////////////////////////////////////////////////////////////////////// // LibFile: hinges.scad // Functions and modules for creating hinges and snap-locking hinged parts. // Includes: // include // include // FileGroup: Parts // FileSummary: Hinges and snap-locking hinged parts. ////////////////////////////////////////////////////////////////////// include include // Section: Hinges // Module: knuckle_hinge() // Usage: // knuckle_hinge(length, offset, segs, [inner], [arm_height=], [arm_angle=], [fill=], [clear_top=], [gap=], [round_top=], [round_bot=], [knuckle_diam=], [pin_diam=], [pin_fn=], [anchor=], [spin=], [orient=]) [ATTACHMENTS]; // Description: // Construct standard knuckle hinge in two parts using a hinge pin that must be separately supplied. The default is configured to use a piece of 1.75 mm filament as the hinge pin, // but you can select any dimensions you like to use a screw or other available pin material. The BOTTOM of the hinge is its mount point, which is aligned with // the hinge pin centersurface, and the hinge pin hole is the CENTER of the hinge. // The offset is the distance from a vertical mounting point to the center of the hinge pin. The hinge barrel is held by an angled support and // vertical support. The length of the angled support is determined by its angle and the offset. You specify the length of the vertical support with the // arm_height parameter. // Figure(2D,NoScales): The basic hinge form appears on the left. If fill is set to true the gap between the mount surface and hinge arm is filled as shown on the right. // _hinge_profile(4, 5, $fn=32, fill=false); // right(13)_hinge_profile(4, 5, $fn=32, fill=true); // fwd(9)stroke([[0,0],[4,4],[4,9]], width=.3,color="black"); // stroke([[5,-5],[5,0]], endcaps="arrow2", color="blue",width=.15); // color("blue"){move([6.2,-2.5])text("arm_height",size=.75,valign="center"); // stroke(arc(r=3, cp=[0,-9], angle=[47,90],$fn=64),width=.15,endcaps="arrow2"); // move([-.5,-6])text("arm_angle", size=0.75,halign="right"); // move([14,-4])text("fill=true", size=1); // } // Continues: // As shown in the above figure, the fill option fills the gap between the hinge arm and the mount surface to make a stronger connection. When the // arm height is set to zero, only a single segment connects the hinge barrel to the mount surface. // Figure(2D,NoScales): Zero arm height with 45 deg arm // right(10) _hinge_profile(4, 0, $fn=32); // _hinge_profile(4, 0, $fn=32,fill=false); // right(11)fwd(-3)color("blue")text("fill=true",size=1); // right(.5)fwd(-3)color("blue")text("fill=false",size=1); // Continues: // Figure(2D,NoScales): Zero arm height with 90 deg arm. The clear_top parameter removes the hinge support material that is above the x axis // _hinge_profile(4, 0, 90, $fn=32); // right(10) _hinge_profile(4, 0, 90, $fn=32,clear_top=true); // right(9.5)fwd(-3)color("blue")text("clear_top=true",size=.76); // right(.5)fwd(-3)color("blue")text("clear_top=false",size=.76); // Continues: // For 3D printability, you may want to make the hinge pin hole octagonal. To do this without // changing the other parts of the design, set `pin_fn=8`. You can round off the joint to the // mount surface with `round_top` and `round_bot`. You specify the amount of thickness to add. // If you make this parameter too large you will get an error that the rounding doesn't fit. // The default pin hole size admits a piece of 1.75 mm filament. If you prefer to use a machine // screw you can set the pin_diam to a screw specification like `"M3"` or "#6". In this case, // a clearance hole is created through most of the hinge with a self-tap hole for the last segment. // If the last segment is very long you may shrink the self-tap portion using the tap_depth parameter. // The pin hole diameter is enlarged by the `2*$slop` for numerically specified holes. // Screw holes are made using {{screw_hole()} which enlarges the hole by `4*$slop`. // Arguments: // length = total length of the entire hinge // offset = horizontal offset of the hinge pin center from the mount point // segs = number of hinge segments // inner = set to true for the "inner" hinge. Default: false // --- // arm_height = vertical height of the arm that holds the hinge barrel. Default: 0 // arm_angle = angle of the arm down from the vertical. Default: 45 // fill = if true fill in space between arm and mount surface. Default: true // clear_top = if true remove any excess arm geometry that appears above the top of the mount surface. Default: false // gap = gap between hinge segments. Default: 0.2 // round_top = rounding amount to add where top of hinge arm joins the mount surface. Generally only useful when fill=false. Default: 0 // round_bot = rounding amount to add where bottom of hinge arm joins the mount surface. Default: 0 // knuckle_diam = diameter of hinge barrel. Default: 4 // pin_diam = diameter of hinge pin hole as a number of screw specification. Default: 1.75 // screw_head = screw head to use for countersink // screw_tolerance = screw hole tolerance. Default: "close" // tap_depth = Don't make the tapped part of the screw hole larger than this. // $slop = increases pin hole diameter // anchor = Translate so anchor point is at origin (0,0,0). See [anchor](attachments.scad#subsection-anchor). Default: `BOTTOM` // spin = Rotate this many degrees around the Z axis after anchor. See [spin](attachments.scad#subsection-spin). Default: `0` // orient = Vector to rotate top towards, after spin. See [orient](attachments.scad#subsection-orient). Default: `UP` // Example: Basic hinge, inner=false in front and inner=true in the back // $fn=32; // ydistribute(30){ // knuckle_hinge(length=35, segs=4, offset=3, arm_height=1); // knuckle_hinge(length=35, segs=4, offset=3, arm_height=1,inner=true); // } // Example(NoScales): Basic hinge, mounted. Odd segment count means the "outside" hinge is on the outside at both ends. // $fn=32; // cuboid([2,40,15]) // position(TOP+RIGHT) orient(anchor=RIGHT) // knuckle_hinge(length=35, segs=9, offset=3, arm_height=1); // Example(NoScales): Corresponding inner hinge to go with previous example. Note that the total number of hinge segments adds to the 9 specified. // $fn=32; // cuboid([2,40,15]) // position(TOP+RIGHT) orient(anchor=RIGHT) // knuckle_hinge(length=35, segs=9, offset=3, arm_height=1, inner=true); // Example(NoScales): This example shows how to position and orient the hinge onto the front of an object instead of the right side. // $fn=32; // cuboid([40,2,15]) // position(TOP+FRONT) orient(anchor=FWD) // knuckle_hinge(length=35, segs=9, offset=3, arm_height=1); // Example(NoScales): Hinge with round_bot set to create a smooth transition, but octagonal hinge pin holes for printing // $fn=32; // cuboid([2,40,15]) // position(TOP+RIGHT) orient(anchor=RIGHT) // knuckle_hinge(length=35, segs=9, offset=3, arm_height=1, // round_bot=1, pin_fn=8); // Example(NoScales): Hinge with no vertical arm, just angled arm // $fn=32; // cuboid([2,40,15]) // position(TOP+RIGHT) orient(anchor=RIGHT) // knuckle_hinge(length=35, segs=9, offset=3, pin_fn=8); // Example(NoScales): Setting the arm_angle to a large value like 90 produces a hinge that doesn't look great // $fn=32; // cuboid([2,40,15]) // position(TOP+RIGHT) orient(anchor=RIGHT) // knuckle_hinge(length=35, segs=9, offset=3, arm_angle=90, // arm_height=0, pin_fn=8); // Example(NoScales): The above hinge is improved with clear_top, which allows nice attachment to a shape half the thickness of the hinge barrel // $fn=32; // cuboid([20,40,2]) // position(TOP+RIGHT) orient(anchor=RIGHT) // knuckle_hinge(length=35, segs=9, offset=3, arm_height=0, // arm_angle=90, pin_fn=8, clear_top=true); // Example(NoScales): Uneven hinge using seg_ratio. Here the inner hinge segments are 1/3 the outer, a rather extreme difference. Note also that it's a little simpler to mount the inner hinge on the LEFT side of the top section to interface with the hinge mounted on the RIGHT. // $fn=32; // cuboid([2,40,15]){ // position(TOP+RIGHT) orient(anchor=RIGHT) // knuckle_hinge(length=35, segs=9, offset=3, arm_height=1, // seg_ratio=1/3); // attach(TOP,TOP) color("green") // cuboid([2,40,15],anchor=TOP) // position(TOP+LEFT) orient(anchor=LEFT) // knuckle_hinge(length=35, segs=9, offset=3, arm_height=1, // seg_ratio=1/3, inner=true); // } // Example(NoScales): A single hinge with an even number of segments will probably look strange, but they work together neatly in a pair. This example also shows that the arm_height can change between the inner and outer hinge parts and they will still interface properly. // $fn=32; // cuboid([2,40,15]){ // yflip_copy() // position(TOP+RIGHT+FRONT) orient(anchor=RIGHT) // knuckle_hinge(length=12, segs=2, offset=2, arm_height=2, // anchor=BOT+LEFT); // attach(TOP,TOP) color("green") // cuboid([2,40,15],anchor=TOP) // yflip_copy() // position(TOP+LEFT+FRONT) orient(anchor=LEFT) // knuckle_hinge(length=12, segs=2, offset=2, arm_height=0, // inner=true, anchor=BOT+RIGHT); // } // Example(NoScales): Hinge with self-tapping screw hole. Note that last segment has smaller diameter for screw to bite, whereas other segments have clearance holes. // $fn=32; // bottom_half(z=.01) // cuboid([2,40,15],anchor=TOP) // position(TOP+RIGHT) orient(anchor=RIGHT) // knuckle_hinge(length=35, segs=5, offset=5, knuckle_diam=9, pin_diam="#6", fill=false,inner=false, screw_head="flat"); // Example(NoScales): If you give a non-flat screw head then a counterbore for that head is generated. If you don't want the counterbore, don't give a head type. In this example, tap_depth limits the narrower self-tap section of the hole. // $fn=32; // bottom_half(z=.01) // cuboid([2,40,15],anchor=TOP) // position(TOP+RIGHT) orient(anchor=RIGHT) // knuckle_hinge(length=35, segs=3, offset=5, knuckle_diam=9, pin_diam="#6", // fill=false, inner=false, tap_depth=6, screw_head="socket"); function knuckle_hinge(length, offset, segs, inner=false, arm_height=0, arm_angle=45, gap=0.2, seg_ratio=1, knuckle_diam=4, pin_diam=1.75, fill=true, clear_top=false, round_bot=0, round_top=0, pin_fn, tap_depth, screw_head, screw_tolerance="close", anchor=BOT,orient,spin) = no_function("hinge"); module knuckle_hinge(length, offset, segs, inner=false, arm_height=0, arm_angle=45, gap=0.2, seg_ratio=1, knuckle_diam=4, pin_diam=1.75, fill=true, clear_top=false, round_bot=0, round_top=0, pin_fn, tap_depth, screw_head, screw_tolerance="close", anchor=BOT,orient,spin) { dummy = assert(is_str(pin_diam) || all_positive([pin_diam]), "pin_diam must be a screw spec string or a positive number") assert(all_positive(length), "length must be a postive number") assert(is_int(segs) && segs>=1, "segs must be an integer 1 or greater") assert(is_finite(offset) && offset>=knuckle_diam/2, "offset must be a valid number that is not smaller than radius of the hinge barrel") assert(is_finite(arm_angle) && arm_angle>0 && arm_angle<=90, "arm_angle must be greater than zero and less than or equal to 90"); segs1 = ceil(segs/2); segs2 = floor(segs/2); seglen1 = gap + (length-(segs-1)*gap) / (segs1 + segs2*seg_ratio); seglen2 = gap + (length-(segs-1)*gap) / (segs1 + segs2*seg_ratio) * seg_ratio; z_adjust = segs%2==1 ? 0 : inner? seglen1/2 : seglen2/2; attachable(anchor,spin,orient, size=[length, arm_height+offset/tan(arm_angle)+knuckle_diam/2+knuckle_diam/2/sin(arm_angle), offset+knuckle_diam/2], offset=[0, -arm_height/2-offset/tan(arm_angle)/2-knuckle_diam/sin(arm_angle)/4+knuckle_diam/4, -offset/2+knuckle_diam/4] ) { down(offset) yrot(-90) zmove(z_adjust) difference() { zcopies(n=inner?segs2:segs1, spacing=seglen1+seglen2) linear_extrude((inner?seglen2:seglen1)-gap,center=true) _hinge_profile(offset=offset, arm_height=arm_height, arm_angle=arm_angle, knuckle_diam=knuckle_diam, pin_diam=pin_diam, fill=fill, clear_top=clear_top, round_bot=round_bot, round_top=round_top, pin_fn=pin_fn); if (is_str(pin_diam)) right(offset) up(length/2-(inner?1:1)*z_adjust){ tap_depth = min(segs%2==1?seglen1-gap/2:seglen2-gap/2, default(tap_depth, length)); screw_hole(pin_diam, length=length+.01, tolerance="self tap", bevel=false, anchor=TOP); multmatrix(inner ? zflip(z=-length/2) : IDENT) if (is_undef(screw_head) || screw_head=="none" || starts_with(screw_head,"flat")) screw_hole(pin_diam, length=length-tap_depth, tolerance=screw_tolerance, bevel=false, anchor=TOP, head=screw_head); else { screw_hole(pin_diam, length=length-tap_depth, tolerance=screw_tolerance, bevel=false, anchor=TOP); screw_hole(pin_diam, length=.01, tolerance=screw_tolerance, bevel=false, anchor=TOP, head=screw_head); } } } children(); } } module _hinge_profile(offset, arm_height, arm_angle=45, knuckle_diam=4, pin_diam=1.75, fill=true, clear_top=false, round_bot=0, round_top=0, pin_fn) { extra = .01; skel = turtle(["left", 90-arm_angle, "untilx", offset+extra, "left", arm_angle, if (arm_height>0) each ["move", arm_height]]); ofs = arm_height+offset/tan(arm_angle); start=round_bot==0 && round_top==0 ? os_flat(abs_angle=90) : os_round(abs_angle=90, cut=[-round_top,-round_bot],k=.8); difference(){ union(){ difference(){ fwd(ofs){ left(extra)offset_stroke(skel, width=knuckle_diam, start=start); if (fill) polygon([each skel,[-extra,ofs]]); } if (clear_top) left(.1) rect([offset+knuckle_diam,knuckle_diam+1],anchor=BOT+LEFT); } right(offset)ellipse(d=knuckle_diam,realign=true,circum=true); } if (is_num(pin_diam) && pin_diam>0) right(offset)ellipse(d=pin_diam+2*get_slop(), realign=true, circum=true, $fn=default(pin_fn,$fn)); } } // Module: living_hinge_mask() // Usage: // living_hinge_mask(l, thick, [layerheight=], [foldangle=], [hingegap=], [$slop=], [anchor=], [spin=], [orient=]) [ATTACHMENTS]; // Description: // Creates a mask to be differenced away from a plate to create a "live" hinge, where a thin layer of plastic holds two parts together. // Center the mask at the bottom of the part you want to make a hinge in. // The mask will leave hinge material `2*layerheight` thick on the bottom of the hinge. // Arguments: // l = Length of the hinge in mm. // thick = Thickness in mm of the material to make the hinge in. // --- // layerheight = The expected printing layer height in mm. // foldangle = The interior angle in degrees of the joint to be created with the hinge. Default: 90 // hingegap = Size in mm of the gap at the bottom of the hinge, to make room for folding. // $slop = Increase size of hinge gap by double this amount // anchor = Translate so anchor point is at origin (0,0,0). See [anchor](attachments.scad#subsection-anchor). Default: `CENTER` // spin = Rotate this many degrees around the Z axis. See [spin](attachments.scad#subsection-spin). Default: `0` // orient = Vector to rotate top towards. See [orient](attachments.scad#subsection-orient). Default: `UP` // Example: // living_hinge_mask(l=100, thick=3, foldangle=60); module living_hinge_mask(l, thick, layerheight=0.2, foldangle=90, hingegap=undef, anchor=CENTER, spin=0, orient=UP) { hingegap = default(hingegap, layerheight)+2*get_slop(); size = [l, hingegap, 2*thick]; size2 = [l, hingegap+2*thick*tan(foldangle/2)]; attachable(anchor,spin,orient, size=size, size2=size2) { up(layerheight*2) prismoid([l,hingegap], [l, hingegap+2*thick/tan(foldangle/2)], h=thick, anchor=BOT); children(); } } module folding_hinge_mask(l, thick, layerheight=0.2, foldangle=90, hingegap=undef, anchor=CENTER, spin=0, orient=UP) { deprecate("living_hinge_mask"); living_hinge_mask(l, thick, layerheight, foldangle, hingegap, anchor, spin, orient); } // Section: Snap Locks // Module: apply_folding_hinges_and_snaps() // Usage: // apply_folding_hinges_and_snaps(thick, [foldangle=], [hinges=], [snaps=], [sockets=], [snaplen=], [snapdiam=], [hingegap=], [layerheight=], [$slop=]) CHILDREN; // Description: // Adds snaplocks and create hinges in children at the given positions. // Arguments: // thick = Thickness in mm of the material to make the hinge in. // foldangle = The interior angle in degrees of the joint to be created with the hinge. Default: 90 // hinges = List of [LENGTH, POSITION, SPIN] for each hinge to difference from the children. // snaps = List of [POSITION, SPIN] for each central snaplock to add to the children. // sockets = List of [POSITION, SPIN] for each outer snaplock sockets to add to the children. // snaplen = Length of locking snaps. // snapdiam = Diameter/width of locking snaps. // hingegap = Size in mm of the gap at the bottom of the hinge, to make room for folding. // layerheight = The expected printing layer height in mm. // --- // $slop = increase hinge gap by twice this amount // Example(Med): // size=100; // apply_folding_hinges_and_snaps( // thick=3, foldangle=54.74, // hinges=[ // for (a=[0,120,240], b=[-size/2,size/4]) each [ // [200, polar_to_xy(b,a), a+90] // ] // ], // snaps=[ // for (a=[0,120,240]) each [ // [rot(a,p=[ size/4, 0 ]), a+90], // [rot(a,p=[-size/2,-size/2.33]), a-90] // ] // ], // sockets=[ // for (a=[0,120,240]) each [ // [rot(a,p=[ size/4, 0 ]), a+90], // [rot(a,p=[-size/2, size/2.33]), a+90] // ] // ] // ) { // $fn=3; // difference() { // cylinder(r=size-1, h=3); // down(0.01) cylinder(r=size/4.5, h=3.1, spin=180); // down(0.01) for (a=[0:120:359.9]) zrot(a) right(size/2) cylinder(r=size/4.5, h=3.1); // } // } module apply_folding_hinges_and_snaps(thick, foldangle=90, hinges=[], snaps=[], sockets=[], snaplen=5, snapdiam=5, hingegap=undef, layerheight=0.2) { hingegap = default(hingegap, layerheight)+2*get_slop(); difference() { children(); for (hinge = hinges) { translate(hinge[1]) { living_hinge_mask( l=hinge[0], thick=thick, layerheight=layerheight, foldangle=foldangle, hingegap=hingegap, spin=hinge[2] ); } } } for (snap = snaps) { translate(snap[0]) { snap_lock( thick=thick, snaplen=snaplen, snapdiam=snapdiam, layerheight=layerheight, foldangle=foldangle, hingegap=hingegap, spin=snap[1] ); } } for (socket = sockets) { translate(socket[0]) { snap_socket( thick=thick, snaplen=snaplen, snapdiam=snapdiam, layerheight=layerheight, foldangle=foldangle, hingegap=hingegap, spin=socket[1] ); } } } // Module: snap_lock() // Usage: // snap_lock(thick, [snaplen=], [snapdiam=], [layerheight=], [foldangle=], [hingegap=], [$slop=], [anchor=], [spin=], [orient=]) [ATTACHMENTS]; // Description: // Creates the central snaplock part. // Arguments: // thick = Thickness in mm of the material to make the hinge in. // --- // snaplen = Length of locking snaps. // snapdiam = Diameter/width of locking snaps. // layerheight = The expected printing layer height in mm. // foldangle = The interior angle in degrees of the joint to be created with the hinge. Default: 90 // hingegap = Size in mm of the gap at the bottom of the hinge, to make room for folding. // $slop = increase size of hinge gap by double this amount // anchor = Translate so anchor point is at origin (0,0,0). See [anchor](attachments.scad#subsection-anchor). Default: `CENTER` // spin = Rotate this many degrees around the Z axis. See [spin](attachments.scad#subsection-spin). Default: `0` // orient = Vector to rotate top towards. See [orient](attachments.scad#subsection-orient). Default: `UP` // Example: // snap_lock(thick=3, foldangle=60); module snap_lock(thick, snaplen=5, snapdiam=5, layerheight=0.2, foldangle=90, hingegap=undef, anchor=CENTER, spin=0, orient=UP) { hingegap = default(hingegap, layerheight)+2*get_slop(); snap_x = (snapdiam/2) / tan(foldangle/2) + (thick-2*layerheight)/tan(foldangle/2) + hingegap/2; size = [snaplen, snapdiam, 2*thick]; attachable(anchor,spin,orient, size=size) { back(snap_x) { cube([snaplen, snapdiam, snapdiam/2+thick], anchor=BOT) { attach(TOP) xcyl(l=snaplen, d=snapdiam, $fn=16); attach(TOP) xcopies(snaplen-snapdiam/4/3) xscale(0.333) sphere(d=snapdiam*0.8, $fn=12); } } children(); } } // Module: snap_socket() // Usage: // snap_socket(thick, [snaplen=], [snapdiam=], [layerheight=], [foldangle=], [hingegap=], [$slop=], [anchor=], [spin=], [orient=]) [ATTACHMENTS]; // Description: // Creates the outside snaplock socketed part. // Arguments: // thick = Thickness in mm of the material to make the hinge in. // --- // snaplen = Length of locking snaps. // snapdiam = Diameter/width of locking snaps. // layerheight = The expected printing layer height in mm. // foldangle = The interior angle in degrees of the joint to be created with the hinge. Default: 90 // hingegap = Size in mm of the gap at the bottom of the hinge, to make room for folding. // $slop = Increase size of hinge gap by double this amount // anchor = Translate so anchor point is at origin (0,0,0). See [anchor](attachments.scad#subsection-anchor). Default: `CENTER` // spin = Rotate this many degrees around the Z axis. See [spin](attachments.scad#subsection-spin). Default: `0` // orient = Vector to rotate top towards. See [orient](attachments.scad#subsection-orient). Default: `UP` // Example: // snap_socket(thick=3, foldangle=60); module snap_socket(thick, snaplen=5, snapdiam=5, layerheight=0.2, foldangle=90, hingegap=undef, anchor=CENTER, spin=0, orient=UP) { hingegap = default(hingegap, layerheight)+2*get_slop(); snap_x = (snapdiam/2) / tan(foldangle/2) + (thick-2*layerheight)/tan(foldangle/2) + hingegap/2; size = [snaplen, snapdiam, 2*thick]; attachable(anchor,spin,orient, size=size) { fwd(snap_x) { zrot_copies([0,180], r=snaplen+get_slop()) { diff("divot") cube([snaplen, snapdiam, snapdiam/2+thick], anchor=BOT) { attach(TOP) xcyl(l=snaplen, d=snapdiam, $fn=16); tag("divot") attach(TOP) left((snaplen+snapdiam/4/3)/2) xscale(0.333) sphere(d=snapdiam*0.8, $fn=12); } } } children(); } }