Helix with circular cross-section
fwiw, I made a short length of threaded rod, about a month or two ago,
with left and right hand threads, and matching huts, one lh thread,
t'other rh. (also an attempt at a nut that 'would go both ways). I
showed it to someone I know, but he liked it so much, he put it in his
pocket. This one will be toroidal, too big for a pocket. With sufficient
stiction between the nuts and the rod, if you hold one nut you think you
can tighten the other one against it, but you can't.
On 26/10/2024 18:56, John David via Discuss wrote:
Maybe like the screws that can be tightened turning both left and right?
https://www.youtube.com/watch?app=desktop&v=_48-Ike_i6M
https://www.youtube.com/watch?app=desktop&v=_48-Ike_i6M
That can hurt your noggin, but I get it...
EBo --
Why wouldn't you be able to tighten one nut against another on the helical
threaded rod? It does seem like the nuts would need to have their
threading skewed by the helical curve and angle.
For anyone who wants a simple example of the double threaded screw, there's
one here:
https://github.com/BelfrySCAD/BOSL2/wiki/threading.scad#module-threaded_rod
See Example 7.
On Sun, Oct 27, 2024 at 6:51 AM Raymond West via Discuss <
discuss@lists.openscad.org> wrote:
fwiw, I made a short length of threaded rod, about a month or two ago,
with left and right hand threads, and matching huts, one lh thread,
t'other rh. (also an attempt at a nut that 'would go both ways). I
showed it to someone I know, but he liked it so much, he put it in his
pocket. This one will be toroidal, too big for a pocket. With sufficient
stiction between the nuts and the rod, if you hold one nut you think you
can tighten the other one against it, but you can't.
On 26/10/2024 18:56, John David via Discuss wrote:
Maybe like the screws that can be tightened turning both left and right?
https://www.youtube.com/watch?app=desktop&v=_48-Ike_i6M
https://www.youtube.com/watch?app=desktop&v=_48-Ike_i6M
That can hurt your noggin, but I get it...
EBo --
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
Hi Adrian,
if you hold one nut, the stiction can hold the stud, allowing the second
nut to be tightened against the first, but when the second nut touches
the first nut, the stud starts turning in the same direction as the
second nut, thus it can not tighten against the first nut. I've not got
my original, since a friend 'borrowed' it, so that is the best
explanation that I can remember. If you hold the stud, then you can
tighten both nuts together, but swap them over, and turn each in the
same direction, they move apart, of course.
I'm not sure of any practical application, but there are plenty of
double threaded nuts and bolts, but with the threads going in the same
direction. Many occurred when going from imperial to metric threads in
the UK🙁.
Best wishes,
Ray
On 28/10/2024 21:28, Adrian Mariano via Discuss wrote:
Why wouldn't you be able to tighten one nut against another on the
helical threaded rod? It does seem like the nuts would need to have
their threading skewed by the helical curve and angle.
For anyone who wants a simple example of the double threaded screw,
there's one here:
https://github.com/BelfrySCAD/BOSL2/wiki/threading.scad#module-threaded_rod
See Example 7.
On Sun, Oct 27, 2024 at 6:51 AM Raymond West via Discuss
discuss@lists.openscad.org wrote:
fwiw, I made a short length of threaded rod, about a month or two
ago,
with left and right hand threads, and matching huts, one lh thread,
t'other rh. (also an attempt at a nut that 'would go both ways). I
showed it to someone I know, but he liked it so much, he put it in
his
pocket. This one will be toroidal, too big for a pocket. With
sufficient
stiction between the nuts and the rod, if you hold one nut you
think you
can tighten the other one against it, but you can't.
On 26/10/2024 18:56, John David via Discuss wrote:
Maybe like the screws that can be tightened turning both left
and right?
<https://www.youtube.com/watch?app=desktop&v=_48-Ike_i6M>
<https://www.youtube.com/watch?app=desktop&v=_48-Ike_i6M
<https://www.youtube.com/watch?app=desktop&v=_48-Ike_i6M>>
That can hurt your noggin, but I get it...
EBo --
_______________________________________________
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
OpenSCAD mailing list
To unsubscribe send an email todiscuss-leave@lists.openscad.org
Ray, I think you're talking about the double threaded rod and I
misinterpreted you and thought you were referring to the threaded helix
that you posted. I have printed the double threaded rod (from the above
posted BOSL2 example) and am still in possession of the print, so I know
how that thing behaves.
On Tue, Oct 29, 2024 at 4:14 PM Raymond West via Discuss <
discuss@lists.openscad.org> wrote:
Hi Adrian,
if you hold one nut, the stiction can hold the stud, allowing the second
nut to be tightened against the first, but when the second nut touches the
first nut, the stud starts turning in the same direction as the second nut,
thus it can not tighten against the first nut. I've not got my original,
since a friend 'borrowed' it, so that is the best explanation that I can
remember. If you hold the stud, then you can tighten both nuts together,
but swap them over, and turn each in the same direction, they move apart,
of course.
I'm not sure of any practical application, but there are plenty of double
threaded nuts and bolts, but with the threads going in the same direction.
Many occurred when going from imperial to metric threads in the UK🙁.
Best wishes,
Ray
On 28/10/2024 21:28, Adrian Mariano via Discuss wrote:
Why wouldn't you be able to tighten one nut against another on the helical
threaded rod? It does seem like the nuts would need to have their
threading skewed by the helical curve and angle.
For anyone who wants a simple example of the double threaded screw,
there's one here:
https://github.com/BelfrySCAD/BOSL2/wiki/threading.scad#module-threaded_rod
See Example 7.
On Sun, Oct 27, 2024 at 6:51 AM Raymond West via Discuss <
discuss@lists.openscad.org> wrote:
fwiw, I made a short length of threaded rod, about a month or two ago,
with left and right hand threads, and matching huts, one lh thread,
t'other rh. (also an attempt at a nut that 'would go both ways). I
showed it to someone I know, but he liked it so much, he put it in his
pocket. This one will be toroidal, too big for a pocket. With sufficient
stiction between the nuts and the rod, if you hold one nut you think you
can tighten the other one against it, but you can't.
On 26/10/2024 18:56, John David via Discuss wrote:
Maybe like the screws that can be tightened turning both left and right?
https://www.youtube.com/watch?app=desktop&v=_48-Ike_i6M
https://www.youtube.com/watch?app=desktop&v=_48-Ike_i6M
That can hurt your noggin, but I get it...
EBo --
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
Hi!
Can someone tell me the z-position of a threaded_rod in BOSL2 when it’s not translated?
I’m using it in a difference function to cut a thread out of a tube.
difference() {
cylinder(h=50, d=16, $fn=150);
translate([0,0,1.5])
cylinder(h=32.5, d=12);
translate([0,0,34])
threaded_rod(d=12, l=16, pitch=2, internal=false, bevel=0.5);
}
That should bring the top of the rod to the top of the tube, but it doesn’t. Instead the tube is closed at the top.
I also tried adding half the rod’s length to the translation, in case it’s originally centered. That produces an open tube, but with a rim at the top.
I should mention that I’m blind and can’t use the preview.
Any advice is welcome.
Cheers! Robbie
On 6/25/25 13:04, Robbie Sandberg via Discuss wrote:
Hi!
Can someone tell me the z-position of a threaded_rod in BOSL2 when it’s not translated?
I’m using it in a difference function to cut a thread out of a tube.
difference() {
cylinder(h=50, d=16, $fn=150);
translate([0,0,1.5])
cylinder(h=32.5, d=12);
translate([0,0,34])
threaded_rod(d=12, l=16, pitch=2, internal=false, bevel=0.5);
}
That should bring the top of the rod to the top of the tube, but it doesn’t. Instead the tube is closed at the top.
I also tried adding half the rod’s length to the translation, in case it’s originally centered. That produces an open tube, but with a rim at the top.
I should mention that I’m blind and can’t use the preview.
Any advice is welcome.
That is a limitation I don't have, but what I do in such a case is make
the threaded rod I'm using for a difference, enough longer that both
ends project beyond the length of the item its being differenced out of.
Unfortunately I don't see the code for "threaded_rod()" so I can't test
it Can that be posted?l
Cheers! Robbie
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
Cheers, Gene Heskett, CET.
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
As the subject says, it's a BOSL2 question, which is where threaded_rod is
to be found.
The cylinder() module by default places the cylinder with its bottom on the
XY plane. You can use center=true to make it center. The BOSL2 commands by
default center objects, so the threaded rod will be centered. It may work
better to combine this with cyl() which automatically centers for
consistent behavior. Note that you probably want internal=true if you're
making a threaded hole. Your model has a 50 unit tall cylinder, so its
top is at z=50. The top of the threaded rod, which has height 16, is at
z=8. Since you are beveling you will not want to follow Gene's advice to
make it oversized. You have a but your threaded rod is only 16 units
tall. So you need to raise it by 50-8 units. So like this:
difference() {
cylinder(h=50, d=16, $fn=150);
translate([0,0,1.5])
cylinder(h=32.5, d=12);
up(50-8)
threaded_rod(d=12, l=16, pitch=2, internal=true, bevel2=0.5, bevel1=0);
}
I took the bevel off the bottom because that works better. Note that
internal=true causes the bevels to reverse. And you may want to go up by
slightly more to ensure no issues with coplanar faces, but in this case I
think it only matters in preview, which doesn't affect you. By slightly
more I mean 0.01 units.
The easier way to address this is with attachments. That looks like this:
include<BOSL2/std.scad>
include<BOSL2/threading.scad>
diff()
cyl(h=50,d=16, $fn=150){
up(1.5)attach(BOT,BOT,inside=true) cyl(h=32.5,d=12);
attach(TOP,TOP,inside=true)
threaded_rod(d=12, l=16, pitch=2, internal=true, bevel2=0.5,
bevel1=0);
}
You can also in general explicitly anchor BOSL2 objects so you know where
they are, e.g. with anchor=BOTTOM to put the bottom at the origin, or
anchor=CENTER to center it at the origin.
On Wed, Jun 25, 2025 at 2:15 PM gene heskett via Discuss <
discuss@lists.openscad.org> wrote:
On 6/25/25 13:04, Robbie Sandberg via Discuss wrote:
Hi!
Can someone tell me the z-position of a threaded_rod in BOSL2 when it’s
not translated?
I’m using it in a difference function to cut a thread out of a tube.
difference() {
cylinder(h=50, d=16, $fn=150);
translate([0,0,1.5])
cylinder(h=32.5, d=12);
translate([0,0,34])
threaded_rod(d=12, l=16, pitch=2, internal=false, bevel=0.5);
}
That should bring the top of the rod to the top of the tube, but it
doesn’t. Instead the tube is closed at the top.
I also tried adding half the rod’s length to the translation, in case
it’s originally centered. That produces an open tube, but with a rim at the
top.
I should mention that I’m blind and can’t use the preview.
Any advice is welcome.
That is a limitation I don't have, but what I do in such a case is make
the threaded rod I'm using for a difference, enough longer that both
ends project beyond the length of the item its being differenced out of.
Unfortunately I don't see the code for "threaded_rod()" so I can't test
it Can that be posted?l
Cheers! Robbie
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
Cheers, Gene Heskett, CET.
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
On 6/25/25 16:39, Adrian Mariano via Discuss wrote:
As the subject says, it's a BOSL2 question, which is where threaded_rod is
to be found.
Unfortunately I can't make it work by adding
include </home/gene/.local/share/OpenSCAD/libraries/BOSL2/std.scad>
include
</home/gene/.local/share/OpenSCAD/libraries/BOSL2/threading.scad; as
lines 3 & 4..
Perhaps someone else can help this gentleman. Obviously Adrian, I need
to get more familiar with BOSL2, and/or I need to dl a newer version.
It is now complaining about an error in shapes3d.scad line 15. But it
won't copy/paste from the error box. URL for latest?
The cylinder() module by default places the cylinder with its bottom on the
XY plane. You can use center=true to make it center. The BOSL2 commands by
default center objects, so the threaded rod will be centered. It may work
better to combine this with cyl() which automatically centers for
consistent behavior. Note that you probably want internal=true if you're
making a threaded hole. Your model has a 50 unit tall cylinder, so its
top is at z=50. The top of the threaded rod, which has height 16, is at
z=8. Since you are beveling you will not want to follow Gene's advice to
make it oversized. You have a but your threaded rod is only 16 units
tall. So you need to raise it by 50-8 units. So like this:
difference() {
cylinder(h=50, d=16, $fn=150);
translate([0,0,1.5])
cylinder(h=32.5, d=12);
up(50-8)
threaded_rod(d=12, l=16, pitch=2, internal=true, bevel2=0.5, bevel1=0);
}
I took the bevel off the bottom because that works better. Note that
internal=true causes the bevels to reverse. And you may want to go up by
slightly more to ensure no issues with coplanar faces, but in this case I
think it only matters in preview, which doesn't affect you. By slightly
more I mean 0.01 units.
The easier way to address this is with attachments. That looks like this:
include<BOSL2/std.scad>
include<BOSL2/threading.scad>
diff()
cyl(h=50,d=16, $fn=150){
up(1.5)attach(BOT,BOT,inside=true) cyl(h=32.5,d=12);
attach(TOP,TOP,inside=true)
threaded_rod(d=12, l=16, pitch=2, internal=true, bevel2=0.5,
bevel1=0);
}
You can also in general explicitly anchor BOSL2 objects so you know where
they are, e.g. with anchor=BOTTOM to put the bottom at the origin, or
anchor=CENTER to center it at the origin.
On Wed, Jun 25, 2025 at 2:15 PM gene heskett via Discuss <
discuss@lists.openscad.org> wrote:
On 6/25/25 13:04, Robbie Sandberg via Discuss wrote:
Hi!
Can someone tell me the z-position of a threaded_rod in BOSL2 when it’s
not translated?
I’m using it in a difference function to cut a thread out of a tube.
difference() {
cylinder(h=50, d=16, $fn=150);
translate([0,0,1.5])
cylinder(h=32.5, d=12);
translate([0,0,34])
threaded_rod(d=12, l=16, pitch=2, internal=false, bevel=0.5);
}
That should bring the top of the rod to the top of the tube, but it
doesn’t. Instead the tube is closed at the top.
I also tried adding half the rod’s length to the translation, in case
it’s originally centered. That produces an open tube, but with a rim at the
top.
I should mention that I’m blind and can’t use the preview.
Any advice is welcome.
That is a limitation I don't have, but what I do in such a case is make
the threaded rod I'm using for a difference, enough longer that both
ends project beyond the length of the item its being differenced out of.
Unfortunately I don't see the code for "threaded_rod()" so I can't test
it Can that be posted?l
Cheers! Robbie
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
Cheers, Gene Heskett, CET.
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
Cheers, Gene Heskett, CET.
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
The example I posted does not require a recent copy of BOSL2, so your
issues may depend on installation issues, but you didn't post the error
messages so that makes a more detailed diagnosis impossible. You should be
able to include BOSL2 without needing the full path if you have your
library path set up correctly.
If you want the most recent BOSL2 it can be found at:
https://github.com/BelfrySCAD/BOSL2
On Wed, Jun 25, 2025 at 8:40 PM gene heskett via Discuss <
discuss@lists.openscad.org> wrote:
On 6/25/25 16:39, Adrian Mariano via Discuss wrote:
As the subject says, it's a BOSL2 question, which is where threaded_rod
is
to be found.
Unfortunately I can't make it work by adding
include </home/gene/.local/share/OpenSCAD/libraries/BOSL2/std.scad>
include
</home/gene/.local/share/OpenSCAD/libraries/BOSL2/threading.scad; as
lines 3 & 4..
Perhaps someone else can help this gentleman. Obviously Adrian, I need
to get more familiar with BOSL2, and/or I need to dl a newer version.
It is now complaining about an error in shapes3d.scad line 15. But it
won't copy/paste from the error box. URL for latest?
The cylinder() module by default places the cylinder with its bottom on
the
XY plane. You can use center=true to make it center. The BOSL2 commands
by
default center objects, so the threaded rod will be centered. It may
work
better to combine this with cyl() which automatically centers for
consistent behavior. Note that you probably want internal=true if
you're
making a threaded hole. Your model has a 50 unit tall cylinder, so its
top is at z=50. The top of the threaded rod, which has height 16, is at
z=8. Since you are beveling you will not want to follow Gene's advice to
make it oversized. You have a but your threaded rod is only 16 units
tall. So you need to raise it by 50-8 units. So like this:
difference() {
cylinder(h=50, d=16, $fn=150);
translate([0,0,1.5])
cylinder(h=32.5, d=12);
up(50-8)
threaded_rod(d=12, l=16, pitch=2, internal=true, bevel2=0.5,
bevel1=0);
}
I took the bevel off the bottom because that works better. Note that
internal=true causes the bevels to reverse. And you may want to go up by
slightly more to ensure no issues with coplanar faces, but in this case I
think it only matters in preview, which doesn't affect you. By slightly
more I mean 0.01 units.
The easier way to address this is with attachments. That looks like
this:
include<BOSL2/std.scad>
include<BOSL2/threading.scad>
diff()
cyl(h=50,d=16, $fn=150){
up(1.5)attach(BOT,BOT,inside=true) cyl(h=32.5,d=12);
attach(TOP,TOP,inside=true)
threaded_rod(d=12, l=16, pitch=2, internal=true, bevel2=0.5,
bevel1=0);
}
You can also in general explicitly anchor BOSL2 objects so you know where
they are, e.g. with anchor=BOTTOM to put the bottom at the origin, or
anchor=CENTER to center it at the origin.
On Wed, Jun 25, 2025 at 2:15 PM gene heskett via Discuss <
discuss@lists.openscad.org> wrote:
On 6/25/25 13:04, Robbie Sandberg via Discuss wrote:
Hi!
Can someone tell me the z-position of a threaded_rod in BOSL2 when it’s
not translated?
I’m using it in a difference function to cut a thread out of a tube.
difference() {
cylinder(h=50, d=16, $fn=150);
translate([0,0,1.5])
cylinder(h=32.5, d=12);
translate([0,0,34])
threaded_rod(d=12, l=16, pitch=2, internal=false, bevel=0.5);
}
That should bring the top of the rod to the top of the tube, but it
doesn’t. Instead the tube is closed at the top.
I also tried adding half the rod’s length to the translation, in case
it’s originally centered. That produces an open tube, but with a rim at
the
top.
I should mention that I’m blind and can’t use the preview.
Any advice is welcome.
That is a limitation I don't have, but what I do in such a case is make
the threaded rod I'm using for a difference, enough longer that both
ends project beyond the length of the item its being differenced out of.
Unfortunately I don't see the code for "threaded_rod()" so I can't test
it Can that be posted?l
Cheers! Robbie
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
Cheers, Gene Heskett, CET.
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law
respectable.
- Louis D. Brandeis
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
Cheers, Gene Heskett, CET.
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
On 6/25/25 21:07, Adrian Mariano via Discuss wrote:
The example I posted does not require a recent copy of BOSL2, so your
issues may depend on installation issues, but you didn't post the error
messages so that makes a more detailed diagnosis impossible. You should be
able to include BOSL2 without needing the full path if you have your
library path set up correctly.
Apparently I don't. And its not well covered in the cheat sheet.
Thank you.
Cheers, Gene Heskett, CET.
--
"There are four boxes to be used in defense of liberty:
soap, ballot, jury, and ammo. Please use in that order."
-Ed Howdershelt (Author, 1940)
If we desire respect for the law, we must first make the law respectable.
- Louis D. Brandeis