T
tjtr33@gmail.com
Tue, Apr 5, 2022 9:05 AM
Hello, new to OpenSCAD, so asking if my solution is good.
I want a cylindrical cam to drive a shaft up & down, by bearing on a crosspin in the shaft. I divided the cam into pie shaped slices and get the profile i want. BUT it seem kludgy, so how might this be done?
I looked at genertating the interior and exterior cylindric shells, but could not guess how to join them.
I see libraries for threads that are not ‘steppy’, but my attemps require hundreds of faces before any ‘smoothness’ is seen. Its quick to display tho.
In actual manufacture this shape can be milled if the cyclinder is horizontal(alligned X) and the center axis motion is synced with A axis ( around X). The motion would be ‘cosine-uous’ (?)
comments? Thx TomP
Hello, new to OpenSCAD, so asking if my solution is good.
I want a cylindrical cam to drive a shaft up & down, by bearing on a crosspin in the shaft. I divided the cam into pie shaped slices and get the profile i want. BUT it seem kludgy, so how might this be done?
I looked at genertating the interior and exterior cylindric shells, but could not guess how to join them.
I see libraries for threads that are not ‘steppy’, but my attemps require hundreds of faces before any ‘smoothness’ is seen. Its quick to display tho.
In actual manufacture this shape can be milled if the cyclinder is horizontal(alligned X) and the center axis motion is synced with A axis ( around X). The motion would be ‘cosine-uous’ (?)
comments? Thx TomP
L
larry
Tue, Apr 5, 2022 2:05 PM
Hello, new to OpenSCAD, so asking if my solution is good.
I want a cylindrical cam to drive a shaft up & down, by bearing on a
crosspin in the shaft. I divided the cam into pie shaped slices and
get the profile i want. BUT it seem kludgy, so how might this be
done?
Leaving the dimensions and calculations up to you, I'd do it something
like this:
$fn=60;
module cam() {
union() {
cylinder(h=30,r=10);
cylinder(h=10,r=15);
}
}
difference() {
cam();
cylinder(h=60,r=7,center=true);
translate([8,0,37])
rotate([0,40,0])
cube(35,center=true);
}
I looked at genertating the interior and exterior cylindric shells,
but could not guess how to join them.
I see libraries for threads that are not ‘steppy’, but my attemps
require hundreds of faces before any ‘smoothness’ is seen. Its quick
to display tho.
In actual manufacture this shape can be milled if the cyclinder is
horizontal(alligned X) and the center axis motion is synced with A
axis ( around X). The motion would be ‘cosine-uous’ (?)
comments? Thx TomP
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
On Tue, 2022-04-05 at 09:05 +0000, tjtr33@gmail.com wrote:
> Hello, new to OpenSCAD, so asking if my solution is good.
>
> I want a cylindrical cam to drive a shaft up & down, by bearing on a
> crosspin in the shaft. I divided the cam into pie shaped slices and
> get the profile i want. BUT it seem kludgy, so how might this be
> done?
Leaving the dimensions and calculations up to you, I'd do it something
like this:
$fn=60;
module cam() {
union() {
cylinder(h=30,r=10);
cylinder(h=10,r=15);
}
}
difference() {
cam();
cylinder(h=60,r=7,center=true);
translate([8,0,37])
rotate([0,40,0])
cube(35,center=true);
}
> I looked at genertating the interior and exterior cylindric shells,
> but could not guess how to join them.
>
> I see libraries for threads that are not ‘steppy’, but my attemps
> require hundreds of faces before any ‘smoothness’ is seen. Its quick
> to display tho.
>
> In actual manufacture this shape can be milled if the cyclinder is
> horizontal(alligned X) and the center axis motion is synced with A
> axis ( around X). The motion would be ‘cosine-uous’ (?)
>
>
>
> comments? Thx TomP
>
> _______________________________________________
> OpenSCAD mailing list
> To unsubscribe send an email to discuss-leave@lists.openscad.org
LM
Leonard Martin Struttmann
Tue, Apr 5, 2022 2:30 PM
Hmmm... larry, doesn't your solution give the pin a linear up-and-down
motion, rather than the sinusoidal rate of up-and-down of the OP's?
On Tue, Apr 5, 2022 at 9:06 AM larry lar3ry@sasktel.net wrote:
Hello, new to OpenSCAD, so asking if my solution is good.
I want a cylindrical cam to drive a shaft up & down, by bearing on a
crosspin in the shaft. I divided the cam into pie shaped slices and
get the profile i want. BUT it seem kludgy, so how might this be
done?
Leaving the dimensions and calculations up to you, I'd do it something
like this:
$fn=60;
module cam() {
union() {
cylinder(h=30,r=10);
cylinder(h=10,r=15);
}
}
difference() {
cam();
cylinder(h=60,r=7,center=true);
translate([8,0,37])
rotate([0,40,0])
cube(35,center=true);
}
I looked at genertating the interior and exterior cylindric shells,
but could not guess how to join them.
I see libraries for threads that are not ‘steppy’, but my attemps
require hundreds of faces before any ‘smoothness’ is seen. Its quick
to display tho.
In actual manufacture this shape can be milled if the cyclinder is
horizontal(alligned X) and the center axis motion is synced with A
axis ( around X). The motion would be ‘cosine-uous’ (?)
comments? Thx TomP
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
Hmmm... larry, doesn't your solution give the pin a linear up-and-down
motion, rather than the sinusoidal rate of up-and-down of the OP's?
On Tue, Apr 5, 2022 at 9:06 AM larry <lar3ry@sasktel.net> wrote:
> On Tue, 2022-04-05 at 09:05 +0000, tjtr33@gmail.com wrote:
> > Hello, new to OpenSCAD, so asking if my solution is good.
> >
> > I want a cylindrical cam to drive a shaft up & down, by bearing on a
> > crosspin in the shaft. I divided the cam into pie shaped slices and
> > get the profile i want. BUT it seem kludgy, so how might this be
> > done?
>
> Leaving the dimensions and calculations up to you, I'd do it something
> like this:
>
> $fn=60;
>
> module cam() {
> union() {
> cylinder(h=30,r=10);
> cylinder(h=10,r=15);
> }
> }
>
> difference() {
> cam();
> cylinder(h=60,r=7,center=true);
> translate([8,0,37])
> rotate([0,40,0])
> cube(35,center=true);
> }
>
>
> > I looked at genertating the interior and exterior cylindric shells,
> > but could not guess how to join them.
> >
> > I see libraries for threads that are not ‘steppy’, but my attemps
> > require hundreds of faces before any ‘smoothness’ is seen. Its quick
> > to display tho.
> >
> > In actual manufacture this shape can be milled if the cyclinder is
> > horizontal(alligned X) and the center axis motion is synced with A
> > axis ( around X). The motion would be ‘cosine-uous’ (?)
> >
> >
> >
> > comments? Thx TomP
> >
> > _______________________________________________
> > 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
>
T
tjtr33@gmail.com
Tue, Apr 5, 2022 2:54 PM
Larry, thanks, but your form has a sharp edge for the cam to ride on. Mine has a flat surface for the dowel to ride on.
As your form rotates that sharp edge willl wear fast ( it is like my 1st attempt).
BTW, the code posted has a simpler single loop now. ( new code appended here )
Thx TomP
Larry, thanks, but your form has a sharp edge for the cam to ride on. Mine has a flat surface for the dowel to ride on.
As your form rotates that sharp edge willl wear fast ( it is like my 1st attempt).
BTW, the code posted has a simpler single loop now. ( new code appended here )
Thx TomP
T
tjtr33@gmail.com
Tue, Apr 5, 2022 3:54 PM
Leonard, Thanks.
Yes my motion is soft at reversals.
please try the rev 5 attachment posted to Larry.
see humper4.mpg
try with mpv —loop humper4.mpg (or vlc and click loop )
Thanks all,
TomP
Leonard, Thanks.
Yes my motion is soft at reversals.
please try the rev 5 attachment posted to Larry.
see humper4.mpg
try with mpv —loop humper4.mpg (or vlc and click loop )
Thanks all,
TomP
L
larry
Tue, Apr 5, 2022 8:38 PM
On Tue, 2022-04-05 at 09:30 -0500, Leonard Martin Struttmann wrote:
Hmmm... larry, doesn't your solution give the pin a linear up-and-
down motion, rather than the sinusoidal rate of up-and-down of the
OP's?
Probably, but that's why I said that I would leave the dimensions and
calculations to Tom.
I see my solution was unsuitable for other reasons, though.
Hello, new to OpenSCAD, so asking if my solution is good.
I want a cylindrical cam to drive a shaft up & down, by bearing
crosspin in the shaft. I divided the cam into pie shaped slices
get the profile i want. BUT it seem kludgy, so how might this be
done?
Leaving the dimensions and calculations up to you, I'd do it
something
like this:
$fn=60;
module cam() {
union() {
cylinder(h=30,r=10);
cylinder(h=10,r=15);
}
}
difference() {
cam();
cylinder(h=60,r=7,center=true);
translate([8,0,37])
rotate([0,40,0])
cube(35,center=true);
}
I looked at genertating the interior and exterior cylindric
but could not guess how to join them.
I see libraries for threads that are not ‘steppy’, but my attemps
require hundreds of faces before any ‘smoothness’ is seen. Its
to display tho.
In actual manufacture this shape can be milled if the cyclinder
horizontal(alligned X) and the center axis motion is synced with
axis ( around X). The motion would be ‘cosine-uous’ (?)
comments? Thx TomP
OpenSCAD mailing list
To unsubscribe send an email to discuss-leave@lists.openscad.org
On Tue, 2022-04-05 at 09:30 -0500, Leonard Martin Struttmann wrote:
> Hmmm... larry, doesn't your solution give the pin a linear up-and-
> down motion, rather than the sinusoidal rate of up-and-down of the
> OP's?
Probably, but that's why I said that I would leave the dimensions and
calculations to Tom.
I see my solution was unsuitable for other reasons, though.
> On Tue, Apr 5, 2022 at 9:06 AM larry <lar3ry@sasktel.net> wrote:
> > On Tue, 2022-04-05 at 09:05 +0000, tjtr33@gmail.com wrote:
> > > Hello, new to OpenSCAD, so asking if my solution is good.
> > >
> > > I want a cylindrical cam to drive a shaft up & down, by bearing
> > on a
> > > crosspin in the shaft. I divided the cam into pie shaped slices
> > and
> > > get the profile i want. BUT it seem kludgy, so how might this be
> > > done?
> >
> > Leaving the dimensions and calculations up to you, I'd do it
> > something
> > like this:
> >
> > $fn=60;
> >
> > module cam() {
> > union() {
> > cylinder(h=30,r=10);
> > cylinder(h=10,r=15);
> > }
> > }
> >
> > difference() {
> > cam();
> > cylinder(h=60,r=7,center=true);
> > translate([8,0,37])
> > rotate([0,40,0])
> > cube(35,center=true);
> > }
> >
> >
> > > I looked at genertating the interior and exterior cylindric
> > shells,
> > > but could not guess how to join them.
> > >
> > > I see libraries for threads that are not ‘steppy’, but my attemps
> > > require hundreds of faces before any ‘smoothness’ is seen. Its
> > quick
> > > to display tho.
> > >
> > > In actual manufacture this shape can be milled if the cyclinder
> > is
> > > horizontal(alligned X) and the center axis motion is synced with
> > A
> > > axis ( around X). The motion would be ‘cosine-uous’ (?)
> > >
> > >
> > >
> > > comments? Thx TomP
> > >
> > > _______________________________________________
> > > 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
