Square Tray 75x75x15 with Rounded Rim

// Small square tray 75x75x15. Wall top = rounded 2.4R, built from stacked rings. $fn=64; N=24; e=0.01; L=75; W=75; R=12; bt=5; wt=5; H=15; rt=2.4; ff=1; ch=0.6; ri=R-wt; zt=H-rt; module rr(l,w,r) offset(r=r) square([l-2*r,w-2*r],center=true); module sl(z,l,w,r) translate([0,0,z]) linear_extrude(e) rr(l,w,r); // lower body: chamfered base, walls up to zt, 1 mm floor fillet difference(){ hull(){ sl(0,L-2*ch,W-2*ch,R-ch); sl(ch,L,W,R); sl(zt,L,W,R); } hull(){ for(k=[0:10]){a=9*k; i=ff*(1-sin(a)); sl(bt+ff*(1-cos(a)),L-2*wt-2*i,W-2*wt-2*i,ri-i);} sl(zt+1,L-2*wt,W-2*wt,ri); } } // rounded wall top: thin rings narrowing toward the top for(k=[0:N-1]){ t=rt*(k+0.5)/N; d=rt-sqrt(rt*rt-t*t); translate([0,0,zt+rt*k/N-e]) linear_extrude(rt/N+e) difference(){ rr(L-2*d,W-2*d,R-d); rr(L-2*wt+2*d,W-2*wt+2*d,ri+d); } }

Parameters

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