how write this model (Gravitational potential well) with openscad: https://www.thingiverse.com/thing:561757 here an pdf instruction: https://cdn.thingiverse.com/assets/53/47/ae/bf/59/orbits_description.pdf I'd like do it for the my son's classroom! Thankyou in advance for your help! Oda -- Sent from: http://forum.openscad.org/

The dirty part of the work is the groove ... > $fn=60; > > difference() > { > well(); > translate([0, 25, -79.7]) > groove(); > } > module groove(l=105, w=11) > { > translate([l, 0, 0]) > rotate([-90+w, 0, 0]) > cylinder(r=10, h=l); > } > > module well(r=120) > { > intersection() > { > rotate_extrude() polygon(100*grav()); > cube([2*r, 2*r, 2000], center = true); > } > > function grav(r=1.75, r0=.4, steps = 30) = concat([for > (i=[r0:(r-r0)/steps:r]) [i, -1/i]], [[r, -1/r0] ]); > } -- Sent from: http://forum.openscad.org/

Wonderfull! Thankyou! Oda -- Sent from: http://forum.openscad.org/