Greetings all; The current discussion about wrapping text around a cylinder has got me interested in the possability of doing this for some parts of a harmonic drive for cnc stuff that I have designed and made. Couple pix attached, and I want to reverse the extrusion, digging into the wider curves, centered 2 or two chars at a time, not more than .5mm deep into the curved surface between the cylindrical keys which lock these pieces into the surrounding parts. Obviously I can't dig very deep, .5mm max, else it will start a stress fracture. text in pieces like 80, for one of them, 82, for the other, and 40, /, 1; for both of these parts. All placed in the centers of the corresponding outside arc faces. These are pix of two of the 4 parts that change to change the effective gear ratio, in the present case 40/1. All the examples I've looked at the links to them are extruded, and there is no room for an extrusion in these drives. I need indentation to do this. Is this doable? If so, rough idea how? Cheers, Gene Heskett. -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author, 1940) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis

try this code: $fn=90; d=0.5; //depth of engraving cir=[for(i=[0:360/20:360])[19*cos(i),19*sin(i),10]]; function ang(x,y)= x>=0&&y>=0?atan(y/x):x<0&&y>=0?180-abs(atan(y/x)):x<0&&y<0?180+abs(atan(y/x)):360-abs(atan(y/x)); ang=[for(p=cir)ang(p.x,p.y)]; text="text to be engraved"; difference(){ cylinder(r=20,h=20); difference(){ for(i=[0:len(cir)-1]) translate(cir[i])rotate([0,0,ang[i]])rotate([90,0,90])linear_extrude(1)text(text[i],5); cylinder(r=20-d,h=20);}} basic idea: align the text in circle cut the text with a cylinder form a bigger cylinder (bigger by the depth of engraving ) and cut in the above text On Tue, 5 Apr 2022 at 05:46, gene heskett <gheskett@shentel.net> wrote: > Greetings all; > > The current discussion about wrapping text around a cylinder has got me > interested in the possability of doing this for some parts of a harmonic > drive for cnc stuff that I have designed and made. > > Couple pix attached, and I want to reverse the extrusion, digging into > the wider curves, centered 2 or two chars at a time, not more than .5mm > deep into the curved surface between the cylindrical keys which lock > these pieces into the surrounding parts. Obviously I can't dig very deep, > .5mm max, else it will start a stress fracture. > > text in pieces like 80, for one of them, 82, for the other, and 40, /, 1; > for both of these parts. All placed in the centers of the corresponding > outside arc faces. These are pix of two of the 4 parts that change to > change the effective gear ratio, in the present case 40/1. > > All the examples I've looked at the links to them are extruded, and there > is no room for an extrusion in these drives. I need indentation to do > this. > > Is this doable? > > If so, rough idea how? > > Cheers, Gene Heskett. > -- > "There are four boxes to be used in defense of liberty: > soap, ballot, jury, and ammo. Please use in that order." > -Ed Howdershelt (Author, 1940) > If we desire respect for the law, we must first make the law respectable. > - Louis D. Brandeis > _______________________________________________ > OpenSCAD mailing list > To unsubscribe send an email to discuss-leave@lists.openscad.org >

On Monday, 4 April 2022 21:32:42 EDT Sanjeev Prabhakar wrote: > try this code: > > $fn=90; > d=0.5; //depth of engraving > cir=[for(i=[0:360/20:360])[19*cos(i),19*sin(i),10]]; > function ang(x,y)= > x>=0&&y>=0?atan(y/x):x<0&&y>=0?180-abs(atan(y/x)):x<0&&y<0?180+abs(atan > (y/x)):360-abs(atan(y/x)); ang=[for(p=cir)ang(p.x,p.y)]; > text="text to be engraved"; > > difference(){ > cylinder(r=20,h=20); > difference(){ > for(i=[0:len(cir)-1]) > translate(cir[i])rotate([0,0,ang[i]])rotate([90,0,90])linear_extrude(1) > text(text[i],5); cylinder(r=20-d,h=20);}} > > basic idea: > align the text in circle > cut the text with a cylinder > form a bigger cylinder (bigger by the depth of engraving ) and cut in > the above text That sounds as if it might be made to work, by forming a thin ring whose OD is the current OD and .4mm thick, put the text in it as cutouts and place that around the existing piece after reducing its OD by .4 mm. That I think I can do when I next have both eyes open. Thank you. > On Tue, 5 Apr 2022 at 05:46, gene heskett <gheskett@shentel.net> wrote: > > Greetings all; > > > > The current discussion about wrapping text around a cylinder has got > > me interested in the possability of doing this for some parts of a > > harmonic drive for cnc stuff that I have designed and made. > > > > Couple pix attached, and I want to reverse the extrusion, digging > > into > > the wider curves, centered 2 or two chars at a time, not more than > > .5mm deep into the curved surface between the cylindrical keys which > > lock these pieces into the surrounding parts. Obviously I can't dig > > very deep, .5mm max, else it will start a stress fracture. > > > > text in pieces like 80, for one of them, 82, for the other, and 40, > > /, 1; for both of these parts. All placed in the centers of the > > corresponding outside arc faces. These are pix of two of the 4 parts > > that change to change the effective gear ratio, in the present case > > 40/1. > > > > All the examples I've looked at the links to them are extruded, and > > there is no room for an extrusion in these drives. I need > > indentation to do this. > > > > Is this doable? > > > > If so, rough idea how? > > > > Cheers, Gene Heskett. > > -- > > > > "There are four boxes to be used in defense of liberty: > > soap, ballot, jury, and ammo. Please use in that order." > > > > -Ed Howdershelt (Author, 1940) > > If we desire respect for the law, we must first make the law > > respectable.> > > - Louis D. Brandeis > > > > _______________________________________________ > > OpenSCAD mailing list > > To unsubscribe send an email to discuss-leave@lists.openscad.org Cheers, Gene Heskett. -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author, 1940) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis