Empathy List Archives

M

MichaelAtOz

Thu, Jan 12, 2017 4:37 AM

This has been driving me nuts.

I have a model with two tubes joined on one side at an angle.
The STL resulting has holes where the two arcs meet:
http://forum.openscad.org/file/n20041/holes_under.jpg
http://forum.openscad.org/file/n20041/holes_closeup.jpg

The two are the same just translated/rotated into the two positions.

I tried moving them in/out a bit, changing the $fa $fs values including to
ridiculous levels of detail, cleaning-up the join of that flat bit. I went
thru more than 10 iterations...

Finally, I rotated one 0.25 degrees on its z-axis, ie spin the cylinder.

Thus, I presume, moved vertices a fraction, overcoming the, again presumed,
floating point problem.

a. A tip

b. While 0.25d is trivial; is there any other way to join cleanly without
having to compromise the design?

I could have fixed the hole, but IMO it shouldn't get generated.

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View this message in context: http://forum.openscad.org/Fix-holes-in-joined-tubes-tip-tp20041.html
Sent from the OpenSCAD mailing list archive at Nabble.com.

This has been driving me nuts. I have a model with two tubes joined on one side at an angle. The STL resulting has holes where the two arcs meet: <http://forum.openscad.org/file/n20041/holes_under.jpg> <http://forum.openscad.org/file/n20041/holes_closeup.jpg> The two are the same just translated/rotated into the two positions. I tried moving them in/out a bit, changing the $fa $fs values including to ridiculous levels of detail, cleaning-up the join of that flat bit. I went thru more than 10 iterations... Finally, I rotated one 0.25 degrees on its z-axis, ie spin the cylinder. Thus, I presume, moved vertices a fraction, overcoming the, again presumed, floating point problem. a. A tip b. While 0.25d is trivial; is there any other way to join cleanly without having to compromise the design? I could have fixed the hole, but IMO it shouldn't get generated. ----- Admin - PM me if you need anything, or if I've done something stupid... Unless specifically shown otherwise above, my contribution is in the Public Domain; to the extent possible under law, I have waived all copyright and related or neighbouring rights to this work. Obviously inclusion of works of previous authors is not included in the above. The TPP is no simple “trade agreement.” Fight it! http://www.ourfairdeal.org/ time is running out! -- View this message in context: http://forum.openscad.org/Fix-holes-in-joined-tubes-tip-tp20041.html Sent from the OpenSCAD mailing list archive at Nabble.com.

M

MichaelAtOz

Thu, Jan 12, 2017 4:41 AM

What the fixed join looks like (with a fraction move apart too - but that was
after confirming the rotate fixed it).
http://forum.openscad.org/file/n20042/holes_fixed.jpg

Admin - PM me if you need anything, or if I've done something stupid...

Unless specifically shown otherwise above, my contribution is in the Public Domain; to the extent possible under law, I have waived all copyright and related or neighbouring rights to this work. Obviously inclusion of works of previous authors is not included in the above.

The TPP is no simple “trade agreement.” Fight it! http://www.ourfairdeal.org/ time is running out!

View this message in context: http://forum.openscad.org/Fix-holes-in-joined-tubes-tip-tp20041p20042.html
Sent from the OpenSCAD mailing list archive at Nabble.com.

What the fixed join looks like (with a fraction move apart too - but that was after confirming the rotate fixed it). <http://forum.openscad.org/file/n20042/holes_fixed.jpg> ----- Admin - PM me if you need anything, or if I've done something stupid... Unless specifically shown otherwise above, my contribution is in the Public Domain; to the extent possible under law, I have waived all copyright and related or neighbouring rights to this work. Obviously inclusion of works of previous authors is not included in the above. The TPP is no simple “trade agreement.” Fight it! http://www.ourfairdeal.org/ time is running out! -- View this message in context: http://forum.openscad.org/Fix-holes-in-joined-tubes-tip-tp20041p20042.html Sent from the OpenSCAD mailing list archive at Nabble.com.

P

Parkinbot

Thu, Jan 12, 2017 1:13 PM

MichaelAtOz wrote

a. A tip
b. While 0.25d is trivial; is there any other way to join cleanly without
having to compromise the design?

I would clip the tubes appropriately before unioning them.

d=10; // distance
demo(x=d, w=60);
demo(x=d, w=-60);

module demo(R=20, r=18, h=40, x=0, w=0)
difference()
{
rotate([w, 0, 0]) // angle
translate([0, 0, x])
Ri(R, r, h);
// clip
translate([0, (w<0?-2:2)R])
cube(4R, center=true);
}

module Ri(R, r, h) linear_extrude(height = h, convexity = 2)
difference(){circle(R); circle(r);}

--
View this message in context: http://forum.openscad.org/Fix-holes-in-joined-tubes-tip-tp20041p20049.html
Sent from the OpenSCAD mailing list archive at Nabble.com.

MichaelAtOz wrote > a. A tip > b. While 0.25d is trivial; is there any other way to join cleanly without > having to compromise the design? I would clip the tubes appropriately before unioning them. > d=10; // distance > demo(x=d, w=60); > demo(x=d, w=-60); > > module demo(R=20, r=18, h=40, x=0, w=0) > difference() > { > rotate([w, 0, 0]) // angle > translate([0, 0, x]) > Ri(R, r, h); > // clip > translate([0, (w<0?-2:2)*R]) > cube(4*R, center=true); > } > > module Ri(R, r, h) linear_extrude(height = h, convexity = 2) > difference(){circle(R); circle(r);} -- View this message in context: http://forum.openscad.org/Fix-holes-in-joined-tubes-tip-tp20041p20049.html Sent from the OpenSCAD mailing list archive at Nabble.com.

discuss@lists.openscad.org

Fix holes in joined tubes - tip

The TPP is no simple “trade agreement.” Fight it! http://www.ourfairdeal.org/ time is running out!

The TPP is no simple “trade agreement.” Fight it! http://www.ourfairdeal.org/ time is running out!