(newbie 1st post) Cutout with rounded edges
Hey there,
new to OpenSCAD (and CNC in general).
I have found a couple tutorials of how to make a cube with rounded edges, but that's not what I'm after ;)
I have a wooden plate for an enclosure, and it needs a cutout in the shape of the cross section of a typical pill / capsule, i.e. a long-ish rectangle with a half circle at each end.
The out-side of that plate should have rounded-off edges (i.e. that side will be pointing UP on the CNC table)
How would I do that with OpenSCAD primitives?
A box for the plate, and then subtract a box and 2 cylinders from it, sometihg like that? (ok, that would not have rounded edges)
And how would I, in a clever way automatically calculating this independently from some detail changes, (re-)position the whole thing such that the center of that cutout is at the origin (0,0) of the model?
(I have no clue, but my gut feeling tells, me, homing in on that (center marking) should be easier, after getting the orientation of a clamped-down wood plate right enough, than going from corners with some edge sensing tool, that I don't have yet anyway)
OT side note: any recommendations for free or affordable CAM software for this kind of stuff, and tools helping to calculate feed parameters and such?
I have zero clue about all of this.
To make the outside I would take the hull of four rounded cylinders placed
at the corners. You can find those in my library:
https://github.com/nophead/NopSCADlib#Rounded_cylinder
To make the slot I would subtract the hull of two cylinders, or use my slot
module https://github.com/nophead/NopSCADlib#Polyholes
If I wanted the slot at the origin I would simply model it at 0,0 and place
the corners where they should be relative to that.
On Sun, 13 Oct 2019 at 15:51, wellidontknow@gmx.net wrote:
Hey there,
new to OpenSCAD (and CNC in general).
I have found a couple tutorials of how to make a cube with rounded edges,
but that's not what I'm after ;)
I have a wooden plate for an enclosure, and it needs a cutout in the shape
of the cross section of a typical pill / capsule, i.e. a long-ish rectangle
with a half circle at each end.
The out-side of that plate should have rounded-off edges (i.e. that side
will be pointing UP on the CNC table)
How would I do that with OpenSCAD primitives?
A box for the plate, and then subtract a box and 2 cylinders from it,
sometihg like that? (ok, that would not have rounded edges)
And how would I, in a clever way automatically calculating this
independently from some detail changes, (re-)position the whole thing such
that the center of that cutout is at the origin (0,0) of the model?
(I have no clue, but my gut feeling tells, me, homing in on that (center
marking) should be easier, after getting the orientation of a clamped-down
wood plate right enough, than going from corners with some edge sensing
tool, that I don't have yet anyway)
OT side note: any recommendations for free or affordable CAM software for
this kind of stuff, and tools helping to calculate feed parameters and such?
I have zero clue about all of this.
OpenSCAD mailing list
Discuss@lists.openscad.org
http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
Polyholes should always print the correct size if square holes print the
right size on your printer. If not the printers needs calibrating or the
slicer settings are wrong.
The way it works is the vertex count is reduced enough to ensure the
corners don't cut into the circle even when the plastic cuts the corner, so
the hole diameter is set by the flat sides of the polygon. They are outset
correctly to be on the circle, so if your printer prints straight lines in
the right place the hole should be accurate.
On Sun, 13 Oct 2019 at 16:23, adrianv avm4@cornell.edu wrote:
nophead wrote
To make the slot I would subtract the hull of two cylinders, or use my
slot
module https://github.com/nophead/NopSCADlib#Polyholes
Has this evolved since the original hydroraptor post? I tried it a month
ago on my Prusa Mk3 and the polyholes weren't even close to the right
size.
Of course, at this point I don't remember exactly what was wrong, and I
have
three unmarked test prints with different size holes.
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nophead wrote
To make the slot I would subtract the hull of two cylinders, or use my
slot
module https://github.com/nophead/NopSCADlib#Polyholes
Has this evolved since the original hydroraptor post? I tried it a month
ago on my Prusa Mk3 and the polyholes weren't even close to the right size.
Of course, at this point I don't remember exactly what was wrong, and I have
three unmarked test prints with different size holes.
--
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I scrutinized my code and realized it doesn't match the code on hydraraptor.
It seems the code I actually tested came from here:
https://gilesbathgate.com/2016/02/07/polyholes-revisited/ and it looks like
I got the same result you did when testing this code: all holes too big.
nophead wrote
Polyholes should always print the correct size if square holes print the
right size on your printer. If not the printers needs calibrating or the
slicer settings are wrong.
The way it works is the vertex count is reduced enough to ensure the
corners don't cut into the circle even when the plastic cuts the corner,
so
the hole diameter is set by the flat sides of the polygon. They are outset
correctly to be on the circle, so if your printer prints straight lines in
the right place the hole should be accurate.
On Sun, 13 Oct 2019 at 16:23, adrianv <
avm4@
> wrote:
nophead wrote
To make the slot I would subtract the hull of two cylinders, or use my
slot
module https://github.com/nophead/NopSCADlib#Polyholes
Has this evolved since the original hydroraptor post? I tried it a month
ago on my Prusa Mk3 and the polyholes weren't even close to the right
size.
Of course, at this point I don't remember exactly what was wrong, and I
have
three unmarked test prints with different size holes.
--
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Yes that was an interesting conversation with Giles.
Have you tried the formula here:
https://github.com/nophead/NopSCADlib/blob/master/utils/core/polyholes.scad#L30
?
When printed with single outlines, or with the multiple outlines doing the
outer perimeters first, that always gives the correct size for me.
On Mon, 14 Oct 2019 at 00:01, adrianv avm4@cornell.edu wrote:
I scrutinized my code and realized it doesn't match the code on
hydraraptor.
It seems the code I actually tested came from here:
https://gilesbathgate.com/2016/02/07/polyholes-revisited/ and it looks
like
I got the same result you did when testing this code: all holes too big.
nophead wrote
Polyholes should always print the correct size if square holes print the
right size on your printer. If not the printers needs calibrating or the
slicer settings are wrong.
The way it works is the vertex count is reduced enough to ensure the
corners don't cut into the circle even when the plastic cuts the corner,
so
the hole diameter is set by the flat sides of the polygon. They are
outset
correctly to be on the circle, so if your printer prints straight lines
in
the right place the hole should be accurate.
On Sun, 13 Oct 2019 at 16:23, adrianv <
avm4@
> wrote:
nophead wrote
To make the slot I would subtract the hull of two cylinders, or use my
slot
module https://github.com/nophead/NopSCADlib#Polyholes
Has this evolved since the original hydroraptor post? I tried it a
month
ago on my Prusa Mk3 and the polyholes weren't even close to the right
size.
Of course, at this point I don't remember exactly what was wrong, and I
have
three unmarked test prints with different size holes.
--
Sent from: http://forum.openscad.org/
OpenSCAD mailing list
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