////////////////////////////////////////////////////////////////////// // LibFile: constants.scad // Constants for directions (used with anchoring), and for specifying line termination for // use with geometry.scad. // Includes: // include // FileGroup: Basic Modeling // FileSummary: Constants provided by the library // FileFootnotes: STD=Included in std.scad ////////////////////////////////////////////////////////////////////// // a value that the user should never enter randomly; // result of `dd if=/dev/random bs=32 count=1 |base64` : _UNDEF="LRG+HX7dy89RyHvDlAKvb9Y04OTuaikpx205CTh8BSI"; // Section: General Constants // Constant: $slop // Synopsis: The slop amount to make printed items fit closely. `0.0` by default. // Topics: Constants // Description: // A number of printers, particularly FDM/FFF printers, tend to be a bit sloppy in their printing. // This has made it so that some parts won't fit together without adding a bit of extra slop space. // That is what the `$slop` value is for. The value for this will vary from printer to printer. // By default, we use a value of 0.00 so that parts should fit exactly for resin and other precision // printers. This value is measured in millimeters. When making your own parts, you should add // `$slop` to both sides of a hole that another part is to fit snugly into. For a loose fit, add // `2*$slop` to each side. This should be done for both X and Y axes. The Z axis will require a // slop that depends on your layer height and bridging settings, and hole sizes. We leave that as // a more complicated exercise for the user. // . // Note that the slop value is accessed using the {{get_slop()}} function. This function provides // the default value of 0 if you have not set `$slop`. This approach makes it possible for you to // set `$slop` in your programs without experiencing peculiar OpenSCAD issues having to do with multiple // definitions of the variable. If you write code that uses `$slop` be sure to reference it using {{get_slop()}}. // DefineHeader(NumList): Calibration // Calibration: To calibrate the `$slop` value for your printer, follow this procedure: // Print the Slop Calibration part from the example below. // Take the long block and orient it so the numbers are upright, facing you. // Take the plug and orient it so that the arrow points down, facing you. // Starting with the hole with the largest number in front of it, insert the small end of the plug into the hole. // If you can insert and remove the small end of the plug from the hole without much force, then try again with the hole with the next smaller number. // Repeat step 5 until you have found the hole with the smallest number that the plug fits into without much force. // The correct hole should hold the plug when the long block is turned upside-down. // The number in front of that hole will indicate the `$slop` value that is ideal for your printer. // Remember to set that slop value in your scripts after you include the BOSL2 library: ie: `$slop = 0.15;` // Example(3D,Med): Slop Calibration Part. // min_slop = 0.00; // slop_step = 0.05; // holes = 8; // holesize = [15,15,15]; // height = 20; // gap = 5; // l = holes * (holesize.x + gap) + gap; // w = holesize.y + 2*gap; // h = holesize.z + 5; // diff("holes") // cuboid([l, w, h], anchor=BOT) { // for (i=[0:holes-1]) { // right((i-holes/2+0.5)*(holesize.x+gap)) { // s = min_slop + slop_step * i; // tag("holes") { // cuboid([holesize.x + 2*s, holesize.y + 2*s, h+0.2]); // fwd(w/2-1) xrot(90) linear_extrude(1.1) { // text( // text=format_fixed(s,2), // size=0.4*holesize.x, // halign="center", // valign="center" // ); // } // } // } // } // } // back(holesize.y*2.5) { // difference() { // union() { // cuboid([holesize.x+10, holesize.y+10, 15], anchor=BOT); // cuboid([holesize.x, holesize.y, 15+holesize.z], anchor=BOT); // } // up(3) fwd((holesize.y+10)/2) { // prismoid([holesize.x/2,1], [0,1], h=holesize.y-6); // } // } // } // Example(2D): Where to add `$slop` gaps. // $slop = 0.2; // difference() { // square([20,12],center=true); // back(3) square([10+2*$slop,11],center=true); // } // back(8) { // rect([15,5],anchor=FWD); // rect([10,8],anchor=BACK); // } // color("#000") { // arrow_path = [[5.1,6.1], [6.0,7.1], [8,7.1], [10.5,10]]; // xflip_copy() // stroke(arrow_path, width=0.3, endcap1="arrow2"); // xcopies(21) back(10.5) { // back(1.8) text("$slop", size=1.5, halign="center"); // text("gap", size=1.5, halign="center"); // } // } // Function: get_slop() // Synopsis: Returns the $slop value. // Topics: Slop // See Also: $slop // Usage: // slop = get_slop(); // Description: // Returns the current $slop value, or the default value if the user did not set $slop. // Always acess the `$slop` variable using this function. function get_slop() = is_undef($slop) ? 0 : $slop; // Constant: INCH // Synopsis: A constant containing the number of millimeters in an inch. `25.4` // Topics: Constants // Description: // The number of millimeters in an inch. // Example(2D): // square(2*INCH, center=true); // Example(3D): // cube([4,3,2.5]*INCH, center=true); INCH = 25.4; // Constant: IDENT // Synopsis: A constant containing the 3D identity transformation matrix. // Topics: Constants, Affine, Matrices, Transforms // See Also: ident() // Description: Identity transformation matrix for three-dimensional transforms. Equal to `ident(4)`. IDENT=ident(4); // Section: Directional Vectors // Vectors useful for `rotate()`, `mirror()`, and `anchor` arguments for `cuboid()`, `cyl()`, etc. // Constant: LEFT // Synopsis: The left-wards (X-) direction vector constant `[-1,0,0]`. // Topics: Constants, Vectors // See Also: RIGHT, FRONT, BACK, UP, DOWN, CENTER // Description: Vector pointing left. [-1,0,0] // Example(3D): Usage with `anchor` // cuboid(20, anchor=LEFT); LEFT = [-1, 0, 0]; // Constant: RIGHT // Synopsis: The right-wards (X+) direction vector constant `[1,0,0]`. // Topics: Constants, Vectors // See Also: LEFT, FRONT, BACK, UP, DOWN, CENTER // Description: Vector pointing right. [1,0,0] // Example(3D): Usage with `anchor` // cuboid(20, anchor=RIGHT); RIGHT = [ 1, 0, 0]; // Constant: FRONT // Aliases: FWD, FORWARD // Synopsis: The front-wards (Y-) direction vector constant `[0,-1,0]`. // Topics: Constants, Vectors // See Also: LEFT, RIGHT, BACK, UP, DOWN, CENTER // Description: Vector pointing forward. [0,-1,0] // Example(3D): Usage with `anchor` // cuboid(20, anchor=FRONT); FRONT = [ 0, -1, 0]; FWD = FRONT; FORWARD = FRONT; // Constant: BACK // Synopsis: The back-wards (Y+) direction vector constant `[0,1,0]`. // Topics: Constants, Vectors // See Also: LEFT, RIGHT, FRONT, UP, DOWN, CENTER // Description: Vector pointing back. [0,1,0] // Example(3D): Usage with `anchor` // cuboid(20, anchor=BACK); BACK = [ 0, 1, 0]; // Constant: BOTTOM // Aliases: BOT, DOWN // Synopsis: The down-wards (Z-) direction vector constant `[0,0,-1]`. // Topics: Constants, Vectors // See Also: LEFT, RIGHT, FRONT, BACK, UP, CENTER // Description: Vector pointing down. [0,0,-1] // Example(3D): Usage with `anchor` // cuboid(20, anchor=BOTTOM); BOTTOM = [ 0, 0, -1]; BOT = BOTTOM; DOWN = BOTTOM; // Constant: TOP // Aliases: UP // Synopsis: The top-wards (Z+) direction vector constant `[0,0,1]`. // Topics: Constants, Vectors // See Also: LEFT, RIGHT, FRONT, BACK, DOWN, CENTER // Description: Vector pointing up. [0,0,1] // Example(3D): Usage with `anchor` // cuboid(20, anchor=TOP); TOP = [ 0, 0, 1]; UP = TOP; // Constant: CENTER // Aliases: CTR, CENTRE // Synopsis: The center vector constant `[0,0,0]`. // Topics: Constants, Vectors // See Also: LEFT, RIGHT, FRONT, BACK, UP, DOWN // Description: Zero vector. Centered. [0,0,0] // Example(3D): Usage with `anchor` // cuboid(20, anchor=CENTER); CENTER = [ 0, 0, 0]; // Centered zero vector. CTR = CENTER; CENTRE = CENTER; // Section: Line specifiers // Used by functions in geometry.scad for specifying whether two points // are treated as an unbounded line, a ray with one endpoint, or a segment // with two endpoints. // Constant: SEGMENT // Synopsis: A constant for specifying a line segment in various geometry.scad functions. `[true,true]` // Topics: Constants, Lines // See Also: RAY, LINE // Description: Treat a line as a segment. [true, true] // Example: Usage with line_intersection: // line1 = 10*[[9, 4], [5, 7]]; // line2 = 10*[[2, 3], [6, 5]]; // isect = line_intersection(line1, line2, SEGMENT, SEGMENT); SEGMENT = [true,true]; // Constant: RAY // Synopsis: A constant for specifying a ray line in various geometry.scad functions. `[true,false]` // Topics: Constants, Lines // See Also: SEGMENT, LINE // Description: Treat a line as a ray, based at the first point. [true, false] // Example: Usage with line_intersection: // line = [[-30,0],[30,30]]; // pt = [40,25]; // closest = line_closest_point(line,pt,RAY); RAY = [true, false]; // Constant: LINE // Synopsis: A constant for specifying an unbounded line in various geometry.scad functions. `[false,false]` // Topics: Constants, Lines // See Also: RAY, SEGMENT // Description: Treat a line as an unbounded line. [false, false] // Example: Usage with line_intersection: // line1 = 10*[[9, 4], [5, 7]]; // line2 = 10*[[2, 3], [6, 5]]; // isect = line_intersection(line1, line2, LINE, SEGMENT); LINE = [false, false]; // vim: expandtab tabstop=4 shiftwidth=4 softtabstop=4 nowrap