why does this innocent piece of code crash?

R1 = 25;
d = 10;
n = 10;
r = 8;

difference()
{
sphere(R1);
for(i=[0:n-1])
rotate([0, 0, i*360/n ]) translate([R1, 0, 0]) tri();
}
module tri()
{
rotate([0, 90, 0])
intersection_for(i=[0:120:359])
rotate(i) translate([d/3, 0, 0]) cylinder(r=d, h = r, center = true);
}

--
Sent from: http://forum.openscad.org/

No crash for me.
Initially it looked like a hang, but it came back eventually, with VEEERY
slow preview motion updates.
I have preference/Turn off rendering at = 100000000 so I didn't get the
warning.

When debugging I changed the loop to angle based

for(a=[0,36,362,363,364,365])
rotate([0, 0, a ])

As I added more 36*n's, preview performance went down quickly.

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

• click on my MichaelAtOz label, there is a link to email me.

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!

Sent from: http://forum.openscad.org/

It is not a real crash, but the session hangs.

I changed the code of tri(), and used a 2D intersection followed by a
linear_extrude. This gives an instant result.

--
Sent from: http://forum.openscad.org/