
let(a=parent())
up(10) cuboid([100,100,0]) // reference
let(b=parent())
prism_connector(
circle(d=50),
a, TOP,
b, BOT,
fillet1=5, fillet2=0, overlap=0)
tag("remove")
prism_connector(
circle(d=50-2*2),
a, TOP,
b, TOP,
fillet1=5, fillet2=0, overlap=1)
;
The beauty of the attach mechanism is that you can even connect to non-flat surfaces and get full rounding:

diff()
tube( od=50, wall=2, h=40, anchor=DOWN)
let(a=parent(), ai = parent_part("inside"))
xmove(100) up(20) tube( od=50, wall=2, h=80)
let(b=parent(), bi = parent_part("inside"))
prism_connector( circle(d=20), a, CTR, b, CTR, fillet=3, overlap=0)
tag("remove")
prism_connector( circle(d=20-2*2), ai, CTR, bi, CTR, fillet=3, overlap=1)
;
In this area I find rounded_prism and attach_prism also very easy to use to get well rounded components.
> On 29 Nov 2025, at 21:55, yur_vol--- via Discuss <discuss@lists.openscad.org> wrote:
>
> I was recommended to build flare top separatly via rotate_extrude arc
> I did it but noticed that wall thikness is less then stroke_offset made tube.
> Why?
> Is my way to build offset diameter curve noncorrect?
>
> Another questions:
> Are there more elegant way to build tube then hulling?
> (BTW I tried chain_hull, no way)
>
> How to calculate tangent angle for bulding top flare curve?
> <embed0.png>
>
> <bb_test.scad>_______________________________________________
> OpenSCAD mailing list
> To unsubscribe send an email to discuss-leave@lists.openscad.org
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