[User]
Hey, I'm looking for an OpenSCAD design for a drain strainer, something I can customize for different sink sizes. I've got a pretty clear idea of what I need.

Essentially, it's got three main parts: the drain sleeve that fits into the drain, the actual strainer itself with holes, and then a skirt that sits on the sink surface.

For the drain sleeve, I want to be able to specify the diameter and depth, as well as the sleeve thickness so it fits snugly in the drain opening. The strainer part should have a grid pattern, which can either be squares or circles (user selectable), and I'd need to be able to set the dimensions of those holes, as well as the spacing between them. For the skirt, it should have a flat top, with a smaller bottom that fits over the outside of the drain sleeve, and I'd like to adjust the diameters and thickness of it. Oh, and I need to be able to adjust how far it sits above the top of the drain sleeve; I'll probably want to vary that based on the lip of whatever sink I use.

I’d like to be able to specify the following parameters:

**Strainer:**
*   `strainer_type`:  "square" or "circle" to switch between different hole styles.
*   `strainer_x_mm`: the width of the squares, or diameter of the circles.
*   `strainer_y_mm`: the height of the squares (only applicable when `strainer_type` is "square").
*   `strainer_thickness_mm`: how thick the actual strainer part is.
*   `strainer_grid_spacing_mm`: the space between the holes/squares.

**Drain:**
*   `drain_diameter_mm`: the diameter of the drain.
*   `drain_depth_mm`: the depth of the drain.
*   `drain_sleeve_thickness`: the thickness of the sleeve that fits into the drain.

**Skirt:**
*   `skirt_diameter_mm`: the outer diameter of the skirt.
*   `skirt_upper_diameter_mm`: the inner diameter where the skirt meets the drain sleeve.
*   `skirt_thickness_mm`: the thickness of the skirt.

**Hidden:**
*   `skirt_z_offset`:  The z-offset to determine where the skirt sits on the drain sleeve, should be equal to `drain_depth_mm - skirt_thickness_mm`, but I want it exposed so I can set it manually if needed.
*   `circle_strainer_resolution`:  Resolution setting for circles
*    `drain_sleeve_difference`: Calculated `drain_sleeve_thickness * 2`, but I want it exposed.

I am looking for a single OpenSCAD file, or a small number of files (e.g., one for each module) that I can easily customize using these parameters.  I don’t need to use any external libraries. Let me know if you need more information!

[Assistant]
strainer.scad:
```
// Drain Strainer
// by Nathan Wittstock <nate@fardog.io>

// preview[view: south east, tilt: top diagonal]

/* [Strainer] */
strainer_type = "square"; // [square: Square,circle: Circle]
strainer_x_mm = 3.0; //[1.0:10.0]
strainer_y_mm = 3.0; //[1.0:10.0]
strainer_thickness_mm = 1.0; //[1.0:3.0]
strainer_grid_spacing_mm = 2.0; //[0.5:3.0]

/* [Drain] */
drain_diameter_mm = 42.5; //[5.0:150.0]
drain_depth_mm = 10.0; //[0.0:50.0]
drain_sleeve_thickness = 1.0; //[0.5:3.0]

/* [Skirt] */
skirt_diameter_mm = 52.5; //[5.0:200.0]
skirt_upper_diameter_mm = 48.5; //[5.0:200.0]
skirt_thickness_mm = 2.0; //[1.0:3.0]

/* [Hidden] */
skirt_z_offset = drain_depth_mm - skirt_thickness_mm;
circle_strainer_resolution = 10;
drain_sleeve_difference = drain_sleeve_thickness * 2;

module drain_sleeve() {
    difference() {
        cylinder(h=drain_depth_mm, d=drain_diameter_mm);
        cylinder(h=drain_depth_mm, d=drain_diameter_mm-drain_sleeve_difference);
    }
}

module strainer_square() {
    x_size = strainer_x_mm + strainer_grid_spacing_mm;
    x_total = ceil(drain_diameter_mm / x_size) * x_size;
    x_offset = (x_total - strainer_grid_spacing_mm) / 2;
    y_size = strainer_y_mm + strainer_grid_spacing_mm;
    y_total = ceil(drain_diameter_mm / y_size) * y_size;
    y_offset = (y_total - strainer_grid_spacing_mm) / 2;

    translate([-x_offset, -y_offset, 0]) {
        for (x = [0:x_size:drain_diameter_mm]) {
            translate([x,0,0])
            for (y = [0:y_size:drain_diameter_mm]) {
                translate([0, y, 0])
                    cube([strainer_x_mm, strainer_y_mm, strainer_thickness_mm]);
            }
        }
    }
}

module strainer_circle() {
    x_size = strainer_x_mm + strainer_grid_spacing_mm;
    x_total = ceil(drain_diameter_mm / x_size) * x_size;
    x_offset = (x_total) / 2;
    y_size = strainer_y_mm + strainer_grid_spacing_mm;
    y_total = ceil(drain_diameter_mm / y_size) * y_size;
    y_offset = (y_total) / 2;

    translate([-x_offset, -y_offset, 0]) {
        for (x = [0:x_size:drain_diameter_mm]) {
            translate([x,0,0])
            for (y = [0:y_size:drain_diameter_mm]) {
                translate([0, y, 0])
                    cylinder(h=strainer_thickness_mm, d=strainer_x_mm, $fn=circle_strainer_resolution);
            }
        }
    }
}

module strainer() {
    union() {
        difference() {
            cylinder(h=strainer_thickness_mm, d=drain_diameter_mm);
            cylinder(h=strainer_thickness_mm, d=drain_diameter_mm-drain_sleeve_difference);
        }
        difference() {
            cylinder(h=strainer_thickness_mm, d=drain_diameter_mm);

            if (strainer_type == "square") {
                strainer_square();
            } else if (strainer_type == "circle") {
                strainer_circle();
            }
        }
    }
}

module skirt() {
    difference() {
        cylinder(h=skirt_thickness_mm, d1=skirt_diameter_mm, d2=skirt_upper_diameter_mm);
        cylinder(h=skirt_thickness_mm, d=drain_diameter_mm);
    }
}

union() {
    drain_sleeve();
    strainer();
    translate([0, 0, skirt_z_offset])
        skirt();
}

```


[User]
I'd like to design a parametric storage box with a lid. I'm envisioning something similar to the design I found on Thingiverse by dector, but I want to make sure it's completely flexible for my specific needs.

Here's what I need:

*   **Cells:** The box should be divided into a grid of cells. I need to be able to specify both the dimensions of each cell and how many cells to have in each direction (x and y). Think of the `cellSize` and `cellsCount` parameters from the example.
*   **Thicknesses:** I need to control the thickness of the walls: the inner walls between the cells, the outer walls of the box, and the bottom of the box. These are similar to `innerThickness`, `outerThickness`, and `bottomThickness`.
*   **Lid/Cover:** I'd like a separate lid that fits over the box. The lid should have its own thickness that I can adjust (like the `coverThickness` in the example). I also need to control how much the lid overlaps the box and a small gap to make sure the fit isn't too tight, just like with the example's `coverOverlap` and `coverGap`.
*   **Parametric:** I want to be able to adjust all of these parameters, so everything should be defined using variables that I can change easily, rather than hardcoding numbers. I'd like to be able to specify these parameters as vectors where applicable like the example.

Could you generate the necessary OpenSCAD files for this design? I don't need any specific libraries. I expect that everything will be written from scratch.

[Assistant]
StorageBox_all.scad:
```
/*
    Simple Parametric Storage Box by dector (https://www.thingiverse.com/thing:3177524)

    This version is optimized for Thingiverse Customizer.
    For full sources and latest version checkout github repository:

    https://github.com/dector/things/tree/master/StorageBox
*/

cellSize = [25, 30, 25];
cellsCount = [3, 1];

innerThickness = 1;
outerThickness = 1;
coverThickness = 1;
bottomThickness = 1;

coverOverlap = 2;
coverGap = 0.3;

$fa = 1;
$fs = 0.2;

// Utils

function boxXSize(count, size, innerThickness, outerThickness) = count * (size + innerThickness) - innerThickness + 2 * outerThickness;

function boxYSize(count, size, innerThickness, outerThickness) = count * (size + innerThickness) - innerThickness + 2 * outerThickness;

function boxZSize(size, bottomThickness) = bottomThickness + size;

module StorageBox(cellsCount, cellSize, innerThickness = innerThickness, outerThickness = outerThickness, bottomThickness = bottomThickness) {

    boxSize = [
        boxXSize(cellsCount.x, cellSize.x, innerThickness, outerThickness),
        boxYSize(cellsCount.y, cellSize.y, innerThickness, outerThickness),
        boxZSize(cellSize.z, bottomThickness)
    ];

    difference() {
        cube(boxSize);    // Outer bound

        union() {
            for (i = [1:cellsCount.x]) {
                for (j = [1:cellsCount.y]) {
                    x = outerThickness + (i-1) * (cellSize.x + innerThickness);
                    y = outerThickness + (j-1) * (cellSize.y + innerThickness);
                    z = bottomThickness;

                    translate([x, y, z]) cube([cellSize.x, cellSize.y, cellSize.z]);    // Cell
                }
            }
        }
    }
}

module Cover(boxSize, overlap = coverOverlap, gap = coverGap, thickness = coverThickness) {

    coverSize = [
        boxSize.x + 2*coverThickness + 2*coverGap,
        boxSize.y + 2*coverThickness + 2*coverGap,
        coverThickness + coverOverlap
    ];

    difference() {
        cube(coverSize);
        translate([thickness + gap, thickness + gap, thickness]) cube([boxSize.x, boxSize.y, coverOverlap]);
    }
}

// StorageBox
{
    StorageBox(cellsCount, cellSize);
}

// Cover
boxYSize = boxYSize(cellsCount.y, cellSize.y, innerThickness, outerThickness);
translate([0, boxYSize + 5, 0]) {
    boxSize = [
        boxXSize(cellsCount.x, cellSize.x, innerThickness, outerThickness),
        boxYSize
    ];
    Cover(boxSize);
}

```


[User]
I'd like a parametric OpenSCAD design for a hex nut driver, but I want a bit more flexibility than just the "tool" or "knob" distinction. I'm envisioning a modular system with three main parts: a handle, a socket insert for the hex nut, and optionally a shaft for attaching to something else.

For the handle, I need it to be able to have different shapes: I'd like a simple cylindrical version, and then also one that has a knurled surface for better grip. I’d like the handle to have parameters for diameter, length, and knurl density when knurled.

The socket insert will actually hold the nut. I'd like parameters for the nut size (width across flats), nut thickness, and a tolerance value to adjust for different printer accuracy and fit preferences. It also should have a depth parameter for how far into the handle it fits.

For the shaft, I need a simple cylindrical shape with parameters for diameter and length.

I want to be able to assemble these together as a full nut driver with a choice of handle type and presence/absence of the shaft. The final design should also allow for different mounting styles on the socket, like having a flush mount or a protruding lip to integrate better.

I'd like to be able to define the type of socket for each use, meaning I would specify the nut size, tolerance, depth, and mounting style for each instance. I’d like the final assembly to be configurable in such a way as to choose which handle style to use, whether or not to add a shaft, and use a given socket style with it.

I'm not looking for any pre-made code; I want this built completely parametrically so I can experiment with different combinations.

[Assistant]
nut_driver.scad:
```
// nut_driver.scad
// library for parametric nut drivers, knobs, handles or tools
// Author: Tony Z. Tonchev, Michigan (USA)
// last update: October 2018

// Nut driver or knob (in mm)
Type = 1; //[0:NUT DRIVER (OPEN),1:NUT DRIVER (CLOSED), 2:NUT KNOB, 3:NUT KNOB (REVERSED)]

// Knob diameter (in mm)
Wheel_Diameter = 40;

// Knob thickness (in mm)
Wheel_Width = 10;

// Nut size, width across flats (in mm)
Nut_Size = 9;

// Shaft/Bolt/Rod size (in mm)
Shaft_Size = 6;

// Nut size tolerance (in mm/10)
Nut_Tolerance = 6; //[0:9]

// Nut thickness (in mm)
Nut_Thickness = 6;

/* [Hidden] */

$fn=100;
difference () {
    TZT_Wheel (Wheel_Diameter/2, Wheel_Width, Nut_Size);
    TZT_Hole (Wheel_Width, Nut_Size+(.1*Nut_Tolerance), Nut_Thickness, Type, Shaft_Size/2);
}

module TZT_Hole (TZT_Wid, TZT_Drv, TZT_Thk, TZT_Typ, TZT_Sht) {
    union () {
        TZT_hex = (TZT_Drv / sqrt(3));
        if (TZT_Typ==0) {
            cylinder (TZT_Wid*2, TZT_hex, TZT_hex, true, $fn=6);
        }
        else if (TZT_Typ==1) {
            translate ([0,0,3]) {
                cylinder (TZT_Wid, TZT_hex, TZT_hex, true, $fn=6);
            }
        }
        else if (TZT_Typ==2) {
            cylinder (TZT_Wid+5, TZT_Drv/2.4, TZT_Drv/2.4, true);
            translate ([0,0,TZT_Wid/2-TZT_Thk+2]) {
                cylinder (TZT_Thk+1, TZT_hex, TZT_hex, $fn=6);
            }
        }
        else {
            cylinder (TZT_Wid+5, TZT_Sht, TZT_Sht, true);
            rotate ([0,180,0]) {
                translate ([0,0,TZT_Wid/2-TZT_Thk]) {
                    cylinder (TZT_Thk+1, TZT_hex, TZT_hex, $fn=6);
                }
            }
        }
    }
}
module TZT_Wheel (TZT_Rad, TZT_Wid, TZT_Drv) {
    difference () {
        union () {
            cylinder (TZT_Wid-2, TZT_Rad, TZT_Rad, true);
            for (TZT_i=[0:180:180]) {
                rotate ([0,TZT_i,0]) {
                    translate ([0,0,TZT_Wid/2-1]) {
                        cylinder (1, TZT_Rad, TZT_Rad-1);
                    }
                }
            }
            translate ([0,0,TZT_Wid/2]) {
                cylinder (2, TZT_Drv, TZT_Drv*.8);
            }
        }
        for (TZT_i = [0:30:330]) {
            rotate ([0, 0, TZT_i]) {
                translate ([TZT_Rad*1.15, 0, 0]) {
                    cylinder (TZT_Wid+1, TZT_Rad/4, TZT_Rad/4, true);
                }
            }
        }
    }
}
```


[User]
Hey, I'm looking to design a customizable Lego-style birthday card, and I'd like to use OpenSCAD to make it parametric. I've seen some cool designs out there, and I have a good idea of what I want.

Essentially, it should be a rectangular brick-like shape with studs on top, just like a Lego brick. I'd like to be able to control the following:

*   **Overall Dimensions:** I need to be able to specify the number of studs along the length (columns) and width (rows) of the card.
*   **Edge Studs:** I want to control how many studs are on each side (left/right) and the top/bottom edges. This is important for aesthetics, and so you'd need to make sure the studs are only generated on the edges based on those parameters.
*   **Brick Height:** The height should be adjustable, likely as a fraction of a standard Lego brick height. I want to be able to select from common Lego brick height ratios like 1/3 and 1.
*   **Scale:**  There should be a general scaling factor for the entire brick, potentially to allow for making smaller or larger bricks than standard ones.
*   **Text:** I want to be able to add multiple lines of text onto the surface of the card. The number of text lines should be adjustable, and the text itself should be customizable for each line. The text should be centered on the top surface of the brick.
*   **Font:**  I want to be able to choose from a variety of fonts. Maybe you could start with some common Google Fonts that work well within the OpenSCAD customizer interface. You'd need to handle including the font files somehow for custom fonts. I need to be able to adjust the font size.
*   **Curve Smoothness:** The number of facets for generating the cylinders used for the studs and internal structure. This should also be an option in the parameters, so I can make the curves smoother if needed.

For the internal structure, I'd like it to have the typical Lego-style hollowed-out interior with cylindrical support pegs. It should also have the small rectangular knob holder structures at the base.

I don't need any specific libraries other than the standard OpenSCAD features, so no need to include any library files or anything. Let me know if you need any more info or if you can put something together for me.

[Assistant]
brick-birthday-card.scad:
```
/*
   Parametric Lego Brick
   Andrew Sweet, 2014
   Feel free to use my design,
	credit is appreciated where appropriate

   If you choose to alter this code, please keep this
	top comment in all further iterations :)

   Modified to be able to print birthday cards (or other
   similar objects) by Andreas Ehliar.
*/

/* Parameters */

// This is the number of studs in one column of the birthday card
numCols = 18; // [10:30]

// This is the number of studs in one row of the birthday card
numRows = 10; // [6:30]

// This is the number of studs on the left and right side of the birthday card. 2 to 4 are typically good values.
studsOnSide = 2; // [0:8]

// This is the number of studs on the top and bottom side of the birthday card. 1 or 2 are typically good values.
studsOnTop = 1; // [0:8]

// 1/3 and 1 are the two standard heights. You should probably leave this at 1/3.
height = 1/3; // [0.33333333, 1]

// Multiples of 2 of each other can fit into each other. You should probably leave this at 1.
brickScale = 1; // [1, 2, 4, 0.5, 0.25]

// Number of text lines
numberOfTextLines = 2; // [1, 2, 3]

// Text on first line
textLine1 = "HAPPY";

// Text on second line
textLine2 = "BIRTHDAY";

// Text on third line
textLine3 = "";

// Fontsize
fontSize = 17; // [5:40]

// Font selection from Google Fonts which works well with the Customizer. For other fonts, you'll need to download the file yourself.
fontName = "Luckiest Guy"; // [Oswald, Bitter, Indie Flower, Lobster, Abril Fatface, Bree Serif, Righteous, Teko, Courgette, Satisfy, Caveat, Luckiest Guy, Tangerine, Bangers, Notable, Fugaz One, Knewave]

// The higher the number, the smoother the curves.
curveFidelity = 40; // [10:100]

/* End Parameters */

// See comments below if you want to modify the font!

/* Lego Dimensions courtesy of:

http://www.robertcailliau.eu/Lego/Dimensions/zMeasurements-en.xhtml

and

http://static2.wikia.nocookie.net/__cb20130331204917/legomessageboards/images/3/3c/Lego_brick_2x4.png

*/

/* [Hidden] */

// Brick Dimensions
brickHeightDim = 9.6; // toBeScaled

brickUnit = 8.0;

dWidth = 0.2;
brickWidth = ((brickUnit * numCols) - dWidth) * brickScale;
brickDepth = ((brickUnit * numRows)  - dWidth) * brickScale;

brickHeight = (height * brickHeightDim) * brickScale;

shellThicknessTop = 1.0 * brickScale;
shellThicknessSides = 1.2 * brickScale;

// UnderPeg
uPegMaxRadius = 6.51 * brickScale/2;
uPegMinRadius = 4.8 * brickScale/2;
uPegOffset    = (brickUnit - 0.1) * brickScale;
uPegHeight    = brickHeight - shellThicknessTop;

// Pegs
tempDistance = 2.4 + 1.6; // To be scaled
pegOffset    = (tempDistance - 0.1) * brickScale;
tempRadius   = 4.8 / 2.0;
pegDistance  = brickUnit * brickScale;

pegRadius   = tempRadius * brickScale;
pegHeight   = 1.8 * brickScale;

// KnobHolders (small rectangular protrusions underneath)
khWidth  = 0.6 * brickScale;
khDepth  = 0.3 * brickScale;
khOffset = shellThicknessSides + khDepth + pegRadius+ (0.1 * brickScale);

// Create the Brick

difference()
{
  cube([brickWidth, brickDepth, brickHeight]);

  translate([shellThicknessSides,
	     shellThicknessSides,
	     -1])
    cube([brickWidth - (shellThicknessSides * 2),
	  brickDepth - (shellThicknessSides * 2),
	  brickHeight - shellThicknessTop + 1]);
}

if (numCols > 1 && numRows > 1){
  /* Add Interior */
  for (row = [1:(numCols - 1)]){
    for (col = [1:(numRows - 1)]){

      // Cylinders
      translate([uPegOffset + (pegDistance * (row - 1)),
		 uPegOffset + (pegDistance * (col-1)),
		 0])
	render()
	difference()
	{
	  cylinder(h=uPegHeight,
		   r1=uPegMaxRadius,
		   r2=uPegMaxRadius, $fn=curveFidelity);
	  translate([0,0,-1])
	    cylinder(h=uPegHeight+0.999,
		     r1=uPegMinRadius,
		     r2=uPegMinRadius, $fn=curveFidelity);
	}
    }
  }
 } else {
  assign (rad = (pegDistance - (pegRadius * 2))/2 - (0.1 * brickScale))
    {
      if (numCols > 1){

	for (row = [1:(numCols - 1)]){
	  translate(
		    [uPegOffset + (pegDistance * (row - 1)),
		     (brickUnit * brickScale)/2,
		     0])
	    render()
	    cylinder(h=uPegHeight,
		     r1=rad,
		     r2=rad, $fn=curveFidelity);
	}

      } else if (numRows > 1){
	for (col = [1:(numRows - 1)]){
	  translate(
		    [(brickUnit * brickScale)/2,
		     uPegOffset + (pegDistance * (col - 1)),
		     0])
	    render()
	    cylinder(h=uPegHeight,
		     r1=rad,
		     r2=rad, $fn=curveFidelity);
	}
      }
    }
 }

// KnobHolders (underneath)
if (numCols > 1 && numRows > 1){
  for (row = [0:(numCols - 1)]){
    translate([khOffset + (pegDistance * row),
	       shellThicknessSides,
	       0])
      cube([khWidth, khDepth, uPegHeight]);

    translate([khOffset + (pegDistance * row),
	       (numRows * (brickUnit * brickScale)) - shellThicknessSides - khDepth - (0.2 * brickScale),
	       0])
      cube([khWidth, khDepth, uPegHeight]);
  }

  for (col = [0:(numRows - 1)]){
    translate([shellThicknessSides,
	       khOffset + (pegDistance * col),
	       0])
      cube([khDepth, khWidth, uPegHeight]);

    translate([(numCols * (brickUnit * brickScale)) - shellThicknessSides - khDepth - (0.2 * brickScale),
	       khOffset + (pegDistance * col),
	       0])
      cube([khDepth, khWidth, uPegHeight]);
  }
 }

// Create the Pegs
for (row = [0:(numCols - 1)]){
  for (col = [0:(numRows - 1)]){
    if((row < studsOnSide) || (row > numCols - studsOnSide - 1) ||
       (col < studsOnTop) || (col > numRows - studsOnTop - 1))
      translate([pegOffset + (pegDistance * row),
		 pegOffset + (pegDistance * col),
		 brickHeight])
	render()
	cylinder(h=pegHeight,
		 r1=pegRadius,
		 r2=pegRadius, $fn=curveFidelity);
  }
 }

brickDepthNoStuds = brickDepth * (numRows - studsOnTop * 2) / numRows;

lineOneOffset = numberOfTextLines == 1 ? brickDepth / 2 :
  (numberOfTextLines == 2 ? brickDepth / 2 + brickDepthNoStuds / 4 :
   brickDepth / 2 + brickDepthNoStuds / 6 * 2);

lineTwoOffset = (numberOfTextLines == 2) ? brickDepth / 2 - brickDepthNoStuds / 4:
   brickDepth / 2;

lineThreeOffset = brickDepth / 2 - brickDepthNoStuds / 6 * 2;

translate([brickWidth/2, lineOneOffset ,brickHeight-0.2]){
  linear_extrude(1+0.2){
    text(textLine1, font=fontName, size=fontSize, halign="center", valign="center", $fn=curveFidelity);
  }
}

if (numberOfTextLines >= 2) {
  translate([brickWidth/2, lineTwoOffset, brickHeight-0.2]){
    linear_extrude(1+0.2){
      text(textLine2, font=fontName, size=fontSize, halign="center", valign="center", $fn=curveFidelity);
    }
  }
}

if (numberOfTextLines >= 3) {
  translate([brickWidth/2, lineThreeOffset, brickHeight-0.2]){
    linear_extrude(1+0.2){
      text(textLine3, font=fontName, size=fontSize, halign="center", valign="center", $fn=curveFidelity);
    }
  }
}

```


[User]
I'd like to design a custom watch band, and I'd like to do it in OpenSCAD. I've seen some nice one-piece designs that use a flexible filament and work with standard spring bar attachments. I'm hoping you can help me generate the OpenSCAD files to do this, including making it parametric so I can adjust it for different watches and wrists.

Here's what I'm looking for in the design:

*   **One-piece construction:** The band should be a single continuous piece, designed to be printed in flexible filament.
*   **Spring bar compatibility:** It needs to be compatible with standard quick-release spring bars, including the pegs that connect to the watch.
*   **Parametric design:** I'd like to be able to adjust the following:
    *   `bandWidth`: The width of the band itself.
    *   `bandLength`: The total length of the band.
    *   `bandThickness`: The thickness of the band.
    *   `endDiameter`: The diameter of the circular ends where the spring bars attach.
    *   `pinDiameter`: The diameter of the spring bar pins.
    *   `windowOffset`: The distance from the edge of the band to the window opening for the peg.
    *   `windowHeight`: The height of the window opening for the spring bar peg.
    *   `chamfer`: A chamfer size for edges.
    *   `watchWearHand`: A setting for left (0) or right (1) hand wear, which affects the direction of the peg openings.
    *   `resolutionStrap`: Circle resolution for the main strap curvature.
*   **Comfort:** The band should have a comfortable shape, with rounded edges and a smooth transition between the band and the circular ends. I'd like it to use a curved shape for the body of the band, rather than a simple rectangle.
*   **Window Opening:** It should have a precise window opening for the spring bar peg on each end of the band, placed appropriately based on the watchWearHand parameter.
*   **Holes for Spring Bars:** It should generate the correct sized holes to accommodate the spring bars.
*   **Trimmed Ends:** The band should have trimmed ends, ensuring a smooth, clean finish on the band.

I would like the design to be entirely parametric, so I can just change those variables. I'm not looking for any specific libraries at the moment. Could you provide me with a single OpenSCAD file to accomplish this?

[Assistant]
One_piece_watch_band_2015.scad:
```
/* One-piece Watch band by Ryan Huang, written on 28/10/2018, Thingiverse ID: yyh1002
*/

//width of the watch band
bandWidth = 20;

//length of band
bandLength = 145;

//thickness of band
bandThickness = 1.2;

//diameter of the ends of band
endDiameter = 4.3;

//diameter of the pins
pinDiameter = 2;

//distance between the edge of window opening for peg and the edge of band
windowOffset = 2.4;

//height of the window opening for pins
windowHeight = 3;

//chamfer size
chamfer = 0.2;

//wear hand of watch
watchWearHand = 0; //[0:left, 1:right]

//circle resolution of band strap
resolutionStrap = 192;

//circle resolution of ends
$fn=24;

bandRadius = bandLength*0.212;

filletAngle = 90*(bandThickness/endDiameter);

filletRadius = 1*bandRadius*(bandThickness/endDiameter)*(bandThickness/endDiameter)+1*endDiameter/2;

strapProfilePts = [
    [-bandThickness/2-chamfer,0],
    [-chamfer,0],
    [0,chamfer],
    [0,bandWidth-chamfer],
    [-chamfer,bandWidth],
    [-bandThickness+chamfer,bandWidth],
    [-bandThickness,bandWidth-chamfer],
    [-bandThickness,chamfer],
    ];

endProfilePts = [
    [pinDiameter/2,0],
    [endDiameter/2-chamfer,0],
    [endDiameter/2,chamfer],
    [endDiameter/2,bandWidth-chamfer],
    [endDiameter/2-chamfer,bandWidth],
    [pinDiameter/2,bandWidth],
    ];

trimPts = [
    [-chamfer,0],
    [0,chamfer],
    [0,bandWidth-chamfer],
    [-chamfer,bandWidth],
    [2*bandRadius,bandWidth],
    [2*bandRadius,0],
    ];

module teardrop_flat(diameter) {
	union() {
		circle(r = diameter/2, $fn = 100, center=true);
		rotate(45) square(diameter/2);
	}
}

module cross_section(diameter, thickness) {
	difference() {
		teardrop_flat(diameter);
		teardrop_flat(diameter - thickness*2);
		translate([0,-diameter/2,0]) square([diameter*2,diameter], center=true);
	}
}

module pie_slice(radius, angle, step) {
	for(theta = [0:step:angle-step]) {
		rotate([0,0,0])
		linear_extrude(height = bandWidth*2, center=true)
		polygon(
			points = [
				[0,0],
				[radius * cos(theta+step) ,radius * sin(theta+step)],
				[radius*cos(theta),radius*sin(theta)]
			]
		);
	}
}

module partial_rotate_extrude(angle, radius, convex) {
	intersection () {
		rotate_extrude(convexity=convex) translate([radius,0,0]) child(0);
		pie_slice(radius*2, angle, angle/5);
	}
}

module bandMesh(){
union() {
partial_rotate_extrude(270, bandRadius, $fn=resolutionStrap)
    polygon( strapProfilePts );
/*
translate([bandRadius-endDiameter/2,0,0])
    partial_rotate_extrude(-270+filletAngle, endDiameter/2)
        polygon( strapProfilePts );
*/
translate([bandRadius-endDiameter/2-(filletRadius+endDiameter/2)*sin(filletAngle),(filletRadius+endDiameter/2)*cos(filletAngle),0])
    rotate([0,0,-90+filletAngle])
        partial_rotate_extrude(90-1*filletAngle, filletRadius+bandThickness)
        polygon( strapProfilePts );
/*
translate([0,-bandRadius+endDiameter/2,0])
    rotate([0,0,-90])
        partial_rotate_extrude(270-filletAngle, endDiameter/2)
        polygon( strapProfilePts );
*/
translate([-(filletRadius+endDiameter/2)*cos(filletAngle),-bandRadius+endDiameter/2+(filletRadius+endDiameter/2)*sin(filletAngle),0])
    rotate([0,0,-filletAngle])
        partial_rotate_extrude(-90+1*filletAngle, filletRadius+bandThickness)
        polygon( strapProfilePts );
translate([bandRadius-endDiameter/2,0,0])
    rotate_extrude()
        polygon( endProfilePts );
translate([0,-bandRadius+endDiameter/2,0])
    rotate_extrude()
        polygon( endProfilePts );
}
}

module windowOpeningProfile(){
linear_extrude(endDiameter/2)
union(){
    translate([-windowHeight/2+pinDiameter/2,0,0]) circle(d=pinDiameter);
    square([windowHeight-pinDiameter,pinDiameter],center=true);
    translate([windowHeight/2-pinDiameter/2,0,0]) circle(d=pinDiameter);
}
}
module windowOpeningMesh(){
translate([bandRadius+(watchWearHand-1)*endDiameter/2,0,bandWidth-windowOffset-windowHeight/2])
    rotate(-90,[0,1,0])
        windowOpeningProfile();
translate([0,-bandRadius+watchWearHand*endDiameter/2,bandWidth-windowOffset-windowHeight/2])
    rotate(90,[0,0,1])
    rotate(90,[0,1,0])
        windowOpeningProfile();
}

module pinHoleMesh(){
    translate([bandRadius-endDiameter/2,0,0])
        cylinder(h=bandWidth,d=pinDiameter);
    translate([0,-bandRadius+endDiameter/2,0])
        cylinder(bandWidth,d=pinDiameter);
}

module trimMesh(){
    rotate_extrude(angle = 360,$fn=resolutionStrap)
        translate([bandRadius,0,0]) polygon( trimPts );
}

difference(){
    bandMesh();
    windowOpeningMesh();
    pinHoleMesh();
    trimMesh();
}

```


[User]
I'd like to create a parametric wedge for holding a glass at an angle, specifically to get a nice angled ice cube. The design should be customizable for different glass sizes and angles.

Here's the basic idea:

*   **Glass parameters:** I need to specify the diameter and height of the glass the wedge will hold.
*   **Angle:** The angle at which the glass sits in the wedge needs to be adjustable (like 45 degrees, but I want to change it).
*   **Wedge dimensions:** The width and length of the wedge itself should be adjustable via percentages of the glass diameter and height, respectively.
*   **Inner Cutout:** The wedge will have an inner cutout to hold the glass, and I need to be able to set the width of the material used for the wedge and therefore the gap between the glass and outside of the wedge.
*   **Preview/Render switch:** It should be possible to specify preview vs render settings.

I want the final model to consist of a solid base with an angled top surface that supports the glass at the specified angle. The inner cutout should fit the glass, and there should be an inner cutout for removing excess material for printing.

I'd like to use OpenSCAD and no particular libraries are necessary. I'm expecting the resulting file to be self-contained.

[Assistant]
tumbler-wedge.scad:
```
// -*- mode: SCAD ; c-file-style: "ellemtel" ; coding: utf-8 -*-
//
// A wedge to keep a glass angled.
//
// This is a re-imagining of Thing 2784800, matt sauter's "Whiskey Wedge -
// Angled Ice". (https://www.thingiverse.com/thing:2784800) This is not
// based on that thing, but a new thing to achieve the same effect.
//
// Copyright 2018 Roland Sieker <ospalh@gmail.com>
// Licence: CC-BY-SA 4.0

// How wide the glass to put on this is
glass_diameter = 70; // [30:1:100]

// ... and how tall.
glass_height = 90; // [20:1:200]

// Angle at which the glass rests
angle = 45; // [20:1:70]

// Width of the wedge as a percentage of the glass diameter
wedge_width = 70; // [50:1:99]

// Length of the wedge as a percentage of the glass height
wedge_length = 70; // [50:1:99]

// Distance between the outside and the hole in the inside. The width of the wedge.
wedge_cutout_width = 10; // [3:0.5:30]

// Set this to "render" and click on "Create Thing" when done with the setup.
preview = 1; // [0:render, 1:preview]

/* [Hidden] */

// Done with the customizer

// *******************************************************
// Extra parameters. These can be changed reasonably safely.

w = 1.8;  // Wall width. Not used here, i think.
p = 1.2;  // Bottom, top plate height. In this case, distance of the glass from the freezer floor
c = 0.4;  // Clearance

// *******************************************************
// Some shortcuts. These shouldn't be changed

r_ge = glass_diameter/2 + c;
r_w = glass_diameter/2 * wedge_width/100;

tau = 2 * PI;  // pi is still wrong

gh = glass_height*wedge_length/100;

xy_factor = 1/tan(angle);
// To get from a height to a horizontal width inclined correctly
z_factor = tan(angle);  // The other way around
hb = gh*sin(angle);

ms = 0.01;  // Muggeseggele.

// fn for differently sized objects and fs, fa; all for preview or rendering.
pna = 40;
pnb = 15;
pa = 5;
ps = 1;
rna = 180;
rnb = 30;
ra = 1;
rs = 0.1;
function na() = (preview) ? pna : rna;
function nb() = (preview) ? pnb : rnb;
$fs = (preview) ? ps : rs;
$fa = (preview) ? pa : ra;

// *******************************************************
// End setup

// *******************************************************
// Generate the part

glass_wedge();

// *******************************************************
// Code for the part itself

module glass_wedge()
{
   hc = r_ge*sin(angle) + p;
   difference()
   {
      glass_base();
      translate([0,0, hc])
      {
         glass_cutout();
      }
      inner_cutout();
   }
}

module glass_cutout()
{
   rotate([0,angle,0])
   {
      hull()
      {
         cylinder(r=r_ge, h=gh);
         translate([-r_ge-gh,0,0])
         {
            cylinder(r=r_ge, h=2*gh);
         }
      }
   }

}

module glass_base()
{
   linear_extrude(hb)
   {
      2d_glass_base();
   }
}

module 2d_glass_base()
{
   projection()
   {
      rotate([0,angle,0])
      {
         cylinder(r=r_w, h=gh+c);
      }
   }
}

module inner_cutout()
{
   translate([0,0,-ms])
   {
      linear_extrude(hb+2*ms)
      {
         2d_inner_cutout();
      }
   }
}

module 2d_inner_cutout()
{
   sy = (r_w-wedge_cutout_width)/r_w;
   lh = cos(angle)*(gh+c);
   lx = sin(angle)*r_w+lh;
   sx = (lx-2*wedge_cutout_width)/lx;

   // I think this is not really correct (or the way i wanted it), but,
   // meh, good enough.
   translate([sx*wedge_cutout_width,0])
   {
      scale([sx,sy])
      {
         2d_glass_base();
      }
   }
}

```


[User]
I'm looking to create a customizable car cup holder for an e-cigarette mod, and I'd like it to be designed in OpenSCAD. I want to be able to easily adjust the dimensions to fit different mods.

The basic design will be a frustum (a cone with the top cut off) with a rectangular cutout through it. This cutout should be a rounded rectangle. I need parameters to control the height of the frustum, the upper and lower radii, the width and length of the rectangular cutout, the height of a base wall on the bottom, and the corner radius of the rounded rectangle.

Could you generate an OpenSCAD file that uses parameters for:

*   `Cone_Height`: The height of the frustum.
*   `Upper_Radius`: The radius of the top circle of the frustum.
*   `Lower_Radius`: The radius of the bottom circle of the frustum.
*   `Ecig_body_Width`: The width of the rectangular cutout.
*   `Ecig_body_Length`: The length of the rectangular cutout.
*   `Bottom_Wall_Height`: The height of the solid wall at the bottom of the holder.
*   `Corner_radius`: The radius of the corners of the rectangular cutout.

The rectangular cutout should be centered in the frustum, and it should be extruded down from the top of the frustum to the bottom of the frustum. Also, could you make sure to use the hull() function and linear_extrude() to make the rounded rectangle.

[Assistant]
ciiga_11.scad:
```

Cone_Height = 50;
Upper_Radius = 37;
Lower_Radius = 34;

Ecig_body_Width= 23;
Ecig_body_Length = 36;
Bottom_Wall_Height = 10;
// - Corner radius (optional)
Corner_radius = 2;

difference  (){

translate([0,0,0]) cylinder( h = Cone_Height, r2 = Upper_Radius , r1 = Lower_Radius , $fn=300);
 roundedRect([Ecig_body_Width, Ecig_body_Length,Cone_Height +2],  Corner_radius, $fn=30);

}

module roundedRect(size, radius)
{
	x = size[0];
	y = size[1];
	z = size[2];

	translate ([0,0,Bottom_Wall_Height ]) linear_extrude(height=z+2)
	hull()
	{

		translate([(-x/2)+(radius), (-y/2)+(radius), 0])
		circle(r=radius);

		translate([(x/2)-(radius), (-y/2)+(radius), 0])
		circle(r=radius);

		translate([(-x/2)+(radius), (y/2)-(radius), 0])
		circle(r=radius);

		translate([(x/2)-(radius), (y/2)-(radius), 0])
		circle(r=radius);

	}
}

```


[User]
I'm looking to design a coffee leveler, also known as a distributor, for espresso. It's meant to sit on top of a portafilter basket and help distribute the coffee grounds evenly before tamping.

Here's what I'm envisioning, and what I'd like to be able to customize:

The leveler will have a base and a top section.

*   **Base:** This part will sit inside the portafilter. I need to specify `baseDiameter` and `baseHeight`. It will have a hollowed interior with a customizable wall thickness `wall`.
*   **Top:** This section sits on top of the portafilter basket's rim. I need to be able to control `topDiameter` and `topHeight`. It also needs to be hollowed out, matching the wall thickness of the base. There's a gradual transition (conical shape) from the base diameter to the top diameter using `d1` and `d2`.
*   **Blades:** The leveling action will be done by several blades that rotate around the center. I want to be able to control:
    *   `bladeThickness`
    *   `bladeCount`
    *   `bladeAngle` (the angle of the blades, relative to the horizontal).
    *   The blades need to extend from inside the inner diameter of the base, slightly beyond the outermost diameter of the base itself. They also need to be tall enough to fully cover the height of the base.
    *   The blades should also be cut such that they don't overlap each other or the walls of the top section. I'm thinking a `difference()` operation, using the outer diameter of the leveler.

I'd like all dimensions to be in millimeters. I'd like to use `$fn` values that result in relatively high-resolution curves. For example, I might use `$fn=150` for cylinders.

Could you generate the OpenSCAD code for this?

[Assistant]
coffeeLeveler.scad:
```
////////////////////////////////////////////////////////////////
// PARAMETERS //////////////////////////////////////////////////

baseDiameter = 53;  // in millimiters
baseHeight = 6;
topDiameter = 65;
topHeight = 20;
wall = 2;
bladeThickness = 1.1;
bladeCount = 6;
bladeAngle = 30;

leveller();

module leveller() {
  difference() {
    cylinder(d = baseDiameter, h = baseHeight, $fn = 150);
    translate([0, 0, -1])  // translation for cleaner look on preview
      cylinder(d = baseDiameter - 2*wall, h = baseHeight + 2, $fn=150); // taller for cleaner look on preview
  }
  translate([0, 0, baseHeight])
  difference() {
    cylinder(d1 = baseDiameter, d2 = topDiameter, h = topHeight, $fn=150);
    translate([0, 0, -1])  // translation for cleaner look on preview
      cylinder(d1 = baseDiameter - 2*wall -0.6, d2 = topDiameter-2*wall, h = topHeight + 2, $fn=150);
  }

  for (a = [0 : bladeCount - 1]) {
    angle = a * 360 / bladeCount;
    //translate(radius * [sin(angle), -cos(angle), 0])
    rotate([0, 0, angle])
      blade();
  }

}

module blade() {
  difference() {
    rotate(bladeAngle, [1, 0, 0])
      translate([0, -wall/2, -baseHeight])
       cube([baseDiameter/2 - bladeThickness/2, bladeThickness, 2*baseHeight]);
    translate([-baseDiameter/2, -baseDiameter/2, -topHeight])
      cube([baseDiameter, baseDiameter, topHeight]);
    // cut out blade top corner if blade angle and base are "high"
    difference() {
      cylinder(d = baseDiameter * 2, h = topHeight);
      cylinder(d = baseDiameter, h = topHeight);
    }
  }
}
```


[User]
Okay, I need an OpenSCAD design for a Raspberry Pi camera mount that can attach to a 3D printer bed, specifically a Prusa MK3 at the moment. It should be parametric, so I can adjust things later.

Here's what I need:

**Overall Structure:** The design should have four main parts: the camera housing, a lid for the housing, a post connecting the housing to an arm, and the arm that mounts to the printer bed.

**Camera Housing:**
*   It needs to fit the standard Raspberry Pi camera (v1 or v2). The dimensions are roughly 26x25x1 mm for the PCB, with additional room for the camera module itself. There should also be a small gap for the cable.
*   I need to be able to choose if the camera cable comes out the top or bottom of the case.
*   The lid should be optional to screw on. If it's screwed on, it should use M3 screws.
*   The housing needs a space inside for the camera board, and pins to hold it in place

**Lid:**
*   Should match the camera housing and either fit snugly or be screwable, as set by parameter.
*   Has to have a small inner ridge and pins to hold the PCB down
*   Should close up the cable outlet (except for a hole for the cable itself)

**Post:**
*   A simple post with a screw hole at the top (for the camera housing) and a smaller hole at the bottom for mounting to the arm.
*   The height should be adjustable.
*   Also needs to be mountable to the arm with an M3 screw

**Arm:**
*   This arm should attach to a Prusa MK3 bed frame. It should slide over the frame.
*   The arm's length and rotation angle needs to be customizable.
*   There should be a slot to optionally secure it with a zip tie, but it should be tight enough not to need it.
*   The arm needs to attach to the post with an M3 screw.

**General Parameters:**
*   I need to be able to set the wall thickness.
*   I need to be able to specify the diameter of screw holes and screw head sinking holes.
*   I need to be able to specify the diameter of tap holes in the post.
*   I'd like to be able to control the smoothness of rounded edges using `$fn`.

I think that's it, I'm not trying to use any libraries, but I'll want to be able to use parameters for all of these options.

[Assistant]
combined.scad:
```
/* START main.scad*/
/* START customizer.scad*/
/* [General] */

// Which part do you want to access?
cnf_part = "all"; // [camera:Camera Body, lid:Camera Lid, post:Camera Post, arm:Bed Mounting Arm, all:All]

/* [Camera Case] */

// Do want to screw the lid on the camera body?
cnf_lidscrew = 1; // [0: no, 1: yes]

// Do you want to flip the camera and have the cable at the bottom?
cnf_flip = 0; // [0: no, 1: yes]

/* [Bed Mounting Arm] */

// Which type of arm do you need? Currently only one available
cnf_armtype = "mk3"; // [mk3:Prusa MK3]

// Length of the arm from the mount (mm)
cnf_armlength = 80;

// Rotation of the arm (deg)
cnf_armrotation = 0; // [-45:45]

/* [Camera Post] */

// height of the camera post (mm)
cnf_postheight = 26;

/* [Advanced] */

// smothness of rounded edges
$fn = 70;

// Thickness of Walls (mm)
cnf_walls = 2;

// size of screw holes (mm)
cnf_screw = 4;

// size of screw heads (for sinking them) (mm)
cnf_screwhead = 6;

// size of tap holes (mm)
cnf_drill = 3;

/* [Hidden] */
/* END customizer.scad*/
/* START picamera.scad*/
/* START primitives.scad*/
/**
 * A centered cube, but flat on the Z-Surface
 */
module ccube(v) {
    translate([0, 0, v.z/2]) cube(v, true);
}

/**
 * An upright standing centered cylinder, flat on the Z-Surface
 */
module ccylinder_y(h, d) {
    translate([h/-2, 0, d/2])
        rotate([0, 90, 0])
            cylinder(h=h, d=d);
}

/**
 * Creates a rounded cube
 *
 * @param {vector} v The size of the cube
 * @param {number} r The radius of the rounding
 * @param {bool} flatcenter centered but flat on Z
 */
module roundedCube(v, r=1, flatcenter=true) {
    mv = flatcenter ? [0,0,0] : [v.x/2, v.y/2 ,0];

    translate(mv) hull() {
        // right back bottom
        translate([v.x/2 - r, v.y/2 - r, r])
            sphere(r=r);

        // right front bottom
        translate([v.x/2 - r, v.y/-2 + r, r])
            sphere(r=r);

        // left back bottom
        translate([v.x/-2 + r, v.y/2 - r, r])
            sphere(r=r);

        // left front bottom
        translate([v.x/-2 + r, v.y/-2 + r, r])
            sphere(r=r);

        // right back top
        translate([v.x/2 - r, v.y/2 - r, v.z - r])
            sphere(r=r);

        // right front top
        translate([v.x/2 - r, v.y/-2 + r, v.z - r])
            sphere(r=r);

        // left back top
        translate([v.x/-2 + r, v.y/2 - r, v.z - r])
            sphere(r=r);

        // left front top
        translate([v.x/-2 + r, v.y/-2 + r, v.z - r])
            sphere(r=r);
    }
}
/* END primitives.scad*/

//picamera(part="camera");
//picamera(part="lid");

/**
 * Creates the body or lid for the camera
 *
 * @param {string} part The part to print, either "camera" or "lid"
 * @param {bool} flip Should the cable come out of the bottom?
 * @param {bool} lidscrew Should the be screwed on?
 * @param {number} walls The wall thickness in mm
 * @param {number} screw The diameter of the screw hole
 * @param {number} screwhead The diameter of the screw head hole
 */
module picamera (
    part = "camera",
    flip = false,
    lidscrew = true,
    walls = 2,
    screw = 4,
    screwhead = 4
) {
    // basic setup
    pcb = [26, 25, 1];
    pcb_part = [17, pcb.y, 1.5];
    cable_z = 1; // above pcb
    pcb_clear = 4;
    tab = 14;
    body_z   = walls+pcb.z+pcb_part.z+pcb_clear;
    holder_z = walls+pcb.z+pcb_part.z+cable_z;
    $fn = $fn ? $fn : 90;

    // print part
    if(part == "camera") {
        camera();
    } else {
        lid();
    }

    /**
     * The lid
     */
    module lid() {
        ridge=1; // thickness of the inner ridge
        cable=1; // space for the cable
        pin_off=0.2;

        // the lid itself
        linear_extrude(height=walls) {
            offset(r=walls) {
                square([pcb.x, pcb.y],true);
            }
        }

        translate([0,0,walls]) {
            // the inner ridge
            difference() {
                linear_extrude(height=ridge) {
                    square([pcb.x, pcb.y],true);
                }

                linear_extrude(height=ridge) {
                    offset(r=walls*-1) {
                        square([pcb.x, pcb.y],true);
                    }
                }
            }
            // the pins holding the pcb down (half a rigde shorter)
            difference(){
                pins(4, pcb_clear-pin_off);
                translate([0,0,pcb_clear-ridge/2]) pins(2, ridge);
            }

            // closes the cable outlet (half a ridge smaller than the outlet)
            translate([0, (pcb.y+walls) /2,0]) {
                ccube([pcb_part.x-ridge/2, walls, pcb_clear-cable_z-cable]);
            }
        }

        // the tab for screwing down the lid
        if(lidscrew) translate([0, -1*pcb.y/2, 0]) {
            tab();
        }
    }

    /**
     * Create the camera case
     */
    module camera() {
        holder_space = 10;
        mod = flip ? 1 : -1;

        body();

        // add two arms
        translate([0, mod*(pcb.y/2 + walls), 0]) {
            translate([(holder_space+walls)/-2, 0 , 0]) {
                holderarm(flip);
            }
            translate([(holder_space+walls)/2, 0 , 0]) {
                holderarm(flip);
            }
        }

        // mechanism to screw the lid on
        if(lidscrew) translate([0, pcb.y/-2, 0]) {
            closer();
        }
    }

    /**
     * Screw mechanism for the lid
     *
     * Basically the same as the closer() but we don't need to cut
     * the cylinder and we have no sink hole for the screw head
     */
    module tab() {
        translate([0,-1*walls,0]) {
            difference() {
                cylinder(h=walls, d=tab);
                translate([0, screwhead/-2, walls/-2]) {
                    cylinder(h=walls*2, d=screw);
                }
            }
        }
    }

    /**
     * Screw mechanism for the case
     *
     * Basically the same as the tab() but with a sunken hole for the
     * screw head.
     */
    module closer() {
        translate([0,-1*walls,0]) {
            difference() {
                cylinder(h=body_z, d=tab);

                // drill holes for head and screw
                translate([0, screwhead/-2, 0]) {
                    cylinder(h=body_z/2, d=screwhead);
                    cylinder(h=body_z*2, d=screw);
                }

                // cut off a little less than half
                translate([0, tab/2 + walls, body_z/-2]) {
                    ccube([tab, tab, body_z*2]);
                };
            }
        }
    }

    /**
     * Creates a single holder arm
     */
    module holderarm() {
        length = 10;

        rot = flip ? 180 : 0;

        rotate([0,0,rot]) {
            translate([0,length/-2,0]) {
                difference() {
                    // tapered shape for when the cable is at the same end
                    hull() {
                        ccube([walls, length, holder_z]);
                        translate([0, -1*length, 0]) {
                            ccylinder_y(walls, body_z);
                        }
                    }

                    // the screw hole
                    translate([0, -1*length, body_z/2-screw/2]) {
                        ccylinder_y(walls*2, screw);
                    }
                }
            }
        }
    }

    /**
     * Creates the camera body
     */
    module body() {
        difference() {
            linear_extrude(height=body_z) {
                offset(r=walls) {
                    square([pcb.x, pcb.y],true);
                }
            }
            pcb_cutout();
        }
    }

    /**
     * the 4 pins to hold the pcb
     */
    module pins(d, h) {
        pin_off_w = 2.5; // center from walls
        pin_off_y = 13; // distance upper from lower pin center

        // lower right
        translate([(pcb.x/-2)+pin_off_w, (pcb.y/-2)+pin_off_w, 0]) {
            cylinder(h=h, d=d);
        }

        // lower left
        translate([(pcb.x/2)-pin_off_w, (pcb.y/-2)+pin_off_w, 0]) {
            cylinder(h=h, d=d);
        }

        // upper right
        translate([(pcb.x/-2)+pin_off_w, (pcb.y/-2)+pin_off_w+pin_off_y, 0]) {
            cylinder(h=h, d=d);
        }

        // upper left
        translate([(pcb.x/2)-pin_off_w, (pcb.y/-2)+pin_off_w+pin_off_y, 0]) {
            cylinder(h=h, d=d);
        }
    }

    /**
     * Carves the space for the PCB
     */
    module pcb_cutout() {
        lens = [9, 9, walls];
        lens_yoffset = 2.5; // from center
        pin_d = 1.5;
        cut = lens.z + pcb_part.z + pcb.z; // cut through all

        difference() {
            union() {
                translate([0, lens_yoffset, -1]) {
                    ccube([lens.x, lens.y, lens.z+1], true); // lens
                }
                translate([0,0,lens.z]) {
                    ccube([pcb_part.x, pcb_part.y, pcb_part.z], true); // front parts

                    translate([0,0,pcb_part.z]) {
                        ccube([pcb.x, pcb.y, pcb.z]); // pcb

                        // cable outlet
                        translate([0, pcb_part.y/2, pcb.z+cable_z]) {
                            ccube([pcb_part.x, walls*2, pcb_clear-cable_z]);
                        }
                    }
                }
            }

            pins(pin_d, cut);
        }

        // upper clearance
        translate([0, 0, cut]) {
            ccube([pcb.x, pcb.y, pcb_clear]);
        }
    }
}
/* END picamera.scad*/
/* START post.scad*/

//post();

/**
 * Creates the post to mount the camera on the arm
 *
 * @param {number} height The height of the post in mm
 * @param {number} width The diameter of the post in mm
 * @param {number} screw The diameter of the screw hole
 * @param {number} walls The wall thickness in mm
 * @param {number} drill The diameter of the hole in the post bottom
 */
module post(
    height = 26,
    width = 10,
    screw = 4,
    walls = 2,
    drill = 3,
) {
    holder_space = 10;
    $fn = $fn ? $fn : 90;

    difference() {
        // smooth from round to square
        hull(){
            translate([0,0,(height/3)*2]) {
                roundedCube([width, width, height/3]);
            }
            cylinder(d=width, h=height/3);
        }

        // screw hole
        translate([0, 0, height - screw/2 - walls]) {
            rotate([90,0,0]) {
                cylinder(d=screw, h=width, center=true);
            }
        }

        // drill hole
        cylinder(d=drill, h=(width/3)*2);
    }
}
/* END post.scad*/
/* START arm.scad*/

//arm();

/**
 * Creates the arm for mounting the camera to the bed
 *
 * Currently only the prusa MK3 bed is supported, but others could be
 * added here.
 *
 * @param {number} armlen The length of the arm from the mounting in mm
 * @param {number} armrot The arm's rotation in degrees
 * @param {number} walls The wall thickness in mm
 * @param {number} screw The diameter of the screw hole
 * @param {number} screwhead The diameter of the screw head hole
 */
module arm (
    armlen = 80,
    armrot = 0,
    walls  = 2,
    screw = 4,
    screwhead = 6
) {
    // basic setup
    arm = [armlen, 10, 10];
    bedarm = [17, 12.5, 6.5];
    zip = [4, bedarm.y+walls*2, 0.5]; // zip tie grove
    attachment = bedarm.y+walls*2; // the size of the attachment overlap
    $fn = $fn ? $fn : 90;

    // build part
    prusaMK3mount();
    arm();

    /**
     * Creates the actual Arm
     *
     * This is basically device independent. The arm is postioned
     * to be attached (and rotated) around [0,0]
     */
    module arm() {
        rotate([0, 0, armrot]) {
            translate([attachment/-4, arm.y/-2, 0]) {
                difference(){
                    roundedCube(arm, walls, false);
                    translate([arm.x-screwhead/2-walls, arm.y/2, 0]) {
                        cylinder(h=arm.z, d=screw);
                        translate([0,0,arm.z/2])
                          cylinder(h=arm.z/2, d=screwhead);
                    }
                }
            }
        }
    }

    /**
     * Create the mounting mechanism for a Prusa i3 MK3
     *
     * The attachment point for the arm is at [0,0]
     */
    module prusaMK3mount() {
        open = [bedarm.x - 2.5, 7, walls];

        // move everything so that the attachment point is centered
        translate([
            (bedarm.x+walls+attachment/2)*-1,
            (bedarm.y+walls*2)/-2,
            0
        ]) {
            // create the casing
            difference(){
                roundedCube([
                    bedarm.x+walls+attachment,
                    bedarm.y+walls*2,
                    bedarm.z+walls*2
                ], walls, false);

                translate([0, walls, walls]) {
                    // hole for the arm
                    cube(bedarm);

                    // opening for the screw
                    translate([0, bedarm.y/2 - open.y/2, -walls]) {
                        cube(open);
                    }
                }

                // zip tie grove
                translate([zip.x, 0, 0]){
                    cube(zip);
                }
            }
        }
    }
}
/* END arm.scad*/

print_part(cnf_part);

/**
 * Decide which part to print based on the given parameter
 */
module print_part(part="all") {
    if (part == "camera" ) {
        picamera(
            part="camera",
            flip = cnf_flip,
            lidscrew = cnf_lidscrew,
            walls = cnf_walls,
            screw = cnf_screw,
            screwhead = cnf_screwhead
        );
    } else if (part == "lid") {
        picamera(
              part="lid",
              flip = cnf_flip,
              lidscrew = cnf_lidscrew,
              walls = cnf_walls,
              screw = cnf_screw,
              screwhead = cnf_screwhead
          );
    } else if (part == "post") {
        post(
          height = cnf_postheight,
          screw = cnf_screw,
          walls = cnf_walls,
          drill = cnf_drill
        );
    } else if (part == "arm") {
        arm (
            armlen = cnf_armlength,
            armrot = cnf_armrotation,
            walls  = cnf_walls,
            screw = cnf_screw,
            screwhead = cnf_screwhead
        );
    } else {
        translate([-30, 0, 0]) print_part("camera");
        translate([30, 0, 0]) print_part("lid");
        translate([0, -45, 0]) print_part("post");
        translate([0, 45, 0]) print_part("arm");
    }
}
/* END main.scad*/

```


[User]
I'm looking to create a customizable 3D model that looks like an impossible torus or a Möbius strip, but instead of a rectangular cross-section, I want to use different shapes. I'd like to be able to choose between a square, a hexagon, a star, and a triangle for the cross-sectional shape.

I need the following parameters to be customizable:

*   **shape:** A dropdown menu to select the cross-sectional shape (square, hexagon, star, triangle).
*   **m_radius:** The radius of the ring itself.
*   **twist_angle:** The twist applied to the ring. It should accept a numerical value. Please note, the twist angle needs to be a multiple of 120 for the triangle, a multiple of 90 for the square, or a multiple of 60 for the hexagon and star for it to appear to wrap properly.
*   **scale_factor:** A scale factor that affects the size of the cross-sectional shape.
*  **quality:** Control for the quality using the $fn variable.

I'm aware that there are libraries out there that could be useful for this. I've found a user on github, JustinSDK, who has made a dotSCAD library that seems perfect for this. It has the necessary `ring_extrude.scad`, `cross_sections.scad`, and `polysections.scad` files to create something like this, and I'd like you to generate the design using those. There are also some dependency functions contained within the library, but I believe these can be addressed by simply bundling the necessary code.

Could you generate the OpenSCAD files that I need for this?

[Assistant]
BUNDLED_impossible_torus.scad:
```

shape = "square"; // [triangle,square,hexagon,star]
//radius of the ring itself
m_radius = 25; // [0:200]
//twist angle, needs to be a multiple of 120 for triangle, 90 for square, or a multiple of 60 for hexagon and stars
twist_angle = 180; // [0:30:1080]
//scale factor of the 2D shape (square/hexagon/star)
scale_factor = 0.66;// [0.1:0.1:2]

//part quality AKA $fn
quality = 300; //[20:500]

$fn = quality;
/* [Hidden] */
qsf = 1;
square_pts = [
    [-10/qsf*scale_factor,-10/qsf*scale_factor],
    [-10/qsf*scale_factor,10/qsf*scale_factor],
    [10/qsf*scale_factor,10/qsf*scale_factor],
    [10/qsf*scale_factor,-10/qsf*scale_factor]
];

hsf = 43.3;
hex_pts = [
    [250/hsf*scale_factor,-433.3333/hsf*scale_factor],
    [-250/hsf*scale_factor,-433.3333/hsf*scale_factor],
    [-500/hsf*scale_factor,0/hsf*scale_factor],
    [-250/hsf*scale_factor,433.3333/hsf*scale_factor],
    [250/hsf*scale_factor,433.3333/hsf*scale_factor],
    [500/hsf*scale_factor,0/hsf*scale_factor]
];

ssf = 5;
star_pts = [
    [49.999999/ssf*scale_factor,28.86754/ssf*scale_factor],
    [14.433754/ssf*scale_factor,25.00002/ssf*scale_factor],
    [-1E-06/ssf*scale_factor,57.73505/ssf*scale_factor],
    [-14.433757/ssf*scale_factor,25.00002/ssf*scale_factor],
    [-49.99999877/ssf*scale_factor,28.86754/ssf*scale_factor],
    [-28.86751/ssf*scale_factor,3E-05/ssf*scale_factor],
    [-49.99999851/ssf*scale_factor,-28.86749/ssf*scale_factor],
    [-14.433754/ssf*scale_factor,-24.99998/ssf*scale_factor],
    [1E-06/ssf*scale_factor,-57.735/ssf*scale_factor],
    [14.433757/ssf*scale_factor,-24.99998/ssf*scale_factor],
    [49.999999/ssf*scale_factor,-28.86749/ssf*scale_factor],
    [28.86751/ssf*scale_factor,3E-05/ssf*scale_factor]
];

tsf = 100;
tri_pts = [
    [0/tsf*scale_factor,-1000/tsf*scale_factor],
    [-866.67/tsf*scale_factor,500/tsf*scale_factor],
    [866.67/tsf*scale_factor,500/tsf*scale_factor],
];

if (shape == "square") {
    ring_extrude(square_pts, radius = m_radius, twist = twist_angle);
} else if (shape == "hexagon") {
    ring_extrude(hex_pts, radius = m_radius, twist = twist_angle);
} else if (shape == "star") {
    ring_extrude(star_pts, radius = m_radius, twist = twist_angle);
} else if (shape == "triangle") {
    ring_extrude(tri_pts, radius = m_radius, twist = twist_angle);
}

//FOLLOWING CODE IS BUNDLED IN FOR CUSTOMIZER along with license statements
//include <rotate_p.scad>;
//include <cross_sections.scad>;
//include <polysections.scad>;
//include <ring_extrude.scad>;
//also added dependency functions
/**
* rotate_p.scad
*
* Rotates a point 'a' degrees around an arbitrary axis.
* The rotation is applied in the following order: x, y, z.
*
* @copyright Justin Lin, 2017
* @license https://opensource.org/licenses/lgpl-3.0.html
*
* @see https://openhome.cc/eGossip/OpenSCAD/lib-rotate_p.html
*
**/

//include <__private__/__to2d.scad>;
//include <__private__/__to3d.scad>;

function _rotx(pt, a) =
    let(cosa = cos(a), sina = sin(a))
    [
        pt[0],
        pt[1] * cosa - pt[2] * sina,
        pt[1] * sina + pt[2] * cosa
    ];

function _roty(pt, a) =
    let(cosa = cos(a), sina = sin(a))
    [
        pt[0] * cosa + pt[2] * sina,
        pt[1],
        -pt[0] * sina + pt[2] * cosa,
    ];

function _rotz(pt, a) =
    let(cosa = cos(a), sina = sin(a))
    [
        pt[0] * cosa - pt[1] * sina,
        pt[0] * sina + pt[1] * cosa,
        pt[2]
    ];

function _rotate_p_3d(point, a) =
    _rotz(_roty(_rotx(point, a[0]), a[1]), a[2]);

function to_avect(a) =
     len(a) == 3 ? a : (
         len(a) == 2 ? [a[0], a[1], 0] : (
             len(a) == 1 ? [a[0], 0, 0] : [0, 0, a]
         )
     );

function rotate_p(point, a) =
    let(angle = to_avect(a))
    len(point) == 3 ?
        _rotate_p_3d(point, angle) :
        __to2d(
            _rotate_p_3d(__to3d(point), angle)
        );

/**
* ring_extrude.scad
*
* Rotational extrusion spins a 2D shape around the Z-axis.
* It's similar to the built-in `rotate_extrude`; however, it supports angle, twist and scale options.
*
* @copyright Justin Lin, 2017
* @license https://opensource.org/licenses/lgpl-3.0.html
*
* @see https://openhome.cc/eGossip/OpenSCAD/lib-ring_extrude.html
*
**/

//include <__private__/__frags.scad>;
//include <__private__/__ra_to_xy.scad>;

module ring_extrude(shape_pts, radius, angle = 360, twist = 0, scale = 1.0, triangles = "SOLID") {
    if(angle == 360 && twist == 0 && scale == 1.0) {
        rotate_extrude()
            translate([radius, 0, 0])
                polygon(shape_pts);
    } else {
        a_step = 360 / __frags(radius);

        angles = __is_vector(angle) ? angle : [0, angle];

        m = floor(angles[0] / a_step) + 1;
        n = floor(angles[1] / a_step);

        leng = radius * cos(a_step / 2);

        begin_r =
            leng / cos((m - 0.5) * a_step - angles[0]);

        end_r =
            leng / cos((n + 0.5) * a_step - angles[1]);

        angs = concat(
            [[90, 0, angles[0]]],
            m > n ? [] : [for(i = [m:n]) [90, 0, a_step * i]]
        );
        pts = concat(
            [__ra_to_xy(begin_r, angles[0])],
            m > n ? [] : [for(i = [m:n]) __ra_to_xy(radius, a_step * i)]
        );

        is_angle_frag_end = angs[len(angs) - 1][2] == angles[1];

        all_angles = is_angle_frag_end ?
            angs :
            concat(angs, [[90, 0, angles[1]]]);

        all_points = is_angle_frag_end ?
            pts :
            concat(pts, [__ra_to_xy(end_r, angles[1])]);

        sections = cross_sections(shape_pts, all_points, all_angles, twist, scale);

        polysections(
            sections,
            triangles = triangles
        );

        // hook for testing
        test_ring_extrude(sections);
    }
}

// Override it to test
module test_ring_extrude(sections) {

}
/**
* polysections.scad
*
* Crosscutting a tube-like shape at different points gets several cross-sections.
* This module can operate reversely. It uses cross-sections to construct a tube-like shape.
*
* @copyright Justin Lin, 2017
* @license https://opensource.org/licenses/lgpl-3.0.html
*
* @see https://openhome.cc/eGossip/OpenSCAD/lib-polysections.html
*
**/

include <__private__/__reverse.scad>;

module polysections(sections, triangles = "SOLID") {

    function side_indexes(sects, begin_idx = 0) =
        let(
            leng_sects = len(sects),
            leng_pts_sect = len(sects[0])
        )
        concat(
            [
                for(j = [begin_idx:leng_pts_sect:begin_idx + (leng_sects - 2) * leng_pts_sect])
                    for(i = [0:leng_pts_sect - 1])
                        [
                            j + i,
                            j + (i + 1) % leng_pts_sect,
                            j + (i + 1) % leng_pts_sect + leng_pts_sect
                        ]
            ],
            [
                for(j = [begin_idx:leng_pts_sect:begin_idx + (leng_sects - 2) * leng_pts_sect])
                    for(i = [0:leng_pts_sect - 1])
                        [
                            j + i,
                            j + (i + 1) % leng_pts_sect + leng_pts_sect ,
                            j + i + leng_pts_sect
                        ]
            ]
        );

    function search_at(f_sect, p, leng_pts_sect, i = 0) =
        i < leng_pts_sect ?
            (p == f_sect[i] ? i : search_at(f_sect, p, leng_pts_sect, i + 1)) : -1;

    function the_same_after_twisting(f_sect, l_sect, leng_pts_sect) =
        let(
            found_at_i = search_at(f_sect, l_sect[0], leng_pts_sect)
        )
        found_at_i <= 0 ? false :
            l_sect == concat(
                [for(i = [found_at_i:leng_pts_sect-1]) f_sect[i]],
                [for(i = [0:found_at_i - 1]) f_sect[i]]
            );

    function to_v_pts(sects) =
            [
            for(sect = sects)
                for(pt = sect)
                    pt
            ];

    module solid_sections(sects) {

        leng_sects = len(sects);
        leng_pts_sect = len(sects[0]);
        first_sect = sects[0];
        last_sect = sects[leng_sects - 1];

        v_pts = [
            for(sect = sects)
                for(pt = sect)
                    pt
        ];

        function begin_end_the_same() =
            first_sect == last_sect ||
            the_same_after_twisting(first_sect, last_sect, leng_pts_sect);

        if(begin_end_the_same()) {
            f_idxes = side_indexes(sects);

            polyhedron(
                v_pts,
                f_idxes
            );

            // hook for testing
            test_polysections_solid(v_pts, f_idxes);
        } else {
            first_idxes = [for(i = [0:leng_pts_sect - 1]) leng_pts_sect - 1 - i];
            last_idxes = [
                for(i = [0:leng_pts_sect - 1])
                    i + leng_pts_sect * (leng_sects - 1)
            ];

            f_idxes = concat([first_idxes], side_indexes(sects), [last_idxes]);

            polyhedron(
                v_pts,
                f_idxes
            );

            // hook for testing
            test_polysections_solid(v_pts, f_idxes);
        }
    }

    module hollow_sections(sects) {
        leng_sects = len(sects);
        leng_sect = len(sects[0]);
        half_leng_sect = leng_sect / 2;
        half_leng_v_pts = leng_sects * half_leng_sect;

        function strip_sects(begin_idx, end_idx) =
            [
                for(i = [0:leng_sects - 1])
                    [
                        for(j = [begin_idx:end_idx])
                            sects[i][j]
                    ]
            ];

        function first_idxes() =
            [
                for(i =  [0:half_leng_sect - 1])
                    [
                       i,
                       i + half_leng_v_pts,
                       (i + 1) % half_leng_sect + half_leng_v_pts,
                       (i + 1) % half_leng_sect
                    ]
            ];

        function last_idxes(begin_idx) =
            [
                for(i =  [0:half_leng_sect - 1])
                    [
                       begin_idx + i,
                       begin_idx + (i + 1) % half_leng_sect,
                       begin_idx + (i + 1) % half_leng_sect + half_leng_v_pts,
                       begin_idx + i + half_leng_v_pts
                    ]
            ];

        outer_sects = strip_sects(0, half_leng_sect - 1);
        inner_sects = strip_sects(half_leng_sect, leng_sect - 1);

        outer_v_pts =  to_v_pts(outer_sects);
        inner_v_pts = to_v_pts(inner_sects);

        outer_idxes = side_indexes(outer_sects);
        inner_idxes = [
            for(idxes = side_indexes(inner_sects, half_leng_v_pts))
                __reverse(idxes)
        ];

        first_outer_sect = outer_sects[0];
        last_outer_sect = outer_sects[leng_sects - 1];
        first_inner_sect = inner_sects[0];
        last_inner_sect = inner_sects[leng_sects - 1];

        leng_pts_sect = len(first_outer_sect);

        function begin_end_the_same() =
           (first_outer_sect == last_outer_sect && first_inner_sect == last_inner_sect) ||
           (
               the_same_after_twisting(first_outer_sect, last_outer_sect, leng_pts_sect) &&
               the_same_after_twisting(first_inner_sect, last_inner_sect, leng_pts_sect)
           );

        v_pts = concat(outer_v_pts, inner_v_pts);

        if(begin_end_the_same()) {
            f_idxes = concat(outer_idxes, inner_idxes);

            polyhedron(
                v_pts,
                f_idxes
            );

            // hook for testing
            test_polysections_solid(v_pts, f_idxes);
        } else {
            first_idxes = first_idxes();
            last_idxes = last_idxes(half_leng_v_pts - half_leng_sect);

            f_idxes = concat(first_idxes, outer_idxes, inner_idxes, last_idxes);

            polyhedron(
                v_pts,
                f_idxes
            );

            // hook for testing
            test_polysections_solid(v_pts, f_idxes);
        }
    }

    module triangles_defined_sections() {
        module tri_sections(tri1, tri2) {
            hull() polyhedron(
                points = concat(tri1, tri2),
                faces = [
                    [0, 1, 2],
                    [3, 5, 4],
                    [1, 3, 4], [2, 1, 4], [2, 3, 0],
                    [0, 3, 1], [2, 4, 5], [2, 5, 3]
                ]
            );
        }

        module two_sections(section1, section2) {
            for(idx = triangles) {
               tri_sections(
                    [
                        section1[idx[0]],
                        section1[idx[1]],
                        section1[idx[2]]
                    ],
                    [
                        section2[idx[0]],
                        section2[idx[1]],
                        section2[idx[2]]
                    ]
                );
            }
        }

        for(i = [0:len(sections) - 2]) {
             two_sections(
                 sections[i],
                 sections[i + 1]
             );
        }
    }

    if(triangles == "SOLID") {
        solid_sections(sections);
    } else if(triangles == "HOLLOW") {
        hollow_sections(sections);
    }
    else {
        triangles_defined_sections();
    }
}

// override it to test

module test_polysections_solid(points, faces) {

}

/**
* cross_sections.scad
*
* Given a 2D shape, points and angles along the path, this function
* will return all cross-sections.
*
* @copyright Justin Lin, 2017
* @license https://opensource.org/licenses/lgpl-3.0.html
*
* @see https://openhome.cc/eGossip/OpenSCAD/lib-cross_sections.html
*
**/

//include <__private__/__to3d.scad>;
//include <__private__/__is_vector.scad>;

function cross_sections(shape_pts, path_pts, angles, twist = 0, scale = 1.0) =
    let(
        len_path_pts_minus_one = len(path_pts) - 1,
        sh_pts = len(shape_pts[0]) == 3 ? shape_pts : [for(p = shape_pts) __to3d(p)],
        pth_pts = len(path_pts[0]) == 3 ? path_pts : [for(p = path_pts) __to3d(p)],
        scale_step_vt = __is_vector(scale) ?
            [(scale[0] - 1) / len_path_pts_minus_one, (scale[1] - 1) / len_path_pts_minus_one] :
            [(scale - 1) / len_path_pts_minus_one, (scale - 1) / len_path_pts_minus_one],
        scale_step_x = scale_step_vt[0],
        scale_step_y = scale_step_vt[1],
        twist_step = twist / len_path_pts_minus_one
    )
    [
        for(i = [0:len_path_pts_minus_one])
            [
                for(p = sh_pts)
                let(scaled_p = [p[0] * (1 + scale_step_x * i), p[1] * (1 + scale_step_y * i), p[2]])
                    rotate_p(
                        rotate_p(scaled_p, twist_step * i)
                        , angles[i]
                    ) + pth_pts[i]
            ]
    ];

function __to3d(p) = [p[0], p[1], 0];
function __to2d(p) = [p[0], p[1]];
function __ra_to_xy(r, a) = [r * cos(a), r * sin(a)];
function __frags(radius) = $fn > 0 ?
            ($fn >= 3 ? $fn : 3) :
            max(min(360 / $fa, radius * 6.28318 / $fs), 5);
function __reverse(vt) =
    let(leng = len(vt))
    [
        for(i = [0:leng - 1])
            vt[leng - 1 - i]
    ];
function __is_vector(value) = !(value >= "") && len(value) != undef;
```


[User]
Hi, I'm looking to create a set of parts for a toy based on the Kiddicraft Twist and Turn system. I've seen some attempts, but I really need a fully parametric design that I can adjust to fit my needs.

Specifically, I need to generate:

1.  **Threaded Rod:** This is the core of the system.
    *   It needs a customizable threaded length. Let's call this `thread_length`. The original was around 148.77mm, but I want to be able to change that.
    *   The outer diameter of the thread should also be adjustable (e.g., `thread_outer_diameter`). The original was intended to match loosely with 23.5mm nuts, but I have a preference for 22mm.
    *   The thread step or pitch (the distance between threads) needs to be parametric too; this was originally 4.24mm (e.g., `thread_step`).
    *   The thread's profile is also important, the angle (in degrees) the step makes should be editable, call this `step_shape_degrees`.  52 degrees seems correct based on prior attempts.
    *   I'll also need to be able to set the resolution of the thread, probably as an increment (e.g., `resolution`).  2 is a good starting point, and is fine for the final STL files.
    *   At each end of the rod, the non-threaded part of the rod should be rounded, so that it looks like a double-ended rod - think of a dog bone shape, but made up of cylinders. The non-threaded length (`non_thread_length`) should also be customizable, the original is 7.77mm.
    *   I'll also need an option to customize the diameter of this non-threaded section; call this `non_thread_diameter`. -1 means same as inner diameter, 0 means same as outer diameter, a given value is the exact diameter.
    *   Both ends of the rod should have an optional countersink of variable size.
    *   Importantly, this needs to be a double ended rod - no traditional screw head.

2.  **Nuts:** These thread onto the rod.
    *   I need two types: a regular hex nut and a "wing nut."
        *   For both types, I'll need to set the outer diameter of the nut (`nut_diameter`).
        *  The height of the nut should be parametric (`nut_height`).
        *   They need to have matching threads; so the outer diameter of the thread on the nut needs to be configurable (`nut_thread_outer_diameter`), as does the thread step (`nut_thread_step`).
        *   The thread profile angle needs to be editable for the nut as well (`nut_step_shape_degrees`).
        *   I want to set the resolution on the nuts separately from the rod (`nut_resolution`).
        *   For the regular hex nut, I'll need to set the number of facets, which defaults to 6 (`facets`).
        *   For the wing nut, I need a `wing_ratio` to define the size of the wing portions based on the nut height, and it defaults to 1.

3. **Washers:** Simple flat washers for the system.
    *   I need to specify the outer diameter of the washer (`outer_diameter`) and inner diameter (`inner_diameter`), and a thickness (`thickness`).

I don't think you'll need any special libraries for the shapes.  I've seen some using `polyScrewThread.scad` or something similar for the threads.

Can you generate the OpenSCAD code for this?

[Assistant]
Twist_And_Turn_-_threaded_rod.scad:
```
// Kiddicraft Twist And Turn threaded rod generator
//
// https://www.thingiverse.com/thing:3182600
//
// by Erick Neilson - 247generator @ thingiverse - 2018
//
// based on the 'Nut Job', hacked for double ended non-threaded curved rod ends
// and customizer options optimized for the relevant settings only.
//
//
//
/* 'Nut Job' nut, bolt, washer and threaded rod factory by Mike Thompson 1/12/2013, Thingiverse: mike_linus
 *
 * Licensing: This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Australia License.
 * Further information is available here - http://creativecommons.org/licenses/by-nc-sa/3.0/au/deed.en_GB
 *
 * v2 8/12/2013 - added socket head types
 * v3 2/11/2014 - adjusted wing nut algorithm for better behaviour with unusual nut sizes and added ISO262 metric references
 * v4 31/12/2014 - added optional texture to socket heads, added ability to change the number of facets for a hex head
 * and adjusted wingnut base level on certain nut sizes
 * v5 11/1/2015 - added phillips and slot drive types and improved texture handling
 * v6 21/2/2015 - added wing ratio to wingnuts
 * v7 6/3/2016 - added extended options to control number of facets on nuts, square sockets (or any number of facets) and socket depth control
 * v8 1/1/2017 - modified library code to remove dependence on deprecated 'assign' statement
 *
 * This script generates nuts, bolts, washers and threaded rod using the library
 * script: polyScrewThead.scad (modified/updated version polyScrewThread_r1.scad)
 * http://www.thingiverse.com/thing:8796, CC Public Domain
 *
 * Defaults are for a 8mm diameter bolts, rod, matching nuts and wing nuts that work well together
 * without cleanup or modification. Some default parameters such as the nut outer diameter are deliberately
 * altered to produce a snug fit that can still be hand tightened. This may need to be altered
 * depending on individual printer variances, slicing tools, filament etc. Suggest printing a matching
 * bolt and nut and adjusting as necessary.  Note: slow print speeds, low temperatures and solid
 * fill are recommended for best results.
 */

/* [Threaded Rod Options] */

//Length of the threaded section, 148.77mm for original full length rod.
thread_length  					= 148.77;
//Outer diameter of the thread to mesh loosely with 23.5mm nuts
thread_outer_diameter           = 22.0;
//Resolution (lower values for higher resolution slows rendering - 1.0 for the STLs)
resolution    					= 2.0;

/* [Extended Options] */

//Length of the non-threaded section, 7.77mm default.
non_thread_length				= 7.77;
//Thread step or Pitch (4.24mm matches the original product)
thread_step    					= 4.24;
//Step shape degrees (52 degrees is what generates the correct inner thread diameter)
step_shape_degrees 				= 52;

/* [hidden] */

type						    = "rod";//[nut,bolt,rod,washer]
//Head type - Hex, Socket Cap, Button Socket Cap or Countersunk Socket Cap (ignored for Rod)
head_type              			= "hex";//[hex,socket,button,countersunk]
//Drive type - Socket, Phillips, Slot (ignored for Hex head type and Rod)
drive_type              		= "socket";//[socket,phillips,slot]
//Distance between flats for the hex head or diameter for socket or button head (ignored for Rod)
head_diameter    				= 12;
//Height of the head (ignored for Rod)
head_height  					= 5;
//Diameter of drive type (ignored for Hex head and Rod)
drive_diameter					= 5;
//Width of slot aperture for phillips or slot drive types
slot_width					    = 1;
//Depth of slot aperture for slot drive type
slot_depth 					    = 2;
//Surface texture (socket head only)
texture                         = "exclude";//[include,exclude]
//Type: Normal or WingNut
nut_type	                    = "normal";//[normal,wingnut]
//Distance between flats for the hex nut
nut_diameter    				= 12;
//Height of the nut
nut_height	  				    = 6;
//Outer diameter of the bolt thread to match (usually set about 1mm larger than bolt diameter to allow easy fit - adjust to personal preferences)
nut_thread_outer_diameter     	= 9;
//Thread step or Pitch (2mm works well for most applications ref. ISO262: M3=0.5,M4=0.7,M5=0.8,M6=1,M8=1.25,M10=1.5)
nut_thread_step    				= 2;
//Step shape degrees (45 degrees is optimised for most printers ref. ISO262: 30 degrees)
nut_step_shape_degrees 			= 52;
//Wing radius ratio.  The proportional radius of the wing on the wing nut compared to the nut height value (default = 1)
wing_ratio                      = 1;
wing_radius=wing_ratio * nut_height;
//Inner Diameter (suggest making diameter slightly larger than bolt diameter)
inner_diameter					= 8;
//Outer Diameter
outer_diameter					= 14;
//Thickness
thickness					    = 2;
//Number of facets for hex head type or nut. Default is 6 for standard hex head and nut
facets                          = 6;
//Number of facets for hole in socket head. Default is 6 for standard hex socket
socket_facets                   = 6;
//Depth of hole in socket head. Default is 3.5
socket_depth                    = 3.5;
nut_resolution    				= resolution;
//Countersink in both ends
countersink  					= 2;
//Diameter for the non-threaded section (-1: Same as inner diameter of the thread, 0: Same as outer diameter of the thread, value: The given value)
non_thread_diameter				= -1;

//Hex Bolt
if (type=="bolt" && head_type=="hex")
{
	hex_screw(thread_outer_diameter,thread_step,step_shape_degrees,thread_length,resolution,countersink,head_diameter,head_height,non_thread_length,non_thread_diameter);
}

//Rod
if (type=="rod")
{
	hex_screw(thread_outer_diameter,thread_step,step_shape_degrees,thread_length,resolution,countersink,head_diameter,0,non_thread_length,non_thread_diameter);
}

//Hex Nut (normally slightly larger outer diameter to fit on bolt correctly)
if (type=="nut" && nut_type=="normal")
{
	hex_nut(nut_diameter,nut_height,nut_thread_step,nut_step_shape_degrees,nut_thread_outer_diameter,nut_resolution);
}

//Wing Nut variation of hex nut. Cylinders added to each side of nut for easy turning - ideal for quick release applications
if (type=="nut" && nut_type=="wingnut")
{
	rotate([0,0,30])hex_nut(nut_diameter,nut_height,nut_thread_step,nut_step_shape_degrees,nut_thread_outer_diameter,nut_resolution); //nut
	translate([(nut_diameter/2)+wing_radius-1,1.5,wing_radius/2+1])rotate([90,0,0])wing(); //attach wing
	mirror(1,0,0)translate([(nut_diameter/2)+wing_radius-1,1.5,wing_radius/2+1])rotate([90,0,0])wing(); //attach wing
}

module wing()
{
	difference()
	{
		cylinder(r=wing_radius,h=3,$fn=64); //cylinder
		union()
		{
			translate([-wing_radius,-wing_radius-1,-0.5])cube([wing_radius*2,wing_radius/2,wing_radius*2]); //remove overhang so flush with base of nut
			rotate([0,0,90])translate([-wing_radius,wing_radius-1,-0.5])cube([wing_radius*2,wing_radius/2,wing_radius*2]); //remove overhangs so flush with side of nut
		}
	}
}

//Washer
if (type=="washer")
{
	difference()
	{
		cylinder(r=outer_diameter/2,h=thickness,$fn=100);
		translate([0,0,-0.1])cylinder(r=inner_diameter/2,h=thickness+0.2,$fn=100);
	}
}

//Socket Head Bolt
if (type=="bolt" && head_type!="hex")
{
	socket_screw(thread_outer_diameter,thread_step,step_shape_degrees,thread_length,resolution,countersink,head_diameter,head_height,non_thread_length,non_thread_diameter);
}

module phillips_base()
{
	linear_extrude(slot_width)polygon(points=[[0,0],[(drive_diameter-slot_width)/2,9/5*(drive_diameter-slot_width)/2],[(drive_diameter+slot_width)/2,9/5*(drive_diameter-slot_width)/2],[drive_diameter,0]]);
	translate([(drive_diameter-slot_width)/2,0,(drive_diameter+slot_width)/2])rotate([0,90,0])linear_extrude(slot_width)polygon(points=[[0,0],[(drive_diameter-slot_width)/2,9/5*(drive_diameter-slot_width)/2],[(drive_diameter+slot_width)/2,9/5*(drive_diameter-slot_width)/2],[drive_diameter,0]]);
}

module phillips_fillet()
{
	union()
	{
		translate([-(drive_diameter-slot_width)/2-(slot_width/2),slot_width/2,0])rotate([90,0,0])phillips_base();
		translate([0,0,9/5*(drive_diameter-slot_width)/2])union()
		{
			inner_curve();
			rotate([0,0,90])inner_curve();
			rotate([0,0,180])inner_curve();
			rotate([0,0,270])inner_curve();
		}
	}
}

module inner_curve()
{
	translate([slot_width/2,-slot_width/2,0])rotate([0,90,0])linear_fillet(9/5*(drive_diameter-slot_width)/2,drive_diameter/10);
}

//basic 2d profile used for fillet shape
module profile(radius)
{
  difference()
  {
    square(radius);
    circle(r=radius);
  }
}

//linear fillet for use along straight edges
module linear_fillet(length,profile_radius)
{
	translate([0,-profile_radius,profile_radius])rotate([0,90,0])linear_extrude(height=length,convexity=10)profile(profile_radius);
}

module phillips_drive()
{
	intersection()
	{
		phillips_fillet();
		cylinder(9/5*(drive_diameter-slot_width)/2,drive_diameter/2+(slot_width/2),slot_width/2);
	}
}

module socket_screw(od,st,lf0,lt,rs,cs,df,hg,ntl,ntd)
{
    ntr=od/2-(st/2)*cos(lf0)/sin(lf0);
	$fn=60;

	difference()
	{
    		union()
    		{
        		if (head_type=="socket")
				{
					socket_head(hg,df);
				}

        		if (head_type=="button")
				{
					button_head(hg,df);
				}

        		if (head_type=="countersunk")
				{
					countersunk_head(hg,df);
				}

        		translate([0,0,hg])
        		if ( ntl == 0 )
        		{
          		cylinder(h=0.01, r=ntr, center=true);
        		}
        		else
        		{
            		if ( ntd == -1 )
            		{
                		cylinder(h=ntl+0.01, r=ntr, $fn=floor(od*PI/rs), center=false);
            		}
            		else if ( ntd == 0 )
            		{
                		union()
                		{
                    		cylinder(h=ntl-st/2,r=od/2, $fn=floor(od*PI/rs), center=false);
                    		translate([0,0,ntl-st/2])
                    		cylinder(h=st/2,
                             r1=od/2, r2=ntr,
                             $fn=floor(od*PI/rs), center=false);
                		}
            		}
            		else
            		{
                		cylinder(h=ntl, r=ntd/2, $fn=ntd*PI/rs, center=false);
            		}
        		}
        		translate([0,0,ntl+hg]) screw_thread(od,st,lf0,lt,rs,cs);
    		}
		//create opening for specific drive type
		if (drive_type=="socket")
		{
			cylinder(r=drive_diameter/2,h=socket_depth,$fn=socket_facets); //socket
			#translate([0,0,socket_depth])cylinder(r1=drive_diameter/2,r2=0,h=drive_diameter/3,$fn=socket_facets); //socket tapers at base to allow printing without bridging and improve socket grip
		}
		else
		{
			if (drive_type=="phillips")
			{
				translate([0,0,-0.001])phillips_drive();
			}
			else //slot
			{
				translate([-(drive_diameter)/2,slot_width/2,-0.001])rotate([90,0,0])cube([drive_diameter,slot_depth,slot_width]);
			}
		}
	}
}

module socket_head(hg,df)
{
	texture_points=2*PI*(head_diameter/2);
	texture_offset=head_diameter/18;
	texture_radius=head_diameter/24;

	rd0=df/2/sin(60);
	x0=0;	x1=df/2;	x2=x1+hg/2;
	y0=0;	y1=hg/2;	y2=hg;

	intersection()
	{
	   	cylinder(h=hg, r=rd0, $fn=60, center=false);
		rotate_extrude(convexity=10, $fn=6*round(df*PI/6/0.5))
		polygon([ [x0,y0],[x1,y0],[x2,y1],[x1,y2],[x0,y2] ]);
	}

	if (texture=="include") //add texture to socket head. Adjust texture density and size using texture variables above
	{
		for (i= [1:texture_points])
		{
			translate([cos(360/texture_points*i)*(head_diameter/2+texture_offset), sin(360/texture_points*i)*(head_diameter/2+texture_offset), 1 ])
			rotate([0,0,360/texture_points*i])cylinder(r=texture_radius,h=head_height*0.6,$fn=3);
		}
	}

}

module button_head(hg,df)
{
	rd0=df/2/sin(60);
	x0=0;	x1=df/2;	x2=x1+hg/2;
	y0=0;	y1=hg/2;	y2=hg;

	intersection()
	{
	   	cylinder(h=hg, r1=drive_diameter/2 + 1, r2=rd0, $fn=60, center=false);
		rotate_extrude(convexity=10, $fn=6*round(df*PI/6/0.5))
		polygon([ [x0,y0],[x1,y0],[x2,y1],[x1,y2],[x0,y2] ]);
	}
}

module countersunk_head(hg,df)
{
	rd0=df/2/sin(60);
	x0=0;	x1=df/2;	x2=x1+hg/2;
	y0=0;	y1=hg/2;	y2=hg;

	intersection()
	{
	   cylinder(h=hg, r1=rd0, r2=thread_outer_diameter/2-0.5, $fn=60, center=false);

		rotate_extrude(convexity=10, $fn=6*round(df*PI/6/0.5))
		polygon([ [x0,y0],[x1,y0],[x2,y1],[x1,y2],[x0,y2] ]);
	}
}

/* Library included below to allow customizer functionality
 *
 * polyScrewThread_r1.scad    by aubenc @ Thingiverse
 *
 * Modified by mike_mattala @ Thingiverse 1/1/2017 to remove deprecated assign
 *
 * This script contains the library modules that can be used to generate
 * threaded rods, screws and nuts.
 *
 * http://www.thingiverse.com/thing:8796
 *
 * CC Public Domain
 */

module screw_thread(od,st,lf0,lt,rs,cs)
{
    or=od/2;
    ir=or-st/2*cos(lf0)/sin(lf0);
    pf=2*PI*or;
    sn=floor(pf/rs);
    lfxy=360/sn;
    ttn=round(lt/st+1);
    zt=st/sn;

    intersection()
    {
        if (cs >= -1)
        {
           thread_shape(cs,lt,or,ir,sn,st);
        }

        full_thread(ttn,st,sn,zt,lfxy,or,ir);
    }
}

module hex_nut(df,hg,sth,clf,cod,crs)
{

    difference()
    {
        hex_head(hg,df);

        hex_countersink_ends(sth/2,cod,clf,crs,hg);

        screw_thread(cod,sth,clf,hg,crs,-2);
    }
}

module hex_screw(od,st,lf0,lt,rs,cs,df,hg,ntl,ntd)
{
    ntr=od/2-(st/2)*cos(lf0)/sin(lf0);
echo ("thread inner diameter", ntr*2);
    union()
    {
        hex_head(hg,df);

        translate([0,0,hg])
        if ( ntl == 0 )
        {
            cylinder(h=0.01, r=ntr, center=true);
        }
        else
        {
            if ( ntd == -1 )
            {
//!!!!!!!! HACK: rounded cylinder on one end of tbe cylinder
                rotate ([180,0,0]) translate ([0,0,-ntl-0.1])
                rcylinder(h=ntl+0.1, r=ntr, $fn=floor(od*PI/rs), b=2, center=false);
//!!!!!!!! HACK: double ended rounded blanks (top added)
                translate ([0,0,lt+ntl-0.1])
                rcylinder(h=ntl+0.1, r=ntr, $fn=floor(od*PI/rs), b=2, center=false);
            }
            else if ( ntd == 0 )
            {
                union()
                {
                    cylinder(h=ntl-st/2,
                             r=od/2, $fn=floor(od*PI/rs), center=false);

                    translate([0,0,ntl-st/2])
                    cylinder(h=st/2,
                             r1=od/2, r2=ntr,
                             $fn=floor(od*PI/rs), center=false);
                }
            }
            else
            {
                cylinder(h=ntl, r=ntd/2, $fn=ntd*PI/rs, center=false);
            }
        }

        translate([0,0,ntl+hg]) screw_thread(od,st,lf0,lt,rs,cs);

    }
}
// !!!!!!!!!!!!!!!!!!!! HACK: add
module rcylinder(r=10,h=10,b=2)
{
    r1=r;
    {translate([0,0,0])
    hull(){
        rotate_extrude()
        translate([r-b,h-b,0]) intersection () { circle(r = b); square(b); }
        rotate_extrude()
        translate([r-b/2, 0, 0]) square([b]);}
        }
    }

module hex_screw_0(od,st,lf0,lt,rs,cs,df,hg,ntl,ntd)
{
    ntr=od/2-(st/2)*cos(lf0)/sin(lf0);

    union()
    {
        hex_head_0(hg,df);

        translate([0,0,hg])
        if ( ntl == 0 )
        {
            cylinder(h=0.01, r=ntr, center=true);
        }
        else
        {
            if ( ntd == -1 )
            {
                cylinder(h=ntl+0.01, r=ntr, $fn=floor(od*PI/rs), center=false);
            }
            else if ( ntd == 0 )
            {
                union()
                {
                    cylinder(h=ntl-st/2,
                             r=od/2, $fn=floor(od*PI/rs), center=false);

                    translate([0,0,ntl-st/2])
                    cylinder(h=st/2,
                             r1=od/2, r2=ntr,
                             $fn=floor(od*PI/rs), center=false);
                }
            }
            else
            {
                cylinder(h=ntl, r=ntd/2, $fn=ntd*PI/rs, center=false);
            }
        }

        translate([0,0,ntl+hg]) screw_thread(od,st,lf0,lt,rs,cs);
    }
}

module thread_shape(cs,lt,or,ir,sn,st)
{
    if ( cs == 0 )
    {
        cylinder(h=lt, r=or, $fn=sn, center=false);
    }
    else
    {
        union()
        {
            translate([0,0,st/2])
              cylinder(h=lt-st+0.005, r=or, $fn=sn, center=false);

            if ( cs == -1 || cs == 2 )
            {
                cylinder(h=st/2, r1=ir, r2=or, $fn=sn, center=false);
            }
            else
            {
                cylinder(h=st/2, r=or, $fn=sn, center=false);
            }

            translate([0,0,lt-st/2])
            if ( cs == 1 || cs == 2 )
            {
                  cylinder(h=st/2, r1=or, r2=ir, $fn=sn, center=false);
            }
            else
            {
                cylinder(h=st/2, r=or, $fn=sn, center=false);
            }
        }
    }
}

module full_thread(ttn,st,sn,zt,lfxy,or,ir)
{
  if(ir >= 0.2)
  {
    for(i=[0:ttn-1])
    {
        for(j=[0:sn-1])
        {
			pt = [[0,0,i*st-st],
                 [ir*cos(j*lfxy),     ir*sin(j*lfxy),     i*st+j*zt-st       ],
                 [ir*cos((j+1)*lfxy), ir*sin((j+1)*lfxy), i*st+(j+1)*zt-st   ],
				 [0,0,i*st],
                 [or*cos(j*lfxy),     or*sin(j*lfxy),     i*st+j*zt-st/2     ],
                 [or*cos((j+1)*lfxy), or*sin((j+1)*lfxy), i*st+(j+1)*zt-st/2 ],
                 [ir*cos(j*lfxy),     ir*sin(j*lfxy),     i*st+j*zt          ],
                 [ir*cos((j+1)*lfxy), ir*sin((j+1)*lfxy), i*st+(j+1)*zt      ],
                 [0,0,i*st+st]];

            polyhedron(points=pt,faces=[[1,0,3],[1,3,6],[6,3,8],[1,6,4], //changed triangles to faces (to be deprecated)
										[0,1,2],[1,4,2],[2,4,5],[5,4,6],[5,6,7],[7,6,8],
										[7,8,3],[0,2,3],[3,2,7],[7,2,5]	]);
        }
    }
  }
  else
  {
    echo("Step Degrees too agresive, the thread will not be made!!");
    echo("Try to increase de value for the degrees and/or...");
    echo(" decrease the pitch value and/or...");
    echo(" increase the outer diameter value.");
  }
}

module hex_head(hg,df)
{
	rd0=df/2/sin(60);
	x0=0;	x1=df/2;	x2=x1+hg/2;
	y0=0;	y1=hg/2;	y2=hg;

	intersection()
	{
	   cylinder(h=hg, r=rd0, $fn=facets, center=false);

		rotate_extrude(convexity=10, $fn=6*round(df*PI/6/0.5))
		polygon([ [x0,y0],[x1,y0],[x2,y1],[x1,y2],[x0,y2] ]);
	}
}

module hex_head_0(hg,df)
{
    cylinder(h=hg, r=df/2/sin(60), $fn=6, center=false);
}

module hex_countersink_ends(chg,cod,clf,crs,hg)
{
    translate([0,0,-0.1])
    cylinder(h=chg+0.01,
             r1=cod/2,
             r2=cod/2-(chg+0.1)*cos(clf)/sin(clf),
             $fn=floor(cod*PI/crs), center=false);

    translate([0,0,hg-chg+0.1])
    cylinder(h=chg+0.01,
             r1=cod/2-(chg+0.1)*cos(clf)/sin(clf),
             r2=cod/2,
             $fn=floor(cod*PI/crs), center=false);
}
```