[User]
I'd like to create a customizable 2D origami snowman design, similar to the one I saw on Thingiverse. I need it to be parametric, so I can adjust several key aspects.

Specifically, I want to be able to control:

*   The maximum overall size of the design. The design should scale proportionally, so if I set the max size to, say, 150mm, the longer side will be 150mm, and the other dimension will scale accordingly.
*   The model's height (thickness). This would be for 3D printing.
*   The thickness of the outer outline.
*   The thickness of the inner outlines.
*   The radius of the roundness at the ends of the inner outlines.
*   Whether to mirror the model, effectively flipping it along the vertical axis.

The design itself is based on a set of coordinates for the outer perimeter and for internal cutouts, which I've included below.  The design involves an outer polygon, with a number of smaller polygonal cutouts inside.  I need these to be implemented parametrically.

```
// Outer Points
A1 = [714, 1322];
A2 = [663, 1284];
A3 = [570, 1125];
A4 = [557, 1057];
A5 = [654, 884];
A6 = [583, 756];
A7 = [585, 644];
A8 = [348, 570];
A9 = [356, 538];
A10 = [603, 613];
A11 = [661, 511];
A12 = [686, 509];
A13 = [620, 391];
A14 = [650, 294];
A15 = [700, 202];
A16 = [717, 199];
A17 = [854, 197];
A18 = [909, 197];
A19 = [981, 316];
A20 = [970, 385];
A21 = [906, 506];
A22 = [926, 504];
A23 = [980, 593];
A24 = [1278, 501];
A25 = [1296, 518];
A26 = [1002, 622];
A27 = [1012, 646];
A28 = [1017, 747];
A29 = [949, 883];
A30 = [1048, 1051];
A31 = [1050, 1117];
A32 = [967, 1274];
A33 = [903, 1321];

outline = [A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33];

// Inner Points
B1 = [798, 904];
B2 = [792, 772];
B3 = [930, 673];
B4 = [654, 676];
B5 = [622, 652];
B6 = [640, 622];
B7 = [961, 635];
B8 = [950, 602];
B9 = [957, 1183];
B10 = [644, 1182];
B11 = [795, 1093];
B12 = [779, 514];
B13 = [707, 525];
B14 = [880, 524];
B15 = [772, 396];
B16 = [888, 322];
B17 = [665, 320];

// Polygons
C1 = [A13, A14, A15, A16, B17];
C2 = [A16, A17, B16, B15, B17];
C3 = [A17, A18, A19, A20, B16];
C4 = [B16, A20, A21, B12, B15];
C5 = [B17, B15, B12, A12, A13];
C6 = [A11, A12, B12, A21, A22, B14, B13];
C7 = [A11, A10, B6, B5, A7, A6, B4, B13];
C8 = [B13, B14, B3, B2, B4];
C9 = [B14, A22, A23, B8, B7, A26, A27, A28, B3];
C10 = [B3, A28, A29, B1, B2];
C11 = [B4, B2, B1, A5, A6];
C12 = [B1, B11, B9, A30, A29];
C13 = [A30, A31, A32, A33, B9];
C14 = [B11, B9, A33, A1, B10];
C15 = [B10, A1, A2, A3, A4];
C16 = [A4, A5, B1, B11, B10];
C17 = [B8, A23, A24, A25, A26, B7];
C18 = [A9, A10, B6, B5, A7, A8];

cut_polygons = [C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18];
```

The code should generate a single `.scad` file that, when rendered, shows a flat snowman design with the cutouts. I also need the `create` module. It should use `linear_extrude`, `difference`, and `offset`. I am looking for a single `.scad` file, not multiple, and I don't need any special libraries, like MCAD or BOSL.

[Assistant]
customizable_origami_snowman.scad:
```
/*
 * Customizable Origami - Snowman - https://www.thingiverse.com/thing:2759937
 * by Dennis Hofmann - https://www.thingiverse.com/mightynozzle/about
 * created 2018-01-17
 * version v1.0
 *
 * Changelog
 * --------------
 * v1.0:
 *      - final design
 * --------------
 *
 * This work is licensed under the Creative Commons - Attribution - NonCommercial - ShareAlike license.
 * https://creativecommons.org/licenses/by-nc-sa/3.0/
 */

 // Parameter Section //
//-------------------//

// preview[view:north, tilt:top]

// The maximum size of the longest side. The shorter side will be automatically resized in same ratio.
max_size_in_millimeter = 120; //[20:300]

// The height of the model.
model_height_in_millimeter = 5; //[0.2:0.2:100]

// Thickness of the outer outline.
outline_size_in_millimeter = 1.8; //[0.5:0.1:20]

// Thickness of the inner outline.
inline_size_in_millimeter = 0.9; //[0.5:0.1:20]

// Roundiness of the ends of the inner outlines.
inline_edge_radius_in_millimeter = 0.5; //[0.0:0.1:5]

// Flip model
flip_model = "no"; //[yes,no]

/*[hidden]*/
max_size = max_size_in_millimeter;
model_height = model_height_in_millimeter;
$fn=32;

// Outer Points
A1 = [714, 1322];
A2 = [663, 1284];
A3 = [570, 1125];
A4 = [557, 1057];
A5 = [654, 884];
A6 = [583, 756];
A7 = [585, 644];
A8 = [348, 570];
A9 = [356, 538];
A10 = [603, 613];
A11 = [661, 511];
A12 = [686, 509];
A13 = [620, 391];
A14 = [650, 294];
A15 = [700, 202];
A16 = [717, 199];
A17 = [854, 197];
A18 = [909, 197];
A19 = [981, 316];
A20 = [970, 385];
A21 = [906, 506];
A22 = [926, 504];
A23 = [980, 593];
A24 = [1278, 501];
A25 = [1296, 518];
A26 = [1002, 622];
A27 = [1012, 646];
A28 = [1017, 747];
A29 = [949, 883];
A30 = [1048, 1051];
A31 = [1050, 1117];
A32 = [967, 1274];
A33 = [903, 1321];

outline = [A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33];

// Inner Points
B1 = [798, 904];
B2 = [792, 772];
B3 = [930, 673];
B4 = [654, 676];
B5 = [622, 652];
B6 = [640, 622];
B7 = [961, 635];
B8 = [950, 602];
B9 = [957, 1183];
B10 = [644, 1182];
B11 = [795, 1093];
B12 = [779, 514];
B13 = [707, 525];
B14 = [880, 524];
B15 = [772, 396];
B16 = [888, 322];
B17 = [665, 320];

// Polygons
C1 = [A13, A14, A15, A16, B17];
C2 = [A16, A17, B16, B15, B17];
C3 = [A17, A18, A19, A20, B16];
C4 = [B16, A20, A21, B12, B15];
C5 = [B17, B15, B12, A12, A13];
C6 = [A11, A12, B12, A21, A22, B14, B13];
C7 = [A11, A10, B6, B5, A7, A6, B4, B13];
C8 = [B13, B14, B3, B2, B4];
C9 = [B14, A22, A23, B8, B7, A26, A27, A28, B3];
C10 = [B3, A28, A29, B1, B2];
C11 = [B4, B2, B1, A5, A6];
C12 = [B1, B11, B9, A30, A29];
C13 = [A30, A31, A32, A33, B9];
C14 = [B11, B9, A33, A1, B10];
C15 = [B10, A1, A2, A3, A4];
C16 = [A4, A5, B1, B11, B10];
C17 = [B8, A23, A24, A25, A26, B7];
C18 = [A9, A10, B6, B5, A7, A8];

cut_polygons = [C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, C14, C15, C16, C17, C18];

min_x = A8[0];
min_y = A17[1];
max_x = A25[0];
max_y = A1[1];

x_size = max_x - min_x;
y_size = max_y - min_y;

x_factor = max_size / x_size;
y_factor = max_size / y_size;

inline_size = x_size > y_size ? inline_size_in_millimeter / x_factor / 2: inline_size_in_millimeter / y_factor / 2;
inline_edge_radius = x_size > y_size ? inline_edge_radius_in_millimeter / x_factor: inline_edge_radius_in_millimeter / y_factor;
outline_size = x_size > y_size ? outline_size_in_millimeter / x_factor - inline_size: outline_size_in_millimeter / y_factor - inline_size;

 // Program Section //
//-----------------//

if(x_size > y_size) {
    resize(newsize=[max_size, x_factor * y_size, model_height]){
        if(flip_model == "yes") {
            mirror([0,1,0]) {
                rotate([180,180,0]) {
                    create(outline, cut_polygons);
                }
            }
        } else {
            create(outline, cut_polygons);
        }
    }
} else {
    resize(newsize=[y_factor * x_size, max_size, model_height]){
        if(flip_model == "yes") {
            mirror([0,1,0]) {
                rotate([180,180,0]) {
                    create(outline, cut_polygons);
                }
            }
        } else {
            create(outline, cut_polygons);
        }
    }
}

 // Module Section //
//----------------//

module create() {
    linear_extrude(height=1) {
        difference() {
            offset(r = -0) {
                offset(r = +outline_size) {
                    polygon(points = outline, convexity = 10);
                }
            }

            for(cut_polygon = [0:len(cut_polygons)]) {
                offset(r = +inline_edge_radius) {
                    offset(r = -inline_size - inline_edge_radius) {
                        polygon(points = cut_polygons[cut_polygon], convexity = 10);
                    }
                }
            }
        }
    }
}

```


[User]
Hey, I'd like to make some personalized toy coins for my kid. I've got a basic design in mind, but I need your help to turn it into a parametric OpenSCAD file, or maybe a couple of them if that makes more sense.

The basic idea is a cylindrical coin with a letter cut out of the center. Here are the things I'd like to be able to control:

*   **Letter:** The character that's cut out of the coin (should be a single character).
*   **Font Size:**  The size of that letter to make sure it fits within the coin nicely.
*   **Font Name:**  The typeface of the letter. I'd like the usual fonts like "Arial" but the ability to change is important.
*   **Coin Diameter:** The overall diameter of the coin.
*   **Coin Height:**  The thickness of the coin.
*   **Rim Thickness:** The thickness of the raised rim around the edge of the coin.
*   **Center Connector Thickness:** There should be a small "connection" of material from the letter to the inner ring of the coin. This determines the size of that connection.
*   **Number of Sides:** The smoothness of the coin. The more sides, the smoother the coin. (should be passed to $fn)

The coin should have a raised rim on both the top and the bottom, and the cut-out letter should be sunken in on both sides by the same amount. It'll also need the center connector.

I'm not looking for any fancy features beyond that. Just a solid, simple, parametric coin I can customize. I don't need any library functions, please.

[Assistant]
Coin_V4.scad:
```
//The letter to cut out in the middle of the coin
Letter="J";

//Font size, so that one letter fits on the coin
Fontsize=20;

//Font name
fontname="Arial";

//Diameter of the coin
dia=38;

//height of the coin
height=14;

//outer rim thickness of the coin
rand=2;

//connecting plastic in the middle of the coin
connectorthickness=2;

//accuracy of the coin
$fn=50;

/* [Hidden] */
//-------------------

sink_letter=height/2-connectorthickness/2;

/*
Customizable cash register coin

Version 3, January 2018
Written by MC Geisler (mcgenki at gmail dot com)

License: Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0)
You are free to:
    Share - copy and redistribute the material in any medium or format
    Adapt - remix, transform, and build upon the material
Under the following terms:
    Attribution - You must give appropriate credit, provide a link to the license, and indicate if changes were made.
    You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
    NonCommercial - You may not use the material for commercial purposes.
    ShareAlike - If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.
*/

module ring()
{
    difference()
    {
        cylinder(d=dia-2*rand, h=rand);
        translate([0,0,-.1])
            cylinder(d=dia-4*rand, h=rand);
    }
}

module Writeletter()
{
    linear_extrude(height=sink_letter,convexity = 10)
        text(Letter,size=Fontsize,font=fontname,halign="center",valign="center");
}

difference()
{
    cylinder(d=dia, h=height);

    translate([0,0,-.1])
        ring();

    translate([0,0,height-rand+.1])
        ring();

    translate([0,0,-.1])
        scale([-1,1,1])
            Writeletter();

    translate([0,0,height-sink_letter+.1])
        Writeletter();

}
```


[User]
I'd like to design a customizable ice wheel for a 1/10 scale Traxxas Rustler RC car, or similar, that can be 3D printed. I want to be able to adjust things like the overall wheel diameter and width, the size of the opening for the hub, and most importantly, the size and arrangement of the claws for gripping ice.

Here are the specific parameters I envision being able to control:

*   **`coreWheelDia`**: The diameter of the wheel *without* the claws. Range should be between 80 and 150mm.
*   **`coreWheelWidth`**: The width of the wheel. It needs to be wider than the sum of  `hubClearanceDepth`, `hexInsertDepth`, and `spindleShaftHoleThickness`. The range should be between 30 and 100mm.
*   **`tireEdgeRoundOffRadius`**: How much the edges of the wheel are rounded. Range: 1 to 10mm.
*   **`hubClearanceInnerDia`**: The diameter of the opening on the backside of the wheel for hub clearance. Must be less than `coreWheelDia`. Range should be between 60 and 140mm.
*   **`hubClearanceDepth`**: The depth of the hub clearance opening. Range: 15 to 35mm.
*   **`hexInsertDia`**: The point-to-point measurement of the hex insert for mounting to the car. Range: 10 to 20mm.
*   **`hexInsertDepth`**: The depth of the hex insert. Range: 3 to 6mm.
*  **`spindleShaftDia`**: The diameter of the axle-shaft hole. Range: 3 to 8mm.
*  **`spindleShaftHoleThickness`**: The thickness of the wheel around the axle-shaft hole. Range: 3 to 6mm.
*   **`nutFlatDia`**: The diameter of the flat area where the axle nut tightens. Range: 10 to 20mm.
*   **`clawBaseDia`**: The diameter of the base of each claw where it meets the wheel surface. Range: 4 to 14mm.
*   **`clawLength`**: The length of the claws (how much they slope down to the surface of the wheel). Range: 8 to 18mm.
*   **`clawsPerRow`**: The number of claws in a single row around the circumference of the wheel. Range: 6 to 40.
*   **`clawRows`**: The number of rows of claws. Range: 2 to 6.
*   **`numberOfSpokes`**: The number of spokes/slots in the wheel.  Should be a limited set of options: 4, 5, or 6 spokes.
*   **`spokeCornerRoundnessDia`**: How much the corners of the spoke slots are rounded off. Range: 1 to 10mm.
*   **`spokeHubDia`**:  The diameter of the solid hub area in the center of the wheel. Range: 20 to 80mm.
*   **`spokeSlotInset`**: How much space to leave between the outside of the spoke-slots and the edge of the wheel.  Range should be 0 to 20mm.

I'd like the main wheel body to be a cylinder with rounded edges, then cut out the hub clearance, hex insert, axle hole, and spokes. The claws should be created with cones, arranged in concentric rows.  I'd prefer it if you didn't use any external libraries to achieve this design.

[Assistant]
traxxas_ice_wheel_rear.scad:
```
// Ice Wheel for 1/10 Traxxas Rustler (maybe others) - Rear

//CUSTOMIZER VARIABLES

// Diameter of the wheel without the claws:
coreWheelDia=110; // [80:150]

// Width of the wheel (needs to be larger than hubClearanceDepth + hexInsertDepth + spindleShaftHoleThickness):
coreWheelWidth=50; // [30:100]

// How much the edge of the wheel is "rounded off"
tireEdgeRoundOffRadius=5; // [1:10]

// The size of the opening on the inside / back-side of the wheel (needs to be smaller than coreWheelDia):
hubClearanceInnerDia=80; // [60:140]

// The depth of the opening on the inside/back-side of the wheel:
hubClearanceDepth=25; // [15:35]

// Measurement from point to point of the hex insertion recess:
hexInsertDia=15; // [10:20]

// Depth of the hex insertion recess:
hexInsertDepth=4; // [3:6]

// Diameter of the axle-shaft hole:
spindleShaftDia=5; // [3:8]

// Thickness of the wheel around the axle-shaft hole:
spindleShaftHoleThickness=4; // [3:6]

// Diameter of the flat area (where the axle-nut tightens down):
nutFlatDia=12; // [10:20]

// How tall the claws are from the wheel surface:
clawBaseDia=10; // [4:14]

// How long the claws slope into the wheel surface:
clawLength=15; // [8:18]

// How many claws go in each row:
clawsPerRow=15; // [6:40]

// How many rows of claws:
clawRows=4; // [2:6]

// How many spokes (or spoke slots... same thing):
numberOfSpokes=5; // [4,5,6]

// How much the corners of the spoke-slots are "rounded off":
spokeCornerRoundnessDia=5; // [1:10]

// How much solid space to reserve in the center of the wheel:
spokeHubDia=30; // [20:80]

// How much solid space to reserve outside the spoke-slots:
spokeSlotInset=3; // [0:20]

//CUSTOMIZER VARIABLES END

overlap=0.01*1;

$fn=50*1;

outerConeDepth=coreWheelWidth
        -hubClearanceDepth
        -hexInsertDepth
        -spindleShaftHoleThickness;

union() {
    difference() {
        translate([0,0,tireEdgeRoundOffRadius]) {
            minkowski() {
                cylinder(d=coreWheelDia-tireEdgeRoundOffRadius*2,
                    h=coreWheelWidth-tireEdgeRoundOffRadius*2);
                sphere(r=tireEdgeRoundOffRadius);
            }
        }
        translate([0,0,coreWheelWidth-hubClearanceDepth])
            cylinder(d=hubClearanceInnerDia,
                h=hubClearanceDepth+overlap);
        translate([0,0,
                coreWheelWidth-hubClearanceDepth-hexInsertDepth])
            cylinder(d=hexInsertDia,
                h=hexInsertDepth+overlap, $fn=6);
        translate([0,0,-overlap])
            cylinder(d=spindleShaftDia, h=coreWheelWidth+overlap*2);
        translate([0,0,-overlap])
            cylinder(d1=hubClearanceInnerDia, d2=nutFlatDia,
            h=outerConeDepth+overlap);
        spokeCutouts();
    }
    // Claws
    clawSeparationAngle=360/clawsPerRow;
    clawRowOffset=coreWheelWidth/(clawRows+1);
    for(r=[1:clawRows]) {
        for (s=[1:clawsPerRow]) {
            rotate([0,0,
                clawSeparationAngle*s
                + ((r%2 != 0) ? 0 : clawSeparationAngle/2)])
            translate([coreWheelDia/2-overlap, 0,
                    clawRowOffset*r])
                rotate([0,90,((r%2 !=0) ? -1 : 1)*100])
                    cylinder(d1=clawBaseDia,d2=0,
                        h=clawLength,
                        $fn=4);
        }
    }

}

module spokeCutouts() {
    // Spokes
    // Note: Spoke material is same size as spoke opening
    spokeHalfAngle=360/numberOfSpokes/4;
    for (s=[0:numberOfSpokes-1]) {
        rotate([0,0,s*(spokeHalfAngle*4)])
        hull() {
            // inner
            rotate([0,0,-spokeHalfAngle])
                translate([(spokeHubDia+spokeCornerRoundnessDia)/2
                        ,0,0])
                    cylinder(d=spokeCornerRoundnessDia,
                        h=coreWheelWidth);
            rotate([0,0,spokeHalfAngle])
                translate([(spokeHubDia+spokeCornerRoundnessDia)/2
                        ,0,0])
                    cylinder(d=spokeCornerRoundnessDia,
                        h=coreWheelWidth);
            // outer
            rotate([0,0,-spokeHalfAngle])
                translate([(hubClearanceInnerDia-
                        spokeCornerRoundnessDia)/2-spokeSlotInset,
                                0,0])
                    cylinder(d=spokeCornerRoundnessDia,
                        h=coreWheelWidth);
            rotate([0,0,spokeHalfAngle])
                translate([(hubClearanceInnerDia
                        -spokeCornerRoundnessDia)/2-spokeSlotInset,
                            0,0])
                    cylinder(d=spokeCornerRoundnessDia,
                        h=coreWheelWidth);
        }
    }
}
```


[User]
I'd like to design a parametric USB stick stand, something like the design in the provided SCAD file. Basically, it should consist of a series of slots to hold USB sticks, arranged side-by-side on a base.

The stand should have a variable number of USB stick slots, determined by a "Numbers" parameter which should be a whole number. Each slot should be designed to hold a typical USB stick, with the dimensions defined by 'USBlength' and 'USBwidth'. The base the slots sit on should have dimensions 'BASElength' and 'BASEwidth'. The code should include modules called STAND, USB, RADIUS, TOP, TEXT, and AE, similar to the provided file.

The 'STAND' module should handle the overall structure, rotating it, calling 'RADUIS' to create the rounded ends of the base, and then create slots for each USB stick using the 'USB' and 'TOP' modules. The 'USB' module should create the slot shape using `difference` to cut out the negative space for the USB stick. The 'RADIUS' module should create the rounded end shape using a cylinder with some material removed. The 'TOP' module is just a block sitting on the base, it's a 5mm thick block.

There should also be some text added to the design; the 'TEXT' module should put the word 'USB' onto the stand, and the 'AE' module should add the letter "Æ" on one of the rounded end pieces. Use a standard font like "Arial" for the 'TEXT' and "Bradley Hand ITC" for 'AE'. These text elements should also be positioned using transforms on the 'STAND' module, like the existing design. I'm thinking about a height of 4 for the `linear_extrude` in `TEXT`, and 10 in `AE`.

Could you create a new OpenSCAD file with all of these parameters and modules defined? It's important that it's parametric so I can change the number of slots easily. I don't need it to use any external libraries.

[Assistant]
USBstand_V2.3.scad:
```
// variable description
/*[Number_off_Sticks]*/
Numbers=5; // [2,3,4,5,6]

/*
|========================================
|
|Design:          USBstand
|Made by:       Æxperibox
|Date:             17/01/2018
|
|========================================
*/

/***************** Basics ******************
Shapes
    cube([0, 0, 0]);        x,y,z
    sphere(r);
    cylinder(h, r1, r2);

Transformations
    translate([0, 0, 0])    x,y,z
    scale([0, 0, 0])        x,y,z
    rotate([0, 0, 0])       x,y,z

CSG Operations
(Constructive Solid Geometry Operations)
    union() { }
   difference() { }
    intersection() { }

Special variables:
$fa is the minimum angle for a fragment     (default 12)
$fs is the minimum size of a fragment.      (default  2)
$fn is the number of fragments              (default  0)
    If $fn > 0  $fs and $fa are ignored
    ex: $fn=150;

Functions:
    Add Rounding:
            minkowski(){
                PlaceObjectHere
                sphere OR cylinder
            }

    Add Text:
            linear_extrude(height = 4) {
            text("MYTEXT", font = "arial", size = 5);
            }

*********************************************/

//Parameters

$fn=50;

    Text="Æ";
    USBlength=12.5;
    USBwidth=5;
    BASElength=25;
    BASEwidth=13;

//Renders

      union() {
        difference() {
            STAND();
                translate([Numbers, 1.3*BASEwidth+6, BASEwidth])
                    rotate([90,0, 0])
                        AE();
        }
        translate([4*Numbers-BASEwidth, 1.3*BASEwidth, 4])
                rotate([180,0, 0])
                    TEXT();
    }

//Modules

    module STAND(){
         rotate([90, 0, 0]){
    translate([0,0,-BASEwidth+5])
        RADUIS();

    translate([Numbers*BASEwidth,0,-BASEwidth+5])
        rotate([0, 180, 0])
            RADUIS();

    for (i = [0 :Numbers-1]){
        translate([i*BASEwidth,0, 0])USB();
            translate([i*BASEwidth,0, -BASEwidth*2+5])TOP();
            }
        }
    }

    module USB(){
        difference() {
            cube([BASEwidth,BASElength,5]);
                translate([0.5*BASEwidth-0.5*USBwidth, 0.5*BASElength-0.5*USBlength, -1])
                    cube([USBwidth, USBlength, 7]);
        }
    }

    module RADUIS(){
        rotate([-90, 0, 0])
           union() {
                rotate([0, 0, 0]){
                    difference() {
                        cylinder(BASElength, BASEwidth, BASEwidth);
                         translate([0,0,-1])
                            cylinder(BASElength*1.1, BASEwidth-5, BASEwidth-5);
                                translate([0, -BASEwidth, -BASElength*0.1])
                                    cube([BASEwidth*2, BASEwidth*2, BASElength*1.2]);
                }
            }
        }
    }

    module TOP(){
         cube([BASEwidth, BASElength, 5]);
    }

      module TEXT(){
  linear_extrude(height = 4) {
        text("USB", font ="Arial", size = 1.35*BASEwidth,  spacing = 0.2*Numbers );
            sphere(1);
    }
}

  module AE(){
  linear_extrude(height = 10) {
        text(Text, font ="Bradley Hand ITC", size = BASEwidth,  spacing = 1 );

    }
}
```


[User]
I'm looking to design a parametric ice wheel for a Traxxas Rustler, specifically for the front, that I can 3D print. It needs to have skate-blade type treads for steering on ice. I've seen some good ones online, but I want something fully customizable.

Here's what I'm thinking for the design parameters:

*   **Overall Wheel Dimensions:**
    *   `coreWheelDia`: The diameter of the wheel itself, not including the treads. I'd like this to range from 80mm to 150mm.
    *   `coreWheelWidth`: The total width of the wheel, with a range of 30mm to 100mm.
    *   `tireEdgeRoundOffRadius`: The radius of the rounded edge of the wheel, adjustable from 1mm to 10mm.

*   **Hub and Mounting:**
    *   `hubClearanceInnerDia`: The diameter of the recessed opening on the back of the wheel. This should be adjustable from 60mm to 140mm.
    *   `hubClearanceDepth`: The depth of that recessed opening, from 15mm to 35mm.
    *   `hexInsertDia`: The diameter of the hex-shaped recess for the wheel hub, ranging from 10mm to 20mm.
    *  `hexInsertDepth`: The depth of the hex insertion recess, with a range from 3mm to 6mm.
    *   `spindleShaftDia`: The diameter of the axle-shaft hole, adjustable from 3mm to 8mm.
    *   `spindleShaftHoleThickness`: The thickness of the material surrounding the axle-shaft hole, between 3mm and 6mm.
     *  `nutFlatDia`: The diameter of the flat area on the front of the wheel where the axle nut tightens, from 10mm to 20mm.

*   **Skate Blade Treads:**
    *   `skateBladeWidth`: The width of each skate blade where it connects to the wheel, from 2mm to 8mm.
    *   `skateBladeDepth`: How much the blades extend out from the wheel, ranging from 5mm to 15mm.
    *   `skateBlades`: The number of skate blades around the wheel.  I'd like to be able to choose between 2 and 6 blades.

*   **Spokes/Slot Design:**
    *   `numberOfSpokes`: The number of spokes (or slots between the spokes), selectable from 4, 5, or 6.
    *   `spokeCornerRoundnessDia`: The diameter used for rounding the corners of the spoke slots.  Adjustable from 1mm to 10mm.
    *   `spokeHubDia`: The diameter of the central solid area where the spokes connect, from 20mm to 80mm.
    *   `spokeSlotInset`:  How far the spoke slots are inset from the outer edge of the wheel, ranging from 0mm to 20mm.

I'd like the design to use a minkowski sum for the rounded wheel edges and hull() for the spoke cutouts. For the blades, a rotate_extrude of a polygon seems like the right approach. I'd like each of these to be separate modules.

Could you generate the OpenSCAD files for this? I'm hoping to be able to easily customize these parameters for different prints. It looks like it might help to have the BOSL2 library included, particularly for the parametric design aspects and the minkowski function.

[Assistant]
traxxas_ice_wheel_front.scad:
```
// Ice Wheel for Traxxas Rustler - Front
// This is optimized for steering on a rear-wheel-drive

// CUSTOMIZER VARIABLES

// Diameter of the wheel without the claws:
coreWheelDia=100;   // [80:150]

// Width of the wheel (needs to be larger than hubClearanceDepth + hexInsertDepth + spindleShaftHoleThickness):
coreWheelWidth=50; // [30:100]

// How much the edge of the wheel is "rounded off"
tireEdgeRoundOffRadius=5; // [1:10]

// The size of the opening on the inside / back-side of the wheel (needs to be smaller than coreWheelDia):
hubClearanceInnerDia=70; // [60:140]

// The depth of the opening on the inside/back-side of the wheel:
hubClearanceDepth=25; // [15:35]

// Measurement from point to point of the hex insertion recess:
hexInsertDia=15; // [10:20]

// Depth of the hex insertion recess:
hexInsertDepth=4; // [3:6]

// Diameter of the axle-shaft hole:
spindleShaftDia=5; // [3:8]

// Thickness of the wheel around the axle-shaft hole:
spindleShaftHoleThickness=4; // [3:6]

// Diameter of the flat area (where the axle-nut tightens down):
nutFlatDia=12; // [10:20]

// How wide the blades are where they attach to the wheel:
skateBladeWidth=5; // [2:8]

// How tall the skate blades are from the wheel:
skateBladeDepth=10; // [5:15]

// How many skate blades to include:
skateBlades=4; // [2:6]

// How many spokes (or spoke slots... same thing):
numberOfSpokes=5; // [4,5,6]

// How much the corners of the spoke-slots are "rounded off":
spokeCornerRoundnessDia=5; // [1:10]

// How much solid space to reserve in the center of the wheel:
spokeHubDia=30; // [20:80]

// How much solid space to reserve outside the spoke-slots:
spokeSlotInset=3; // [0:20]

//CUSTOMIZER VARIABLES END

overlap=0.01*1;

$fn=50*1;

outerConeDepth=coreWheelWidth
        -hubClearanceDepth
        -hexInsertDepth
        -spindleShaftHoleThickness;

union() {
    difference() {
        translate([0,0,tireEdgeRoundOffRadius]) {
            minkowski() {
                cylinder(d=coreWheelDia-tireEdgeRoundOffRadius*2,
                    h=coreWheelWidth-tireEdgeRoundOffRadius*2);
                sphere(r=tireEdgeRoundOffRadius);
            }
        }
        translate([0,0,coreWheelWidth-hubClearanceDepth])
            cylinder(d=hubClearanceInnerDia,
                h=hubClearanceDepth+overlap);
        translate([0,0,
                coreWheelWidth-hubClearanceDepth-hexInsertDepth])
            cylinder(d=hexInsertDia,
                h=hexInsertDepth+overlap, $fn=6);
        translate([0,0,-overlap])
            cylinder(d=spindleShaftDia, h=coreWheelWidth+overlap*2);
        translate([0,0,-overlap])
            cylinder(d1=hubClearanceInnerDia, d2=nutFlatDia,
            h=outerConeDepth+overlap);
        spokeCutouts();
    }

    // Skates
    // Note: Need something to keep the wheel spinning
    skateBladeOffset=coreWheelWidth/(skateBlades+1);
    for(r=[1:skateBlades]) {
        rotate_extrude(angle=360) {
            polygon(
                points=[
                    [coreWheelDia/2-overlap,
                        skateBladeOffset*r-(skateBladeWidth/2)],
                    [coreWheelDia/2-overlap,
                        skateBladeOffset*r+(skateBladeWidth/2)],
                    [coreWheelDia/2+skateBladeDepth/3*2,
                        skateBladeOffset*r+(skateBladeWidth/2)],
                    [coreWheelDia/2+skateBladeDepth,
                        skateBladeOffset*r],
                    [coreWheelDia/2+skateBladeDepth/3*2,
                        skateBladeOffset*r-(skateBladeWidth/2)],
                    [coreWheelDia/2-overlap,
                        skateBladeOffset*r-(skateBladeWidth/2)]
                ]
            );
        }

    }

}

module spokeCutouts() {
    // Spokes
    // Note: Spoke material is same size as spoke opening
    spokeHalfAngle=360/numberOfSpokes/4;
    for (s=[0:numberOfSpokes-1]) {
        rotate([0,0,s*(spokeHalfAngle*4)])
        hull() {
            // inner
            rotate([0,0,-spokeHalfAngle])
                translate([(spokeHubDia+spokeCornerRoundnessDia)/2
                        ,0,0])
                    cylinder(d=spokeCornerRoundnessDia,
                        h=coreWheelWidth);
            rotate([0,0,spokeHalfAngle])
                translate([(spokeHubDia+spokeCornerRoundnessDia)/2
                        ,0,0])
                    cylinder(d=spokeCornerRoundnessDia,
                        h=coreWheelWidth);
            // outer
            rotate([0,0,-spokeHalfAngle])
                translate([(hubClearanceInnerDia-
                        spokeCornerRoundnessDia)/2-spokeSlotInset,
                                0,0])
                    cylinder(d=spokeCornerRoundnessDia,
                        h=coreWheelWidth);
            rotate([0,0,spokeHalfAngle])
                translate([(hubClearanceInnerDia
                        -spokeCornerRoundnessDia)/2-spokeSlotInset,
                            0,0])
                    cylinder(d=spokeCornerRoundnessDia,
                        h=coreWheelWidth);
        }
    }
}
```


[User]
Hey, I'm looking to create a simple text display in OpenSCAD, but with the text being the result of a calculation. I have a specific function evaluator in mind, and it's included in the `calc-standalone.scad` file I'm attaching (no need to generate that). It's a single file, so you won't need to worry about linking multiple files together, but you should note the comments in the code so that you can use the functions. Specifically, the `compileFunction` and `evaluateFunction` functions are what I'm interested in.

Essentially, I want the design to take a user-defined string `expression` which will be evaluated by `evaluateFunction` and display the expression and the result as a text object. The `calc-standalone.scad` file defines the necessary evaluation functions.

So, the OpenSCAD script you provide should:

1.  Take a string parameter `expression`, defaulting to something like "1+1".
2.  Use the `evaluateFunction` within the included `calc-standalone.scad` file to calculate the result of the expression.
3.  Output a 3D text object that displays the expression and its result (e.g., if `expression` is "1+1", then the text object would be "1+1=2").
4.  The text should be linearly extruded so that it is 3D and easily printable. Height of the extrusion can be a hardcoded value (say, 2mm).
5. Ensure you include `end_of_parameters_dummy()` at the end of the parameter definitions.

I don't think I need any fancy libraries like BOSL for this, just the standard OpenSCAD functionality plus the `calc-standalone.scad`. Thanks!

[Assistant]
calc-standalone.scad:
```
expression = "1+1";

module end_of_parameters_dummy() {}

//use <eval.scad>;
function _isString(v) = v >= "";
function _isVector(v) = !(v>="") && len(v) != undef;
function _isFloat(v) = v+0 != undef;

function _substr(s, start=0, stop=undef, soFar = "") =
    start >= (stop==undef ? len(s) : stop) ? soFar :
        _substr(s, start=start+1, stop=stop, soFar=str(soFar, s[start]));

function _parseInt(s, start=0, stop=undef, accumulated=0) =
    let( stop = stop==undef ? len(s) : stop )
        start >= stop ? accumulated :
        s[start] == "+" ? _parseInt(s, start=start+1, stop=stop) :
        s[start] == "-" ? -_parseInt(s, start=start+1, stop=stop) :
        let (digit = search(s[start], "0123456789"))
            digit == [] ? 0 : _parseInt(s, start=start+1, stop=stop, accumulated=accumulated*10+digit[0]);

function _findNonDigit(s, start=0) =
    start >= len(s) || s[start]<"0" || s[start]>"9" ? start :
    _findNonDigit(s, start=start+1);

function _parseUnsignedFloat(s) =
    len(s) == 0 ? 0 :
        let(
            firstNonDigit = _findNonDigit(s),
            decimalPart = s[firstNonDigit]!="." ?
                [firstNonDigit,firstNonDigit] : [firstNonDigit+1, _findNonDigit(s, start=firstNonDigit+1)],
            intPart = _parseInt(s,start=0,stop=firstNonDigit),
            fractionPart = _parseInt(s,start=decimalPart[0],stop=decimalPart[1]),
            baseExp = s[decimalPart[1]]=="e" || s[decimalPart[1]]=="E" ? pow(10,_parseInt(s, start=decimalPart[1]+1)) : 1)
            (intPart+fractionPart*pow(10,-(decimalPart[1]-decimalPart[0])))*baseExp;

function _tail(v) = len(v)>=2 ? [for(i=[1:len(v)-1]) v[i]] : [];
function _isspace(c) = (" " == c || "\t" == c || "\r" == c || "\n" == c );
function _isdigit(c) = ("0" <= c && c <= "9" );
function _isalpha(c) = ("a" <= c && c <= "z") || ("A" <= c && c <= "Z");
function _isalpha_(c) = _isalpha(c)  || c=="_";
function _isalnum_(c) = _isalpha(c) || _isdigit(c) || c=="_";
function _flattenLists(ll) = [for(a=ll) for(b=a) b];

function _spaceSequence(s, start=0, count=0) =
    len(s)>start && _isspace(s[start]) ? _spaceSequence(s, start=start+1, count=count+1) : count;
function _digitSequence(s, start=0, count=0) =
    len(s)>start && _isdigit(s[start]) ? _digitSequence(s, start=start+1,count=count+1) : count;
function _alnum_Sequence(s, start=0, count=0) =
    len(s)>start && _isalnum_(s[start]) ? _alnum_Sequence(s, start=start+1,count=count+1) : count;
function _identifierSequence(s, start=0, count=0) =
    len(s)>start && _isalpha_(s[start]) ? _alnum_Sequence(s, start=start+1, count=count+1) : count;
function _signedDigitSequence(s, start=0) =
    len(s) <= start ? 0 :
        (s[start] == "+" || s[start] == "-" ) ? 1+_digitSequence(s,start=start+1) : _digitSequence(s,start=start);
function _realStartingWithDecimal(s, start=0) =
    len(s)>start && s[start] == "." ?
        let(next = start+1+_digitSequence(s, start=start+1))
        (s[next] == "e" || s[next] == "E" ?
            next-start+1+_signedDigitSequence(s, start=next+1) : next-start)
        : 0;
function _realContinuation(s, start=0) =
    len(s) <= start ? 0 :
        let(c1=_realStartingWithDecimal(s, start=start))
        c1 > 0 ? c1 :
        s[start] == "e" || s[start] == "E" ?
            1+_signedDigitSequence(s, start=start+1) : 0;
function _positiveRealSequence(s, start=0) =
    len(s) <= start ? 0 :
        let(c1 = _realStartingWithDecimal(s, start=start))
            c1 > 0 ? c1 :
        let(c2 = _digitSequence(s, start=start))
            c2 > 0 ? c2 + _realContinuation(s, start=start+c2) : 0;

_multiSymbolOperators = [ "<=", ">=", "==", "&&", "||" ]; // must be in order of decreasing length

function _multiSymbolOperatorSequence(s, start=0) =
    (s[start]=="<" && s[start+1]=="=") ||
    (s[start]==">" && s[start+1]=="=") ||
    (s[start]=="=" && s[start+1]=="=") ||
    (s[start]=="!" && s[start+1]=="=") ||
    (s[start]=="&" && s[start+1]=="&") ||
    (s[start]=="|" && s[start+1]=="|") ? 2 : 0;

function _tokenize(s, start=0) =
    start >= len(s) ? [] :
    let(c1=_spaceSequence(s, start=start)) c1>0 ?
        concat([" "], _tokenize(s, start=start+c1)) :
    let(c2=_identifierSequence(s, start=start)) c2>0 ?
        concat([_substr(s, start=start, stop=start+c2)], _tokenize(s, start=start+c2)) :
    let(c3=_positiveRealSequence(s, start=start)) c3>0 ?
        concat([_substr(s, start=start, stop=start+c3)], _tokenize(s, start=start+c3)) :
    let(c4=_multiSymbolOperatorSequence(s, start=start)) c4>0 ?
        concat([_substr(s, start=start, stop=start+c4)], _tokenize(s, start=start+c4)) :
        concat([s[start]], _tokenize(s, start=start+1));

function _endParens(list,start=0,openCount=0,stop=undef) =
    let(stop = stop==undef ? len(list) : stop)
    start >= stop ? (openCount?undef:stop) :
    list[start][0] == ")" ?
            (openCount==1 ? start+1 : _endParens(list,start+1,stop=stop, openCount=openCount-1)) :
    _endParens(list,start+1,stop=stop, openCount=
        list[start][0] == "(" ?
            openCount+1 : openCount);

function _indexInTable(string, table, column=0) =
    let (s=search([string], table, index_col_num=column))
        s[0] == [] ? -1 : s[0][0];

_NAME = 0;
_ARITY = 1;
_PREC = 2;
_ASSOC_DIR = 3;
_ARGUMENTS_FROM_VECTOR = 4;
_OPERATOR = 5;
_EXTRA_DATA = 6;

function _func(op) = [ op, 1, -1, 1, true, op ];

_operators = [
    [ "[", 1, -1, 1, true, "[" ],
    [ "pow", 1, -1, 1, true, "^" ],
    [ "cross", 1, -1, 1, true, "cross" ],
    _func("sqrt"),
    _func("cos"),
    _func("sin"),
    _func("tan"),
    _func("acos"),
    _func("asin"),
    _func("atan"),
    _func("COS"),
    _func("SIN"),
    _func("TAN"),
    _func("ACOS"),
    _func("ASIN"),
    _func("ATAN"),
    _func("abs"),
    _func("ceil"),
    _func("exp"),
    _func("floor"),
    _func("ln"),
    _func("log"),
    _func("round"),
    _func("sign"),
    _func("norm"),
    [ "atan2", 1, -1, 1, true, "atan2" ],
    [ "ATAN2", 1, -1, 1, true, "ATAN2" ],
    [ "max", 1, -1, 1, true, "max" ],
    [ "min", 1, -1, 1, true, "min" ],
    [ "concat", 1, -1, 1, true, "concat" ],
    [ "#", 2, 0, -1, false, "#" ],
    [ "^", 2, 0, -1, false, "^" ],
    [ "#-",1, 0.5, 0, true, "-" ],
    [ "#+",1, 0.5, 0, true, "+" ],
    [ "*", 2, 1, 1, false, "*" ],
    [ "/", 2, 1, 1, false, "/" ],
    [ "%", 2, 1, 1, false, "%" ],
    [ "+", 2, 2, 1, true, "+" ],
    [ "-", 2, 2, 1, true, "-" ],
    [ "!=", 2, 3, 1, true, "!=" ],
    [ "==", 2, 3, 1, true, "==" ],
    [ "<=", 2, 3, 1, true, "<=" ],
    [ ">=", 2, 3, 1, true, ">=" ],
    [ "<", 2, 3, 1, true, "<" ],
    [ ">", 2, 3, 1, true, ">" ],
    [ "!", 1, 4, 1, true, "!" ],
    [ "&&", 2, 5, 1, true, "&&" ],
    [ "||", 2, 5, 1, true, "||" ],
    [ "?", 2, 10, -1, true, "?" ],
    [ ":", 2, 10, -1, true, ":" ],
    [ "=", 2, 30, 1, true, "=" ], // for let()
    [ "let", 1, 25, 1, true, "let" ],
    [ ",", 2, 100, 1, true, "," ]
   ];

_binary_or_unary = [ ["-", "#-"], ["+", "#+"], ["#", "["] ];

// insert parentheses in some places to tweak the order of
// operations in those contexts
function _fixBrackets(pretok,start=0) =
    start >= len(pretok) ? [] :
    pretok[start] == "[" ?
        concat(["#", "("], _fixBrackets(pretok,start=start+1)) :
    pretok[start] == "]" ?
        concat([")"], _fixBrackets(pretok,start=start+1)) :
    pretok[start] == "?" ?
        concat([pretok[start],"("], _fixBrackets(pretok,start=start+1)) :
    pretok[start] == ":" ?
        concat([")",pretok[start]], _fixBrackets(pretok,start=start+1)) :
        concat(pretok[start], _fixBrackets(pretok,start=start+1));

// disambiguate operators that can be unary or binary
function _fixUnaries(pretok) =
    [ for (i=[0:len(pretok)-1])
         let (
            a = pretok[i],
            j=_indexInTable(a, _binary_or_unary))
            (0 <= j && (i == 0 || pretok[i-1] == "(" ||
                0 <= _indexInTable(pretok[i-1], _operators)))? _binary_or_unary[j][1] : a ];

function _fixLet1(tok, start=0, stop=undef) =
    let (stop = stop==undef ? len(tok) : stop)
        start >= stop ? [] :
        tok[start][0] == "let"?
           let(endP=_endParens(tok,start=start+1,stop=stop,openCount=0)) concat([concat(tok[start], [_fixLet1(tok,start=start+2,stop=endP-1)])], _fixLet1(tok,start=endP,stop=stop)) :
        concat([tok[start]], _fixLet1(tok,start=start+1,stop=stop));

function _parsePass1(s) =
    let (pretok=_fixUnaries(_fixBrackets(_tokenize(s))))
    _fixLet1(
    [ for (i=[0:len(pretok)-1])
        let (a=pretok[i])
        if (a[0] != " ")
            let (j=_indexInTable(a, _operators))
                j >= 0 ? _operators[j] : [a] ] );

function _prec(op1, pos1, op2, pos2) =
    op1 != undef && op2 == undef ? false :
    op1 == undef && op2 != undef ? true :
    op1 == undef && op2 == undef ? true :
    op1[_ARITY] == 1 && pos1 > pos2 ? true :
    op2[_ARITY] == 1 && pos2 > pos1 ? false :
    op1[_PREC] < op2[_PREC] ? true :
        op2[_PREC] < op1[_PREC] ? false :
            op1[_ASSOC_DIR] * pos1 < op2[_ASSOC_DIR] * pos2;

function _parseLiteralOrVariable(s) =
        s == "PI" ? PI :
        s == "true" ? true :
        s == "false" ? false :
        s == "undef" ? undef :
        _isalpha_(s[0]) ? s :
        _parseUnsignedFloat(s);

function _isoperator(token) = _PREC<len(token);

function _getCandidatesForMainOperator(tok,start,stop) =
   start >= stop ? [] :
   tok[start][0] == "(" ?
        _getCandidatesForMainOperator(tok,_endParens(tok,start=start+1,stop=stop,openCount=1),stop)
        :
        _isoperator(tok[start]) ? concat([[tok[start],start]],_getCandidatesForMainOperator(tok,start+1,stop)) :
        _getCandidatesForMainOperator(tok,start+1,stop);

// Find the operator with least precedence
function _findMainOperatorPos(candidates,start=0) =
    len(candidates) <= start ? undef :
    let(rest=_findMainOperatorPos(candidates,start+1))
    _prec(candidates[rest][0], rest, candidates[start][0], start) ? start : rest;

function _firstOccurrence(c,opName,start=0) =
    start >= len(c) ? undef :
    c[start][0][0] == opName ? c[start] :
        _firstOccurrence(c,opName,start=start+1);

// We know the main operator is a ? or a :. We now need to find out which.
function _mainQuestionOperator(c) =
    let(fq = _firstOccurrence(c,"?"),
        fc = _firstOccurrence(c,":"))
        fq[1] != undef && (fc[1] == undef || fq[1] < fc[1]) ? fq : fc;

function _mainOperator(tok,start,stop) =
    let(c=_getCandidatesForMainOperator(tok,start,stop),
        pos=_findMainOperatorPos(c),
        m=c[pos])
        m[0][0] == "?" ?
            concat(m, [_firstOccurrence(c,":",start=pos+1)[1]])
            : m;

function _doLets(assignments, final, start=0) =
    start >= len(assignments) ? final :
    assignments[start][0] == "=" ? ["let", ["'", assignments[start][1]], assignments[start][2], _doLets(assignments, final, start=start+1)] : _doLets(assignments, final, start=start+1);

function _letOperator(a,b) =
    let(rawAssignments=_fixCommas(a),
        assignments=rawAssignments[0] == "[[" ?
            _tail(rawAssignments) : [a])
    _doLets(assignments, b);

/* This takes a fully tokenized vector, each element of which is either a line from the _operators table or a vector containing a single non-operator string, and parses it using general parenthesis and operator parsing. Comma expressions for building vectors will be parsed in the next pass. */
function _parseMain(tok,start=0,stop=undef) =
    let( stop= stop==undef ? len(tok) : stop )
        stop <= start ? undef :
        tok[start][0] == "(" && _endParens(tok,start=start+1,stop=stop,openCount=1)==stop ?
            _parseMain(tok,start=start+1,stop=stop-1) :
        let( lp = _mainOperator(tok,start,stop) )
            lp[0] == undef ? ( stop-start>1 ? undef : _parseLiteralOrVariable(tok[start][0]) ) :
            let( op = lp[0], pos = lp[1] )
                op[_NAME] == "?" ?
                    [ op[_OPERATOR], _parseMain(tok,start=start,stop=pos), _parseMain(tok,start=pos+1,stop=lp[2]), _parseMain(tok,start=lp[2]+1,stop=stop) ] :
                op[_NAME] == "let" ?
                    _letOperator( _parseMain(op[_EXTRA_DATA]), _parseMain(tok,start=pos+1,stop=stop)) :
                op[_ARITY] == 2 ?
                    [ op[_OPERATOR], _parseMain(tok,start=start,stop=pos), _parseMain(tok,start=pos+1,stop=stop) ]
                    : [ op[_OPERATOR], _parseMain(tok,start=pos+1,stop=stop) ];

// this upgrades sequences of binary commas to vectors
function _fixCommas(expression) =
    expression[0] == "," ?
        let(a=_fixCommas(expression[1]),
            b=_fixCommas(expression[2]))
            a[0] == "[[" ?
                concat(["[["],concat(_tail(a), [b])) :
                ["[[",a,b]
        :
    _isVector(expression) ?
            concat([expression[0]], [for (i=[1:len(expression)-1]) _fixCommas(expression[i])]) :
            expression;

// fix arguments from vectors
function _fixArguments(expression) =
    let(i=_indexInTable(expression[0], _operators, _OPERATOR))
            i >=0 && _operators[i][_ARGUMENTS_FROM_VECTOR] && expression[1][0] == "[[" ? concat([expression[0]], [for (i=[1:len(expression[1])-1]) _fixArguments(expression[1][i])]) :
/*            expression[0] == "?" ?
                concat([expression[0],expression[1]],[for (i=[1:len(expression[2])-1]) _fixArguments(expression[2][i])]) : */
            len(expression)>1 && !_isString(expression) ?
                concat([expression[0]], [for (i=[1:len(expression)-1]) _fixArguments(expression[i])])
                    : expression;

function _optimizedLiteral(x) =
    len(x)==undef ? x : ["'", x];

function _wellDefined(x) =
    x==undef ? false :
    len(x)==undef ? true :
    x[0] == "'" ? true :
    len(x)==1 ? x[0]!=undef :
    len([for (a=x) if(!_wellDefined(a)) true])==0;

function _optimize(expression) =
    let(x=eval(expression,$careful=true))
        _wellDefined(x) ? _optimizedLiteral(x) :
        expression[0] == "'" ? _optimizedLiteral(x) :
        ! _isString(expression) ?
            concat([expression[0]], [for(i=[1:len(expression)-1]) _optimize(expression[i])]) :
        expression;

function compileFunction(expression,optimize=true) =
            _isVector(expression) ? expression :
            _isFloat(expression) ? expression :
            let(unoptimized = _fixArguments(_fixCommas(_parseMain(_parsePass1(expression)))))
        optimize ? _optimize(unoptimized) : unoptimized;

function evaluateFunction(expression,variables) = eval(compileFunction(expression,optimize=false),variables);

function _let(v, var, value) = concat([var, value], v);

function _lookupVariable(var, table) =
    let (s=search([var], table, index_col_num=0))
        s[0] == [] ? undef : table[s[0][0]][1];

function _generate(var, range, expr, v) =
    [ for(i=range) eval(expr, _let(v, var, i)) ];

function _safeNorm(v) =
    ! _isVector(v) || len([for (x=v) x+0==undef]) ? undef : norm(v);

function eval(c,v=[]) =
    ""<=c ? _lookupVariable(c,v) :
    let(op=c[0]) (
    op == undef ? c :
    op == "'" ? c[1] :
    op == "+" ? (len(c)==2 ? eval(c[1],v) : eval(c[1],v)+eval(c[2],v)) :
    op == "-" ? (len(c)==2 ? -eval(c[1],v) : eval(c[1],v)-eval(c[2],v)) :
    op == "*" ? eval(c[1],v)*eval(c[2],v) :
    op == "/" ? eval(c[1],v)/eval(c[2],v) :
    op == "%" ? eval(c[1],v)%eval(c[2],v) :
    op == "sqrt" ? sqrt(eval(c[1],v)) :
    op == "^" || op == "pow" ? pow(eval(c[1],v),eval(c[2],v)) :
    op == "cos" ? cos(eval(c[1],v)) :
    op == "sin" ? sin(eval(c[1],v)) :
    op == "tan" ? tan(eval(c[1],v)) :
    op == "acos" ? acos(eval(c[1],v)) :
    op == "asin" ? asin(eval(c[1],v)) :
    op == "atan" ? atan(eval(c[1],v)) :
    op == "atan2" ? atan2(eval(c[1],v),eval(c[2],v)) :
    op == "COS" ? cos(eval(c[1],v)*180/PI) :
    op == "SIN" ? sin(eval(c[1],v)*180/PI) :
    op == "TAN" ? tan(eval(c[1],v)*180/PI) :
    op == "ACOS" ? acos(eval(c[1],v))*PI/180 :
    op == "ASIN" ? asin(eval(c[1],v))*PI/180 :
    op == "ATAN" ? atan(eval(c[1],v))*PI/180 :
    op == "ATAN2" ? atan2(eval(c[1],v),eval(c[2],v))*PI/180 :
    op == "abs" ? abs(eval(c[1],v)) :
    op == "ceil" ? ceil(eval(c[1],v)) :
    op == "cross" ? cross(eval(c[1],v),eval(c[2],v)) :
    op == "exp" ? exp(eval(c[1],v)) :
    op == "floor" ? floor(eval(c[1],v)) :
    op == "ln" ? ln(eval(c[1],v)) :
    op == "len" ? len(eval(c[1],v)) :
    op == "log" ? log(eval(c[1],v)) :
    op == "max" ? (len(c) == 2 ? max(eval(c[1],v)) : max([for(i=[1:len(c)-1]) eval(c[i],v)])) :
    op == "min" ? (len(c) == 2 ? min(eval(c[1],v)) : min([for(i=[1:len(c)-1]) eval(c[i],v)])) :
    op == "norm" ?
        (!$careful ? norm(eval(c[1],v)) : _safeNorm(eval(c[1],v))) :
    op == "rands" ? rands(eval(c[1],v),eval(c[2],v),eval(c[3],v),eval(c[4],v)) :
    op == "round" ? round(eval(c[1],v)) :
    op == "sign" ? sign(eval(c[1],v)) :
    op == "[" ? [for (i=[1:len(c)-1]) eval(c[i],v)] :
    op == "#" ? eval(c[1],v)[eval(c[2],v)] :
    op == "<" ? eval(c[1],v)<eval(c[2],v) :
    op == "<=" ? eval(c[1],v)<=eval(c[2],v) :
    op == ">=" ? eval(c[1],v)>=eval(c[2],v) :
    op == ">" ? eval(c[1],v)>=eval(c[2],v) :
    op == "==" ? (!$careful ? eval(c[1],v)==eval(c[2],v) :
        (let(c1=eval(c[1],v))
        c1==undef ? undef :
        let(c2=eval(c[2],v))
        c2==undef ? undef :
        c1 == c2) ) :
    op == "!=" ? (!$careful ? eval(c[1],v)!=eval(c[2],v) :
        (let(c1=eval(c[1],v))
        c1==undef ? undef :
        let(c2=eval(c[2],v))
        c2==undef ? undef :
        c1 != c2) ) :
    op == "&&" ? (!$careful ? eval(c[1],v)&&eval(c[2],v) :
        (let(c1=eval(c[1],v))
        c1==undef ? undef :
        !c1 ? false :
        let(c2=eval(c[2],v))
        c2==undef ? undef :
        c1 && c2) ) :
    op == "||" ? (!$careful ? eval(c[1],v)||eval(c[2],v) :
        (let(c1=eval(c[1],v))
        c1==undef ? undef :
        c1 ? true :
        let(c2=eval(c[2],v))
        c2==undef ? undef :
        c1 || c2) ) :
    op == "!" ? (!$careful ? !eval(c[1],v) :
        (let(c1=eval(c[1],v))
        c1==undef ? undef :
        !c1) ) :
    op == "?" ? (!$careful ? (eval(c[1],v)?eval(c[2],v):eval(c[3],v)) :
        (let(c1=eval(c[1],v))
        c1==undef ? undef :
        c1 ? eval(c[2],v):eval(c[3],v)) ):

    op == "concat" ? [for (i=[1:len(c)-1]) let(vect=eval(c[i],v)) for(j=[0:len(vect)-1]) vect[j]] :
    op == "range" ? (len(c)==3 ? [eval(c[1],v):eval(c[2],v)] : [eval(c[1],v):eval(c[2],v):eval(c[3],v)]) :
    op == "let" ? (!$careful ? eval(c[3],concat([[eval(c[1],v),eval(c[2],v)]], v)) :
            let(c1=eval(c[1],v),c2=eval(c[2],v))
                c1==undef || c2==undef ? undef :
                    eval(c[3],concat([[c1,c2]], v)) ) :
    op == "gen" ? _generate(eval(c[1],v),eval(c[2],v),c[3],v) :
    undef
    );

// per 10,000 operations with "x^3*y-x*y^3"
// 24 sec compile
// 21 sec unoptimized compile
// 22 sec evaluateFunction()
// 0.7 sec eval

// pass1 10 seconds [tokenize: 4 seconds]
// parseMain 6
// fixCommas 0
// fixArguments 3
// optimize 3
/*
echo(compileFunction("x^(2*3)"));
fc = compileFunction("x^3*y-x*y^3",optimize=true);
echo(fc);
echo(eval(fc,[["x",1],["y",1]]));
z=[for(i=[0:9999]) compileFunction("x^3*y-x*y^3",optimize=false)];//fc,[ ["x",1],["y",2] ])];
*/

//z = [for(i=[1:10000]) compileFunction("x^3*y-x*y^3")];
// normal: 23

//function repeat(s, copies, soFar="") = copies <= 0 ? soFar : repeat(s, copies-1, soFar=str(soFar,s));

linear_extrude(height=2)
text(str(expression,"=",evaluateFunction(expression)));

```


[User]
Hi! I'm looking for an OpenSCAD design for a customizable filament spool holder. I'd like it to be parametric, so I can easily adjust it to fit different spools and mounting setups. I've got some ideas for different hub designs, but need help implementing it in SCAD.

Here's what I'm thinking:

**General Spool Dimensions:**

*   **`spool_diameter`**: The inner diameter of the filament spool (the hole size). I'd like to be able to adjust this, probably between 20 and 100 mm, in increments of 0.5 mm.
*   **`spool_width`**: The external width of the filament spool. Adjustable from 30 to 100 mm, in 1 mm increments.
*   **`shaft_diameter`**: The diameter of the threaded shaft that the spool will mount onto. Adjustable from 3 to 20 mm, in 0.5 mm increments.

**Hub Settings:**

*   **`hub_length`**: The length of the center hub of the spool. Adjustable from 20 to 120 mm, in 0.5 mm increments. This is useful to offset the spool on the shaft if the shaft is shorter than the spool width.
*   **`hub_diameter`**: The diameter of the center hub itself. This needs to be bigger than the shaft diameter. Adjustable from 10 to 30 mm, in 0.5 mm increments.

**General Settings:**

*   **`wall_thickness`**: The thickness of the body walls of the spool holder. I'd like this to be adjustable from 0 to 6 mm, in 0.5 mm increments.
*   **`collar_diameter`**: The diameter of the rear collar that supports the spool, should be larger than the spool diameter. Adjustable from 30 to 150 mm in 1 mm increments
*   **`collar_thickness`**: The thickness of the rear collar. Adjustable from 0 to 10 mm, in 0.5 mm increments.
*  **`edge_curve`**: Amount of Minkowski transform for rounding edges.  I need this to be less than half of the wall thickness. Adjustable from 0 to 1.9, in 0.1 increments.

**Spoke Settings:**

*   **`spoke_type`**: This will control the type of spokes used. I'm thinking of four options, and I'd like to be able to switch easily between them:
    *   `"blade"`: Standard straight blades that connect the hub to the outer rim.
    *   `"wire"`: Wire-like spokes like on a bicycle wheel.
    *   `"spiral"`: A Fibonacci Golden Spiral design.
    *   `"auger"`: A corkscrew-like center.
*   **`spoke_count`**: The number of blades or spokes used. Adjustable from 1 to 30, in increments of 1.
*   **`spoke_thickness`**: The thickness of each blade or spoke, adjustable from 1 to 10 mm in 0.5 mm increments.
*   **`spoke_rotation`**: The angle of each blade or spoke. Adjustable from 0 to 25 degrees, in increments of 5.

For the `auger` option I would like to use the `auger` function from the `MCAD` library.

It would be great if the design also included an option to leave a small gap at the base of the spiral design for the "spiral" spoke type, so that the individual spirals are allowed to flex.

I'd like to see the generated code, but I don't need you to create anything.

Thanks!

[Assistant]
Customisable_Spool_Holder_v1.2.scad:
```
// A fully parameterised Filament Spool holder
//   Author: Nick Wells
// Revision: 1.0 19/01/2018 Initial release
//           1.1 20/03/2018 Added bq spool sunken profile
//           1.2 03/02/2019 Refactored Code
// http://customizer.makerbot.com/docs
// Credit to https://openhome.cc/eGossip/OpenSCAD/GoldenSpiral.html
// for the Golden Spiral

// Set the spool and shaft sizes here. all units in mm
/* [Spool Settings] */
// Internal diameter of filament spool (mm)
spool_diameter = 57; // [20:0.5:100]

// External width of the Filament spool (mm)
spool_width    = 70;  // [30:1:100]

// Threaded shaft diameter
shaft_diameter = 7; // [3:0.5:20]

/* [Hub Settings]*/
// Centre hub length
hub_length     = 70; // [20:0.5:120]

// Centre hub diameter
hub_diameter   = 15; // [10:0.5:30]

/*[ General Settings ]*/
// Thickness of body walls
wall_thickness = 0;  //  [0:0.5:6]

// Rear Coller diameter
collar_diameter = 80; // [30:1:150]

// Rear Collar thickness
collar_thickness   = 2;  // [0:0.5:10]

// Minkowski curved edges must be less than half of the wall thickness
edge_curve     = 0; //[0:0.1:1.9]

/* [Spoke Settings ]*/
// Type of spool hub
spoke_type      = "spiral"; // [blade,wire,spiral,auger]

// Number of blades or spokes
spoke_count     = 10; // [1:1:30]

// Thickness of blade or spokes
spoke_thickness = 1.5; // [1:0.5:10]

// Angle of blade or spoke
spoke_rotation  = 0; // [0,5,25]

// Now the fun bit!
// You can makes some cool spools by altering the spoke settings

// brand    type   diam   depth  spokes thickness rotation
// eSun     blade  52     70     3      4         30
// Sunlu    blade  72     70     3      4         30
// bq       blade  45     65     8      2         30
// bq       spiral 45     65     10     1.5       0
// priline  spiral 57     68     10     1.5       0

// Here are some samples,
// ############################################################################################
// ## Type 1) A standard hub, to use this set the spoke_type to "blade"                      ##
// ############################################################################################
// Then set the 3 spoke parameters using one of the samples below and press F6 to render:
// A single spoke hub       1,5,0
// A standard 5 spoke hub   5,5,0
// A thin 6 spoke hub       6,3,0
// A slanted  3 spoke hub   3,4,20
// A 10 blade fan           10,2,10
// A 20 blade turbine fan   20,1,20

// ############################################################################################
// ## Type 2) This is an interesting hub using an auger, to use it set spoke_type to "auger" ##
// ############################################################################################
// This ignores all other spoke settings
// Pretty cool but needs support to print

// ############################################################################################
// ## Type 3) This one makes a Jaguar style spoked hub, to use it set spoke_type to "wire"   ##
// ############################################################################################
// The spoke_count and spoke_thickness can be used
// Pretty but will be interesting to print!
// A 12 thick spoke hub 6,5,0
// A 24 thin spoke hub  12,3,0

// Some of the options will take a while to render due to the Minkowski curved edges.

/* [hidden] */
$fn=100;

// Uses the MCAD library to create the auger
include <MCAD/screw.scad>

// Create the spool!
MainSpool();

module MainSpool()
{
  translate([0,0,edge_curve])
  {
    difference()
    {
      spool_body();
      spool_remove();
    }
  }
}

module spool_body()
{
   shell();
   hub();
   spokes();
}

module spool_remove()
{
  // Shaft hole
  translate([0,0,-0.5])cylinder(d=shaft_diameter,h=spool_width-2*edge_curve+1);

  // Trim for short shaft
  translate([0,0,hub_length])cylinder(d=spool_diameter-2*wall_thickness,h=spool_width-hub_length+1);
}

module shell()
{
  difference()
  {
     minkowski()
     {
       shell_body();
       sphere(edge_curve);
     }
     shell_remove();
  }
}
module shell_body()
{
    // Back collar
    cylinder(d=collar_diameter-2*edge_curve,h=collar_thickness-2*edge_curve);
    // spool hub
    cylinder(d=spool_diameter-2*edge_curve,h=spool_width-2*edge_curve);
}
module shell_remove()
{
  // Add a bit so the hole renders ok in OpenSCAD
  translate([0,0,-0.5])cylinder(d=spool_diameter-2*wall_thickness,h=spool_width+1);
}

module hub()
{
  // Hub
  cylinder(d=hub_diameter,h=spool_width-2*edge_curve);
}

module spokes()
{
  difference()
  {
    spoke();
    spoke_trim();
  }
}
module spoke()
{
  if(spoke_type == "auger")  auger_spoke();
  if(spoke_type == "wire")   translate([0,0,hub_diameter])wire_spoke();
  if(spoke_type == "blade")  translate([0,0,-spoke_thickness/2])blade_spoke();
  if(spoke_type == "spiral") spiral_spoke();
}
module spoke_trim()
{
  // trim top
  translate([0,0,spool_width-0.01])cylinder(d=spool_diameter*2,h=collar_thickness+hub_diameter);

  // trim bottom
  translate([0,0,-spoke_thickness])cylinder(d=collar_diameter,h=spoke_thickness);

  // Leave a gap at the base of the spiral to detach it from the collar
  if(spoke_type == "spiral")
  {
     translate([0,0,collar_thickness])cylinder(d=collar_diameter,h=collar_thickness);
     difference()
     {
       cylinder(d=spool_diameter*2,h=spool_width);
       cylinder(d=spool_diameter+2,h=spool_width);
     }
  }
  else
  {
    // trim shell
    difference()
    {
      cylinder(d=spool_diameter*2,h=spool_width);
      cylinder(d=spool_diameter,h=spool_width);
    }
  }
}
module auger_spoke()
{
      // Uses the auger function from the MCAD library supplied with OpenSCAD
    // auger(pitch, length, outside_radius, inner_radius, taper_ratio = 0.25)
    auger(30,spool_width,spool_diameter/2-wall_thickness,hub_diameter/2,0.25);
}
module wire_spoke()
{
  // Generate spokes
    for(a = [0:360/spoke_count:360])
    {
      rotate([0,0,a])translate([0,spool_diameter/4+spoke_thickness/2,0])rotate([45,0,0])
        cylinder(d=spoke_thickness, h = spool_diameter/2+2*wall_thickness+10,center=true);

      rotate([0,0,a+(180/spoke_count)])translate([0,spool_diameter/4+spoke_thickness/2,0])rotate([-45,0,0])
        cylinder(d=spoke_thickness, h = spool_diameter/2+2*wall_thickness+10,center=true);
    }
}

module blade_spoke()
{
  for(a = [0:360/spoke_count:360])
  {
    rotate([spoke_rotation,0,a])
      translate([-spool_diameter/2,0,0])
        cube([spool_diameter/2,spoke_thickness,spool_width+hub_diameter]);
  }
}

module spiral_spoke()
{
  cylinder(h=collar_thickness,d=spool_diameter);

  // from, to thickness
  translate([0,0,collar_thickness+0.2])
  {
    linear_extrude(height=hub_length)
    for(a = [0:360/spoke_count:360])
    {
    rotate([0,0,a])golden_spiral(5, 9, spoke_thickness);
    }
  }
}

// Credit to https://openhome.cc/eGossip/OpenSCAD/GoldenSpiral.html
function fibonacci(nth) =
    nth == 0 || nth == 1 ? nth : (
        fibonacci(nth - 1) + fibonacci(nth - 2)
    );

module sector(radius, angles, fn = 24) {
    r = radius / cos(180 / fn);
    step = -360 / fn;

    points = concat([[0, 0]],
        [for(a = [angles[0] : step : angles[1] - 360])
            [r * cos(a), r * sin(a)]
        ],
        [[r * cos(angles[1]), r * sin(angles[1])]]
    );

    difference() {
        circle(radius, $fn = fn);
        polygon(points);
    }
}

module arc(radius, angles, width = 1, fn = 24) {
    difference() {
        sector(radius + width, angles, fn);
        sector(radius, angles, fn);
    }
}

module golden_spiral(from, to, thickness) {
    if(from <= to) {
        f1 = fibonacci(from);
        f2 = fibonacci(from + 1);

        arc(f1, [0, 90], thickness, 100);

        offset = f2 - f1;

        translate([0, -offset, 0]) rotate(90)
            golden_spiral(from + 1, to, thickness);
    }
}
```


[User]
Hey, I'm looking to design a snowflake-shaped doorstop in OpenSCAD, and I really like the design in the provided code, but I'd like to be able to customize it more easily with parameters. I want to be able to specify the number of arms, the overall diameter, the thickness of the main body, and the thickness of the circular base that gives the doorstop it's stability.

The basic structure is a central cylinder, and then these arm shapes are arrayed radially around it. Each arm has three 'branches' - one straight branch pointing directly out, and two at angles off that main straight branch. These are made by using several cylinders and hull to create those rounded branch shapes. The base is made by having a wider cylinder at the base that goes a little higher than the bottom of the main body of the doorstop, and a chamfered cylinder on the bottom.

So, could you create a parametric OpenSCAD file that can generate this design? I'd need to be able to set the number of arms, the total diameter, the thickness, and the base thickness as parameters, just like in the description. I would also like to specify the thickness of the cylindrical branches that make up the arms. Additionally, could I control the length of those cylindrical branch segments? Let's also make the radius of the main cylinder a parameter. Finally, can we set the amount the central cylinder extends past the bottom edge of the arms? That should cover it. Thanks a lot!

[Assistant]
snowflake_doorstop.scad:
```
//!OpenSCAD

arms = 6; //[2:1:7]
diameter = 150;
thickness = 15;
outside_thickness = 2;

intersection() {
scale([(diameter / 136), (diameter / 136), 1]){
difference() {
for (j = [1 : abs(1) : arms]) {
rotate([0, 0, (j * (360 / arms))]){
// chain hull
for (i = [0 : abs(50) : 50 - 50]) {
hull() {
translate([0, (10.5 + i), 0]){
cylinder(r1=8, r2=8, h=thickness, center=false);
}
translate([0, (10.5 + (i + 50)), 0]){
cylinder(r1=8, r2=8, h=thickness, center=false);
}
}  // end hull (in loop)
} // end loop

// chain hull
for (i = [0 : abs(20) : 20 - 20]) {
hull() {
translate([i, (35 + i), 0]){
cylinder(r1=8, r2=8, h=thickness, center=false);
}
translate([(i + 20), (35 + (i + 20)), 0]){
cylinder(r1=8, r2=8, h=thickness, center=false);
}
}  // end hull (in loop)
} // end loop

// chain hull
for (i = [0 : abs(20) : 20 - 20]) {
hull() {
translate([(i * -1), (35 + i), 0]){
cylinder(r1=8, r2=8, h=thickness, center=false);
}
translate([((i + 20) * -1), (35 + (i + 20)), 0]){
cylinder(r1=8, r2=8, h=thickness, center=false);
}
}  // end hull (in loop)
} // end loop

}
}

for (j = [1 : abs(1) : arms]) {
rotate([0, 0, (j * (360 / arms))]){
// chain hull
for (i = [0 : abs(50) : 50 - 50]) {
hull() {
translate([0, (10.5 + i), 0]){
cylinder(r1=3, r2=3, h=thickness, center=false);
}
translate([0, (10.5 + (i + 50)), 0]){
cylinder(r1=3, r2=3, h=thickness, center=false);
}
}  // end hull (in loop)
} // end loop

// chain hull
for (i = [0 : abs(20) : 20 - 20]) {
hull() {
translate([i, (35 + i), 0]){
cylinder(r1=3, r2=3, h=thickness, center=false);
}
translate([(i + 20), (35 + (i + 20)), 0]){
cylinder(r1=3, r2=3, h=thickness, center=false);
}
}  // end hull (in loop)
} // end loop

// chain hull
for (i = [0 : abs(20) : 20 - 20]) {
hull() {
translate([(i * -1), (35 + i), 0]){
cylinder(r1=3, r2=3, h=thickness, center=false);
}
translate([((i + 20) * -1), (35 + (i + 20)), 0]){
cylinder(r1=3, r2=3, h=thickness, center=false);
}
}  // end hull (in loop)
} // end loop

}
}

cylinder(r1=11, r2=11, h=thickness, center=false);
}
difference() {
cylinder(r1=16, r2=16, h=thickness, center=false);

cylinder(r1=11, r2=11, h=thickness, center=false);
}
}

scale([(diameter / 50), (diameter / 50), 1]){
union(){
translate([0, 0, outside_thickness]){
cylinder(r1=26, r2=5.9, h=(thickness - outside_thickness), center=false);
}
cylinder(r1=26, r2=26, h=outside_thickness, center=false);
}
}

}

```


[User]
I'd like to create a customizable origami moose, similar to the one I saw on Thingiverse. I need a parametric OpenSCAD file that lets me control the overall size, the height, and the thickness of both the outer and inner outlines. It should also allow for rounded corners on the inner outlines, and an option to flip the model horizontally. The inner and outer outline thicknesses need to be separately adjustable.

The moose design is defined by a series of points and polygons. I'll provide the coordinates for the outer points and inner polygons, and the code should be able to handle scaling and placement based on the max size parameter. Also, it would be nice if the scaling kept the aspect ratio correct, so the moose isn't distorted.

Here are the point coordinates defining the outer shape, which I'll call 'outline':

```
A1 = [191, 989];
A2 = [158, 901];
A3 = [159, 841];
A4 = [357, 586];
A5 = [379, 561];
A6 = [276, 491];
A7 = [203, 413];
A8 = [164, 296];
A9 = [226, 395];
A10 = [300, 467];
A11 = [411, 523];
A12 = [461, 464];
A13 = [480, 466];
A14 = [478, 414];
A15 = [406, 292];
A16 = [393, 192];
A17 = [420, 288];
A18 = [496, 395];
A19 = [537, 410];
A20 = [571, 364];
A21 = [581, 276];
A22 = [550, 208];
A23 = [547, 144];
A24 = [566, 211];
A25 = [604, 265];
A26 = [612, 304];
A27 = [636, 300];
A28 = [682, 244];
A29 = [691, 221];
A30 = [677, 67];
A31 = [710, 159];
A32 = [712, 203];
A33 = [747, 217];
A34 = [774, 210];
A35 = [792, 178];
A36 = [801, 200];
A37 = [822, 160];
A38 = [834, 181];
A39 = [866, 143];
A40 = [885, 96];
A41 = [886, 56];
A42 = [903, 101];
A43 = [879, 170];
A44 = [828, 248];
A45 = [724, 357];
A46 = [654, 437];
A47 = [1086, 348];
A48 = [1427, 462];
A49 = [1982, 442];
A50 = [2219, 591];
A51 = [2269, 647];
A52 = [2292, 751];
A53 = [2271, 817];
A54 = [2255, 808];
A55 = [2241, 754];
A56 = [2248, 830];
A57 = [2151, 1037];
A58 = [2208, 1376];
A59 = [2104, 1787];
A60 = [2073, 1795];
A61 = [2048, 1779];
A62 = [2076, 1422];
A63 = [1842, 1058];
A64 = [1570, 1118];
A65 = [1132, 1105];
A66 = [1093, 1779];
A67 = [1065, 1795];
A68 = [1042, 1779];
A69 = [1027, 1471];
A70 = [941, 1080];
A71 = [764, 890];
A72 = [640, 904];
A73 = [555, 1044];
A74 = [514, 1055];
A75 = [467, 938];
A76 = [413, 918];
A77 = [357, 922];
A78 = [288, 995];
A79 = [249, 993];
```
And here are the inner polygon definitions, using the 'A' points and also 'B' points:
```
B1 = [343, 891];
B2 = [518, 770];
B3 = [545, 803];
B4 = [580, 735];
B5 = [568, 680];
B6 = [481, 508];
B7 = [410, 579];
B8 = [494, 566];
B9 = [604, 497];
B10 = [815, 794];
B11 = [1084, 948];
B12 = [1627, 909];
B13 = [1783, 874];
B14 = [2125, 1413];

C1 = [A11, A12, A13, B6];
C2 = [A8, A9, A10, A11, B6, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, B9, B8, B7, A6, A7];
C3 = [A46, B5, A4, A5, B7, B8, B9];
C4 = [A4, A3, A2, B1, B2, B5];
C5 = [A2, A1, A79, B1];
C6 = [A79, B1, A77, A78];
C7 = [B1, B2, B5, B4, B3, A77];
C8 = [A77, B3, B4, B10, A70, A71, A72, A73, A74, A75, A76];
C9 = [B4, B5, A46, A47, B10];
C10 = [A47, B11, A67, A68, A69, A70, B10];
C11 = [B11, A65, A66, A67];
C12 = [B11, B12, B13, A63, A64, A65];
C13 = [B11, A47, A48, B13, B12];
C16 = [A48, A49, B13];
C17 = [A49, A50, A55, A56, A57, A58, A59, A60, B14, B13];
C18 = [A50, A51, A52, A53, A54, A55];
C19 = [B13, B14, A60, A61, A62, A63];

```

I'd like to be able to set the max dimension, model height, outer outline thickness, inner outline thickness and inner outline edge radius. It'd be great to have the ability to flip the model along the y axis, too. I think that should cover it.

[Assistant]
customizable_origami_moose.scad:
```
/*
 * Customizable Origami - Moose - https://www.thingiverse.com/thing:2762595
 * by Dennis Hofmann - https://www.thingiverse.com/mightynozzle/about
 * created 2018-01-19
 * version v1.0
 *
 * Changelog
 * --------------
 * v1.0:
 *      - final design
 * --------------
 *
 * This work is licensed under the Creative Commons - Attribution - NonCommercial - ShareAlike license.
 * https://creativecommons.org/licenses/by-nc-sa/3.0/
 */

 // Parameter Section //
//-------------------//

// preview[view:north, tilt:top]

// The maximum size of the longest side. The shorter side will be automatically resized in same ratio.
max_size_in_millimeter = 120; //[20:300]

// The height of the model.
model_height_in_millimeter = 5; //[0.2:0.2:100]

// Thickness of the outer outline.
outline_size_in_millimeter = 1.6; //[0.5:0.1:20]

// Thickness of the inner outline.
inline_size_in_millimeter = 0.8; //[0.5:0.1:20]

// Roundiness of the ends of the inner outlines.
inline_edge_radius_in_millimeter = 1.3; //[0.0:0.1:5]

// Flip model
flip_model = "no"; //[yes,no]

/*[hidden]*/
max_size = max_size_in_millimeter;
model_height = model_height_in_millimeter;
$fn=32;

// Outer Points
A1 = [191, 989];
A2 = [158, 901];
A3 = [159, 841];
A4 = [357, 586];
A5 = [379, 561];
A6 = [276, 491];
A7 = [203, 413];
A8 = [164, 296];
A9 = [226, 395];
A10 = [300, 467];
A11 = [411, 523];
A12 = [461, 464];
A13 = [480, 466];
A14 = [478, 414];
A15 = [406, 292];
A16 = [393, 192];
A17 = [420, 288];
A18 = [496, 395];
A19 = [537, 410];
A20 = [571, 364];
A21 = [581, 276];
A22 = [550, 208];
A23 = [547, 144];
A24 = [566, 211];
A25 = [604, 265];
A26 = [612, 304];
A27 = [636, 300];
A28 = [682, 244];
A29 = [691, 221];
A30 = [677, 67];
A31 = [710, 159];
A32 = [712, 203];
A33 = [747, 217];
A34 = [774, 210];
A35 = [792, 178];
A36 = [801, 200];
A37 = [822, 160];
A38 = [834, 181];
A39 = [866, 143];
A40 = [885, 96];
A41 = [886, 56];
A42 = [903, 101];
A43 = [879, 170];
A44 = [828, 248];
A45 = [724, 357];
A46 = [654, 437];
A47 = [1086, 348];
A48 = [1427, 462];
A49 = [1982, 442];
A50 = [2219, 591];
A51 = [2269, 647];
A52 = [2292, 751];
A53 = [2271, 817];
A54 = [2255, 808];
A55 = [2241, 754];
A56 = [2248, 830];
A57 = [2151, 1037];
A58 = [2208, 1376];
A59 = [2104, 1787];
A60 = [2073, 1795];
A61 = [2048, 1779];
A62 = [2076, 1422];
A63 = [1842, 1058];
A64 = [1570, 1118];
A65 = [1132, 1105];
A66 = [1093, 1779];
A67 = [1065, 1795];
A68 = [1042, 1779];
A69 = [1027, 1471];
A70 = [941, 1080];
A71 = [764, 890];
A72 = [640, 904];
A73 = [555, 1044];
A74 = [514, 1055];
A75 = [467, 938];
A76 = [413, 918];
A77 = [357, 922];
A78 = [288, 995];
A79 = [249, 993];

outline = [A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, A47, A48, A49, A50, A51, A52, A53, A54, A55, A56, A57, A58, A59, A60, A61, A62, A63, A64, A65, A66, A67, A68, A69, A70, A71, A72, A73, A74, A75, A76, A77, A78, A79];

// Inner Points
B1 = [343, 891];
B2 = [518, 770];
B3 = [545, 803];
B4 = [580, 735];
B5 = [568, 680];
B6 = [481, 508];
B7 = [410, 579];
B8 = [494, 566];
B9 = [604, 497];
B10 = [815, 794];
B11 = [1084, 948];
B12 = [1627, 909];
B13 = [1783, 874];
B14 = [2125, 1413];

// Polygons
C1 = [A11, A12, A13, B6];
C2 = [A8, A9, A10, A11, B6, A13, A14, A15, A16, A17, A18, A19, A20, A21, A22, A23, A24, A25, A26, A27, A28, A29, A30, A31, A32, A33, A34, A35, A36, A37, A38, A39, A40, A41, A42, A43, A44, A45, A46, B9, B8, B7, A6, A7];
C3 = [A46, B5, A4, A5, B7, B8, B9];
C4 = [A4, A3, A2, B1, B2, B5];
C5 = [A2, A1, A79, B1];
C6 = [A79, B1, A77, A78];
C7 = [B1, B2, B5, B4, B3, A77];
C8 = [A77, B3, B4, B10, A70, A71, A72, A73, A74, A75, A76];
C9 = [B4, B5, A46, A47, B10];
C10 = [A47, B11, A67, A68, A69, A70, B10];
C11 = [B11, A65, A66, A67];
C12 = [B11, B12, B13, A63, A64, A65];
C13 = [B11, A47, A48, B13, B12];
C14 = [A48, B12, B11];
C15 = [A48, B13, B12];
C16 = [A48, A49, B13];
C17 = [A49, A50, A55, A56, A57, A58, A59, A60, B14, B13];
C18 = [A50, A51, A52, A53, A54, A55];
C19 = [B13, B14, A60, A61, A62, A63];

cut_polygons = [C1, C2, C3, C4, C5, C6, C7, C8, C9, C10, C11, C12, C13, /*C14, C15,*/ C16, C17, C18, C19];

min_x = A2[0];
min_y = A41[1];
max_x = A52[0];
max_y = A60[1];

x_size = max_x - min_x;
y_size = max_y - min_y;

x_factor = max_size / x_size;
y_factor = max_size / y_size;

inline_size = x_size > y_size ? inline_size_in_millimeter / x_factor / 2: inline_size_in_millimeter / y_factor / 2;
inline_edge_radius = x_size > y_size ? inline_edge_radius_in_millimeter / x_factor: inline_edge_radius_in_millimeter / y_factor;
outline_size = x_size > y_size ? outline_size_in_millimeter / x_factor - inline_size: outline_size_in_millimeter / y_factor - inline_size;

 // Program Section //
//-----------------//

if(x_size > y_size) {
    resize(newsize=[max_size, x_factor * y_size, model_height]){
        if(flip_model == "yes") {
            mirror([0,1,0]) {
                rotate([180,180,0]) {
                    create(outline, cut_polygons);
                }
            }
        } else {
            create(outline, cut_polygons);
        }
    }
} else {
    resize(newsize=[y_factor * x_size, max_size, model_height]){
        if(flip_model == "yes") {
            mirror([0,1,0]) {
                rotate([180,180,0]) {
                    create(outline, cut_polygons);
                }
            }
        } else {
            create(outline, cut_polygons);
        }
    }
}

 // Module Section //
//----------------//

module create() {
    linear_extrude(height=1) {
        difference() {
            offset(r = -0) {
                offset(r = +outline_size) {
                    polygon(points = outline, convexity = 10);
                }
            }

            for(cut_polygon = [0:len(cut_polygons)]) {
                offset(r = +inline_edge_radius) {
                    offset(r = -inline_size - inline_edge_radius) {
                        polygon(points = cut_polygons[cut_polygon], convexity = 10);
                    }
                }
            }
        }
    }
}

```


[User]
Hi, I'm looking to create a parametric OpenSCAD module for voxelizing 3D models. I have a basic version, but I need it to be more flexible and have a few extra features.

Essentially, I want to take an existing 3D model (like an STL) and turn it into a voxelized representation, as if it were built from small cubes. I'm already familiar with the basic process of finding a bounding box and stepping through it.

Here's what I need it to do:

1.  **Parametric Bounding Box:** The module should accept parameters for defining the minimum and maximum points (p0, p1) of the bounding box as vectors, like \[x, y, z]. The default values are currently `[-10,-10,-10]` and `[10,10,10]` respectively.

2.  **Parametric Voxel Size:** The size of the individual voxels (cubes) should be controlled by a `step` parameter. I want to use `2` as the default step.

3.  **Parametric Overlap:** To ensure solid connections between voxels, the module should also have an `overlap` parameter. The default value should be `0.2`.

4.  **Import of Models:** The module should work with imported models, like STL files. I would like the module to import the model within its scope, if this is possible.

5.  **Center Option**: I need the option to center the voxelized model within the bounding box, or keep it aligned with the original min and max points of the import. Ideally, there should be a boolean parameter to control this - maybe `center_model=false` by default but it is easy to set to true.

6.  **Voxel Shape Option:** Instead of just cubes, I’d also like to allow for other voxel shapes. Maybe specify a shape parameter as a string, e.g. "cube" "sphere" "cylinder" so I can switch between them. In that case the step parameter should be interpreted as the diameter or width of the selected primitive shape.

7. **Output Only Voxel Option**: To allow this to be used for more complex applications, please add an output_only boolean parameter. If this is set to true, it should output only the voxelized model, and not render the original import at all. This should be `output_only=false` by default.

8.  **Advanced Options**:
    *   Provide a parameter to determine if the model should be rendered using convex hulls for each individual voxel. This might be slower but would be nice for some applications. Let's call it `use_convex_hull` and make it boolean, default to false.
    *   I'd like a parameter for the number of sides used when the voxel shape is a sphere or cylinder. Let's call this `voxel_sides`, and let the default value be 32.

The current `voxelize` module is very slow for complex objects, and I'm hoping this can be improved by making sure the imports and shape calculations are done efficiently. I'd also like the module to provide feedback on progress - maybe output the z-value as it slices, or the percentage complete, which would be helpful for large models. I understand that it might take a long time for a complex object, so outputting this information would be very helpful.

To be clear, I'm looking for a fully parametric module that incorporates all of these features. I don't need to use any specific libraries - just regular OpenSCAD functions, I don't want to require any external libraries like MCAD or BOSL to use it.

I'm looking forward to seeing what you can come up with!

[Assistant]
Voxelizer.scad:
```
/* Creates a voxel model out of the passed child element
    withn the volume from minimum point p0 the maximum point p1
    cube size is indicated by step.
    use overlap to make cubes a little bigger to avoid cubes
    touching only by edges or corners.

    Tips:
      * Use overlap of about 0.2 to be sure models are solid
        setting overlap to zero could mean voxels touching
        only by edges or corners.
      * Expect the voxelize function to take a long time.
        The included bunny included examples can take 15 to
        20 minuets or more to process.
      * Reduce complexity of models beforehand to reduce
        processing time improve success. E.g. the Benchy
        example was reduced by 95% in MeshMixer so it could
        successfully be processed by voxelize.
      * Offset the starting point, p0, by -1/2 step after
        finding the minimum for your model. This will improve
        symmetry since samples are taken at step boundries.

    Have fun! Don't forget to post your creations and let
       me know if you have any questions or suggestions.

   ~ QuantumZ
*/

module voxelize(p0=[-10,-10,-10],p1=[10,10,10],step=2,overlap=0.2){
  slicer(p0[2],p1[2],step,overlap)
    rotate([90,0,0]) slicer(p0[1],p1[1],step,overlap) rotate([-90,0,0])
      rotate([0,90,0]) slicer(p0[0],p1[0],step,overlap) rotate([0,-90,0])
        children();
}

// slicer slices child model parallel to the xy plane.
module slicer(z0,z1,step,overlap){
  for(z=[z0:step:z1]){
    translate([0,0,z])
      linear_extrude(height=step+overlap)
        projection(cut=true)
          translate([0,0,-z])
            children();
  }
}
```
bunny_example.scad:
```

// import the bunny.stl file and voxelize it to 2mm cubes

use<voxelizer.scad>

voxelize([-30,-22,-1],[20,20,50],2,0.2) import("bunny.stl");

```
benchy_example.scad:
```

// import the 3DBenchy_reduced.stl file and voxelize it to 1.5mm cubes

use<voxelizer.scad>

// Note: Using a version of 3DBenchy that has been reduced by 95% in MeshMixer.  They original was way too complex and caused OpenSCAD to error out.

voxelize([-32,-16,-1],[32,16,50],1.5,.2) import("3DBenchy_reduced.stl");

```


[User]
Hey, I'm looking to generate a printable bearing in OpenSCAD, and I'd like it to be parametric so I can easily adjust things like the size and number of rollers. I found a design that seems like a good starting point (I've attached the .scad file), but I would like a clean implementation of the design that could be used as the base for my own bearing designs. I'm not interested in an existing library but would like a clean design of my own.

Here's what I want:

**Overall Structure:**
The bearing should consist of an outer race, an inner race, a set of cylindrical rollers, and two retainers that keep the rollers spaced correctly. I want the design to be printable without supports.

**Parameters:**
I'd like to control these parameters:
*   `outerRadius`: The outer radius of the bearing.
*   `innerRadius`: The inner radius of the bearing.
*   `width`: The overall width of the bearing.
*   `tolerance`: The clearance between the rollers and the races. This is critical for smooth operation.
*   `numRollers`: The number of rollers in the bearing.
*   `wallThickness`: The thickness of the walls of the races and rollers (should be a multiple of the nozzle diameter).
*   `raceLipWidth`: The width of the lip on the races.
*   `rollerHoleRadius`: The radius of the hole through the center of the roller.
*   `retainerBaseHeight`: The height of the base of the retainer.

**Individual Components:**

*   **Outer Race:** A cylindrical ring with a lip on each side to contain the rollers.
*   **Inner Race:** A cylindrical ring with a lip on each side to contain the rollers, fitting inside the outer race.
*   **Rollers:** Cylindrical elements with a hole through the center. I'd like them to have chamfered edges so that they are easy to print.
*   **Retainers:** Two rings that sit on each side of the rollers, with pins that protrude into the roller's holes to keep them evenly spaced. I would like to be able to move these retainers independently of each other.

**Additional Notes:**
*   I'd prefer the code be organized into modules for each component, like `outerRace()`, `innerRace()`, `roller()`, and `retainer()`. I'd also like a combined module `all()` to display the full assembled bearing.
*   I need a module called `section()` that will create a cross-section of the bearing to show the internal geometries.
*   I need a `printPart()` module that will enable me to choose one of the previously mentioned modules.
*   The design should be fully parametric, meaning that all dimensions should be derived from the user-defined parameters I listed above.

I know this is a lot to ask for, but I want something flexible enough to experiment with. Thanks!

[Assistant]
bearing.scad:
```
/* [Basic] */

// Which one would you like to see?
part = "all"; // [all:Everything, outer: Outer Race, inner:Inner Race, roller:One Roller, retainer: One Retainer, section:Cross section]

// Render quality
$fn=200; //[20:Fast viewing, 200:Quality printing]

// Outer radius
outerRadius = 18;  //[14:0.5:50]

// Inner radius
innerRadius = 6;  //[3.5:0.5:45]

// Width
width = 13;  //[10:0.5:50]

// Tolerance (extra space between rollers and races)
tolerance = 0.2;  //[0.05:0.05:0.5]

// Number of rollers
numRollers = 7;  //[3:50]

/* [Advanced] */

// Thickness of walls (should be a multiple of your nozzle diameter)
wallThickness = 0.8;  //[0.1:0.1:5]

raceLipWidth = 2;

rollerHoleRadius = 2;

retainerBaseHeight = 0.6;  //[0.2:0.1:1]

outerRace = outerRadius - wallThickness;
innerRace = innerRadius + wallThickness;
rollerRadius = (outerRace - innerRace)/2 - tolerance;
rollerCentreDistance = innerRadius+wallThickness+tolerance+rollerRadius;
rollerHeight = width-2*(1+tolerance/0.707);
rollerVerticalOffset= 1+tolerance/0.707;

//echo (rollerRadius);

module outerHalf(){
    difference(){
        cylinder(width/2, outerRadius, outerRadius);

        translate([0,0,raceLipWidth+0.98])
        cylinder(width, outerRace, outerRace);

        //race lip
        translate([0,0,0.99])
        cylinder(raceLipWidth, outerRace-raceLipWidth, outerRace);

        translate([0,0,-0.02])
        cylinder(1.02, outerRace-raceLipWidth, outerRace-raceLipWidth);

        //chamfer
        translate([0,0,-0.02])
        difference(){
            cylinder(2, outerRadius+1, outerRadius+1);
            cylinder(2, outerRadius-1, outerRadius+1);

        }
    }
}

module outer(){
    difference(){
        union(){
            outerHalf();
            translate([0,0,width])
            mirror([0,0,1])
            outerHalf();
        }
        translate([rollerCentreDistance,0,width/2])
        cylinder(width, rollerRadius, rollerRadius);
    }
}

module innerHalf(){
    difference(){
        union(){
            translate([0,0,1+raceLipWidth])
            cylinder(width/2 + 1, innerRace, innerRace);

            translate([0,0,0.99])
            cylinder(raceLipWidth + 0.01, innerRace+raceLipWidth, innerRace);

            translate([0,0,-0.01])
            cylinder(1.01, innerRace+raceLipWidth, innerRace+raceLipWidth);
        }

        //centre hole
        translate([0,0,-1])
        cylinder(width+2, innerRadius, innerRadius);

        //chamfer
        translate([0,0,-0.02])
        cylinder(2, innerRadius+1, innerRadius-1);
    }
}

module inner(){
    difference(){
        union(){
            innerHalf();
            translate([0,0,width])
            mirror([0,0,1])
            innerHalf();
            }
        translate([rollerCentreDistance,0,width/2])
        cylinder(width, rollerRadius, rollerRadius);
    }
}

module rollerHalf(){
    rollerOuterChamferHeight = raceLipWidth+1 - rollerVerticalOffset+tolerance*2;
    difference(){
        union(){
            translate([0,0,rollerOuterChamferHeight])
            cylinder(width/2-wallThickness, rollerRadius, rollerRadius);

            cylinder(rollerOuterChamferHeight, rollerRadius-rollerOuterChamferHeight, rollerRadius);
        }

            translate([0,0,wallThickness+(rollerRadius-wallThickness) - rollerHoleRadius-0.01])
            cylinder(width, rollerRadius-wallThickness, rollerRadius-wallThickness);

            translate([0,0,wallThickness])
            cylinder((rollerRadius-wallThickness) - rollerHoleRadius, rollerHoleRadius, rollerRadius-wallThickness);

        translate([0,0,-1])
        cylinder(width, rollerHoleRadius, rollerHoleRadius);

    }
}

module roller(){
    rollerHalf();

    translate([0,0, rollerHeight])
    mirror([0,0,1])
    rollerHalf();
}

module rollers(){
    for (angle=[0:360/numRollers:360])
        rotate([0,0,angle])
        translate([rollerCentreDistance,0,0])
        roller();
}

module pin(){
    translate([-0.707*(wallThickness+rollerHoleRadius),0,wallThickness+tolerance*2+0.707*wallThickness+rollerHoleRadius])
    rotate([0,45,0])
    translate([0.84,0,(wallThickness+rollerHoleRadius)/4])
    cube([1.2*.707, 1.2, (wallThickness+rollerHoleRadius)/2], center=true);

    translate([0,0,wallThickness+tolerance*2])
    rotate([0,-45,0])
    translate([0,0,(wallThickness+rollerHoleRadius)/2])
    cube([1.2*.707, 1.2, wallThickness+rollerHoleRadius], center=true);

    translate([0,0,(rollerVerticalOffset+wallThickness)/2])
    cube([1.2, rollerHoleRadius*2-1.6, rollerVerticalOffset+wallThickness], center=true);
}

module retainer(){
    difference(){
        cylinder(retainerBaseHeight,rollerCentreDistance+1,rollerCentreDistance+1);
        translate([0,0,-1])
        cylinder(4,rollerCentreDistance-1,rollerCentreDistance-1);
    }

    for (angle=[0:360/numRollers:360])
        rotate([0,0,angle])
        translate([rollerCentreDistance,0,0])
        pin();
}

module all(){
    translate([0,0,0.01])
    retainer();

    translate([0,0,width])
    mirror([0,0,1])
    retainer();

    translate([0,0,rollerVerticalOffset])
    rollers();

    inner();
    outer();
}

module section(){
    difference(){
        all();
        translate([0,-50,-1])
        cube([50,50,50]);
    }
}

module printPart(){
    if (part == "all") {
		all();
	} else if (part == "outer") {
		outer();
	}else if (part == "inner") {
		inner();
    }else if (part == "roller") {
		roller();
    }else if (part == "retainer") {
		retainer();
    }else if (part == "section") {
		section();
	}
}

printPart();

//retainer();

//rollerHalf();
//roller();
//translate([0,0,2])
//rollers();

//inner();
//outer();

//all();
//section();

```


[User]
Hey, I'm trying to design some of these "fat coins" that can land on their edge. I saw Matt Parker's video about them, and I'd like to play around with different ratios of thickness to diameter.

I need an OpenSCAD file that can generate a cylinder. It should be parametric so I can change the diameter and the ratio of thickness to diameter. I'd like to be able to specify the diameter as a `d` value and the ratio as a `ratio` value, and the thickness should be calculated from those. I'd also like to include an option for a custom ratio, so if the ratio is set to 0, it uses the custom value instead.

The file should include a `$fn` variable for the resolution, and it should default to something like `100*1`. The coin should be a simple cylinder with the correct dimensions.

So, to summarize: I need an OpenSCAD file with variables `d`, `ratio`, `custom`, `final`, and `thickness` and which outputs a cylinder primitive with a thickness equal to `thickness` and a radius equal to `d/2`. I'd also need to set `$fn = 100*1`.

Can you help me with this?

[Assistant]
cylinder_coin.scad:
```
// mathgrrl cylinder coins
// for Matt Parker and Katie Steckles

/////////////////////////////////////////////////////////////////////////////
// PARAMETERS

// resolution
$fn = 100*1;

// diameter of the coin
d = 20;
r = d/2;

// select from popular thickness-to-diameter ratios
ratio = 2.82843; // [2.82843:1 to 2*sqrt(2), 2.7182818:1 to e, 2.3333333:1 to 7/3, 2:1 to 2, 1.7320508:1 to sqrt(3), 0:Enter Custom Ratio Below]

// only use if "custom" selected above; enter 1 to ?? ratio
custom = 0;

// set rainal ratio to be custom if ratio=0, and ratio otherwise
final = (ratio == 0) ? custom : ratio;

// thickness based on ratio
thickness = d/final;

/////////////////////////////////////////////////////////////////////////////
// RENDERS

cylinder(thickness,r,r);
```