// Parametric Pulley with multiple belt profiles
// by droftarts January 2012
// optimized for Thingiverse customizer February 2017
// hex shaft and hub hole support added by Tyler Bletsch, January 2019

// Based on pulleys by:
// http://www.thingiverse.com/thing:11256 by me!
// https://github.com/prusajr/PrusaMendel by Josef Prusa
// http://www.thingiverse.com/thing:3104 by GilesBathgate
// http://www.thingiverse.com/thing:2079 by nophead

// dxf tooth data from http://oem.cadregister.com/asp/PPOW_Entry.asp?company=915217&elementID=07807803/METRIC/URETH/WV0025/F
// pulley diameter checked and modelled from data at http://www.sdp-si.com/D265/HTML/D265T016.html

/**
 * @name Pulley
 * @category Printed
 * @using 1 x m3 nut, normal or nyloc
 * @using 1 x m3x10 set screw or 1 x m3x8 grub screw
 */

E = 0.001*1; // tiny value to nudge exactly-equal difference() issues away

// tuneable constants

// Number of teeth, standard Mendel T5 belt = 8, gives Outside Diameter of 11.88mm
teeth = 24; 	
// Select fundamental profile
profile = 10;		// [1:MXL, 2:40DP, 3:XL, 4:H, 5:T2.5, 6:T5, 7:T10, 8:AT5, 9:HTD_3mm, 10:HTD_5mm, 11:HTD_8mm, 12:GT2_2mm, 13:GT2_3mm, 14:GT2_5mm]

// Diameter of the motor shaft (NEMA17 motor shaft exact diameter = 5)
// NOTE: If added a hex shaft, set this smaller to the hex size (or to zero)
motor_shaft = 5.2;	
// 3mm hole diameter
m3_dia = 3.2;		
// Select nut type
m3_nut_hex = 1;		// [1: Hex Nut, 0:Square Nut]
// Width of  nut flats (normal M3 hex nut exact width = 5.5)
m3_nut_flats = 5.7;
// Depth of the nut (normal M3 hex nut exact depth = 2.4, nyloc = 4)
m3_nut_depth = 2.7;	

/* HEX SHAFT SUPPORT */

// enable hex shaft hole?
shaft_hex = true; // add a hex shaft

// size of hex hole across the flats in mm (12.954 is 0.5in with 2% margin)
shaft_hex_size = 12.954; // mm

// size of an optional chamfer (beveled edge) in mm
shaft_hex_chamfer = 1.0; // mm

/* HUB HOLES SUPPORT */

// Enable an array of holes on the pully (size permitting)?
hub_holes = true;

// Distance from center to put the holes (47.625mm (1.875") is the Vex VersaHub distance)
hub_holes_circle_dia = 47.625;

// Number of holes to drill (6 is the Vex VersaHub number)
hub_holes_count=6;

// Diameter of holes drilled in mm (4.4958mm (0.177") is the free fit diameter for a #8-32 screw, which is the Vex VersaHub size)
hub_holes_dia = 4.4958; 

// Minimum distance from hole to outer diameter of the pulley in mm
hub_hole_min_margin=6;

// Should a belt retainer be added above the teeth?
retainer = 1;		// [0:No, 1:Yes]
// Height of the retainer above teeth (default: 1.5)
retainer_ht = 1.5;	
// Should a belt retainer be added below the teeth?
idler = 1;			// [0:No, 1:Yes]
// Height of the retainer below teeth (default: 1.5)
idler_ht = 1.5;
// Length of toothed part of pulley (default: 12)
pulley_t_ht = 15;	
// Height of pulley base (default: 8 - Set to same as 'Idler Ht' if you want an idler but no pulley)
pulley_b_ht = 0;	
// Diameter of pulley base (default: 20)
pulley_b_dia = 20;	
// Number of captive nuts (default: 1)
no_of_nuts = 1;		
// Angle between nuts (default: 90)
nut_angle = 90;		
// Distance between inner face of nut and shaft (can be negative)
nut_shaft_distance = 1.2;	


/* [Tooth scaling] */

//	To improve fit of belt to pulley, set the following constant. Decrease or increase by 0.1mm at a time. We are modelling the *BELT* tooth here, not the tooth on the pulley. Increasing the number will *decrease* the pulley tooth size. Increasing the tooth width will also scale proportionately the tooth depth, to maintain the shape of the tooth, and increase how far into the pulley the tooth is indented. Can be negative
additional_tooth_width = 0.2; //mm

//	If you need more tooth depth than this provides, adjust the following constant. However, this will cause the shape of the tooth to change.
additional_tooth_depth = 0; //mm

// calculated constants

nut_elevation = pulley_b_ht/2;
m3_nut_points = 2*((m3_nut_flats/2)/cos(30)); // This is needed for the nut trap

// The following set the pulley diameter for a given number of teeth

MXL_pulley_dia = tooth_spacing (2.032,0.254);
40DP_pulley_dia = tooth_spacing (2.07264,0.1778);
XL_pulley_dia = tooth_spacing (5.08,0.254);
H_pulley_dia = tooth_spacing (9.525,0.381);
T2_5_pulley_dia = tooth_spaceing_curvefit (0.7467,0.796,1.026);
T5_pulley_dia = tooth_spaceing_curvefit (0.6523,1.591,1.064);
T10_pulley_dia = tooth_spacing (10,0.93);
AT5_pulley_dia = tooth_spaceing_curvefit (0.6523,1.591,1.064);
HTD_3mm_pulley_dia = tooth_spacing (3,0.381);
HTD_5mm_pulley_dia = tooth_spacing (5,0.5715);
HTD_8mm_pulley_dia = tooth_spacing (8,0.6858);
GT2_2mm_pulley_dia = tooth_spacing (2,0.254);
GT2_3mm_pulley_dia = tooth_spacing (3,0.381);
GT2_5mm_pulley_dia = tooth_spacing (5,0.5715);

// The following calls the pulley creation part, and passes the pulley diameter and tooth width to that module

if ( profile == 1 ) { pulley ( "MXL" , MXL_pulley_dia , 0.508 , 1.321 ); }
if ( profile == 2 ) { pulley ( "40 D.P." , 40DP_pulley_dia , 0.457 , 1.226 ); }
if ( profile == 3 ) { pulley ( "XL" , XL_pulley_dia , 1.27, 3.051 ); }
if ( profile == 4 ) { pulley ( "H" , H_pulley_dia ,1.905 , 5.359 ); }
if ( profile == 5 ) { pulley ( "T2.5" , T2_5_pulley_dia , 0.7 , 1.678 ); }
if ( profile == 6 ) { pulley ( "T5" , T5_pulley_dia , 1.19 , 3.264 ); }
if ( profile == 7 ) { pulley ( "T10" , T10_pulley_dia , 2.5 , 6.13 ); }
if ( profile == 8 ) { pulley ( "AT5" , AT5_pulley_dia , 1.19 , 4.268 ); }
if ( profile == 9 ) { pulley ( "HTD 3mm" , HTD_3mm_pulley_dia , 1.289 , 2.27 ); }
if ( profile == 10 ) { pulley ( "HTD 5mm" , HTD_5mm_pulley_dia , 2.199 , 3.781 ); }
if ( profile == 11 ) { pulley ( "HTD 8mm" , HTD_8mm_pulley_dia , 3.607 , 6.603 ); }
if ( profile == 12 ) { pulley ( "GT2 2mm" , GT2_2mm_pulley_dia , 0.764 , 1.494 ); }
if ( profile == 13 ) { pulley ( "GT2 3mm" , GT2_3mm_pulley_dia , 1.169 , 2.31 ); }
if ( profile == 14 ) { pulley ( "GT2 5mm" , GT2_5mm_pulley_dia , 1.969 , 3.952 ); }

// Functions

function tooth_spaceing_curvefit (b,c,d)
	= ((c * pow(teeth,d)) / (b + pow(teeth,d))) * teeth ;

function tooth_spacing(tooth_pitch,pitch_line_offset)
	= (2*((teeth*tooth_pitch)/(3.14159265*2)-pitch_line_offset)) ;

// Main Module

module pulley( belt_type , pulley_OD , tooth_depth , tooth_width )
	{
	echo (str("Belt type = ",belt_type,"; Number of teeth = ",teeth,"; Pulley Outside Diameter = ",pulley_OD,"mm "));
	tooth_distance_from_centre = sqrt( pow(pulley_OD/2,2) - pow((tooth_width+additional_tooth_width)/2,2));
	tooth_width_scale = (tooth_width + additional_tooth_width ) / tooth_width;
	tooth_depth_scale = ((tooth_depth + additional_tooth_depth ) / tooth_depth) ;


//	************************************************************************
//	*** uncomment the following line if pulley is wider than puller base ***
//	************************************************************************

//	translate ([0,0, pulley_b_ht + pulley_t_ht + retainer_ht ]) rotate ([0,180,0])

	difference()
	 {	 
		union()
		{
			//base
	
			if ( pulley_b_ht < 2 ) { echo ("CAN'T DRAW PULLEY BASE, HEIGHT LESS THAN 2!!!"); } else {
				rotate_extrude($fn=pulley_b_dia*2)
				{
						square([pulley_b_dia/2-1,pulley_b_ht]);
						square([pulley_b_dia/2,pulley_b_ht-1]);
						translate([pulley_b_dia/2-1,pulley_b_ht-1]) circle(1);
				}
			}
	
		difference()
			{
			//shaft - diameter is outside diameter of pulley
			
			translate([0,0,pulley_b_ht]) 
			rotate ([0,0,360/(teeth*4)]) 
			cylinder(r=pulley_OD/2,h=pulley_t_ht, $fn=teeth*4);
	
			//teeth - cut out of shaft
		
			for(i=[1:teeth]) 
			rotate([0,0,i*(360/teeth)])
			translate([0,-tooth_distance_from_centre,pulley_b_ht -1]) 
			scale ([ tooth_width_scale , tooth_depth_scale , 1 ]) 
			{
			if ( profile == 1 ) { MXL();}
			if ( profile == 2 ) { 40DP();}
			if ( profile == 3 ) { XL();}
			if ( profile == 4 ) { H();}
			if ( profile == 5 ) { T2_5();}
			if ( profile == 6 ) { T5();}
			if ( profile == 7 ) { T10();}
			if ( profile == 8 ) { AT5();}
			if ( profile == 9 ) { HTD_3mm();}
			if ( profile == 10 ) { HTD_5mm();}
			if ( profile == 11 ) { HTD_8mm();}
			if ( profile == 12 ) { GT2_2mm();}
			if ( profile == 13 ) { GT2_3mm();}
			if ( profile == 14 ) { GT2_5mm();}
			}

			}
			
		//belt retainer / idler
		if ( retainer > 0 ) {translate ([0,0, pulley_b_ht + pulley_t_ht ]) 
		rotate_extrude($fn=teeth*4)  
		polygon([[0,0],[pulley_OD/2,0],[pulley_OD/2 + retainer_ht , retainer_ht],[0 , retainer_ht],[0,0]]);}
		
		if ( idler > 0 ) {translate ([0,0, pulley_b_ht - idler_ht ]) 
		rotate_extrude($fn=teeth*4)  
		polygon([[0,0],[pulley_OD/2 + idler_ht,0],[pulley_OD/2 , idler_ht],[0 , idler_ht],[0,0]]);}
	
		}
	   
		//hole for motor shaft
		translate([0,0,-1])cylinder(r=motor_shaft/2,h=pulley_b_ht + pulley_t_ht + retainer_ht + 2,$fn=motor_shaft*4);
				
		//captive nut and grub screw holes
	
		if ( pulley_b_ht < m3_nut_flats ) { echo ("CAN'T DRAW CAPTIVE NUTS, HEIGHT LESS THAN NUT DIAMETER!!!"); } else {
		if ( (pulley_b_dia - motor_shaft)/2 < m3_nut_depth + 3 ) { echo ("CAN'T DRAW CAPTIVE NUTS, DIAMETER TOO SMALL FOR NUT DEPTH!!!"); } else {
	
			for(j=[1:no_of_nuts]) rotate([0,0,j*nut_angle])
			translate([0,0,nut_elevation])rotate([90,0,0])
	
			union()
			{
				//entrance
				translate([0,-pulley_b_ht/4-0.5,motor_shaft/2+m3_nut_depth/2+nut_shaft_distance]) cube([m3_nut_flats,pulley_b_ht/2+1,m3_nut_depth],center=true);
	
				//nut
				if ( m3_nut_hex > 0 )
					{
						// hex nut
						translate([0,0.25,motor_shaft/2+m3_nut_depth/2+nut_shaft_distance]) rotate([0,0,30]) cylinder(r=m3_nut_points/2,h=m3_nut_depth,center=true,$fn=6);
					} else {
						// square nut
						translate([0,0.25,motor_shaft/2+m3_nut_depth/2+nut_shaft_distance]) cube([m3_nut_flats,m3_nut_flats,m3_nut_depth],center=true);
					}
	
				//grub screw hole
				rotate([0,0,22.5])cylinder(r=m3_dia/2,h=pulley_b_dia/2+1,$fn=8);
			}
		}}
        
        if (shaft_hex) {
            shaft_hex_dia = shaft_hex_size*2/sqrt(3); // we use a 6-point circle for our hex; this math converts flat-to-flat size to point-to-point diameter.
            translate([0,0,-idler_ht-E]) cylinder($fn=6,d=shaft_hex_dia,h=pulley_b_ht + pulley_t_ht + retainer_ht + idler_ht + 2*E);
            if (shaft_hex_chamfer) {
                translate([0,0,pulley_b_ht+pulley_t_ht+retainer_ht-shaft_hex_chamfer]) cylinder($fn=6,d2=shaft_hex_dia+shaft_hex_chamfer*2,d1=shaft_hex_dia,h=shaft_hex_chamfer+E);
                translate([0,0,-idler_ht-E]) cylinder($fn=6,d1=shaft_hex_dia+shaft_hex_chamfer*2,d2=shaft_hex_dia,h=shaft_hex_chamfer+2*E);
            }
        }
        
        if (hub_holes) {
            if (hub_holes_circle_dia+hub_holes_dia <= pulley_OD-hub_hole_min_margin) {
                for(j=[1:hub_holes_count]) rotate([0,0,j*360/hub_holes_count])
			translate([hub_holes_circle_dia/2,0,-idler_ht-E]) #cylinder(d=hub_holes_dia,h=pulley_b_ht + pulley_t_ht + retainer_ht + idler_ht + 2*E,$fn=20);
	
            } else {
                echo("Pulley too small for specified hub holes! (OD=",pulley_OD,", hub_holes_circle_dia+hub_holes_dia=",hub_holes_circle_dia+hub_holes_dia);
            }
        }
        
        
        // x-ray cutaway to check geometry
        //translate([0,-40,6]) cube([40,80,40]);
        
	 }
	   
	}


// Tooth profile modules

module MXL()
	{
	linear_extrude(height=pulley_t_ht+2) polygon([[-0.660421,-0.5],[-0.660421,0],[-0.621898,0.006033],[-0.587714,0.023037],[-0.560056,0.049424],[-0.541182,0.083609],[-0.417357,0.424392],[-0.398413,0.458752],[-0.370649,0.48514],[-0.336324,0.502074],[-0.297744,0.508035],[0.297744,0.508035],[0.336268,0.502074],[0.370452,0.48514],[0.39811,0.458752],[0.416983,0.424392],[0.540808,0.083609],[0.559752,0.049424],[0.587516,0.023037],[0.621841,0.006033],[0.660421,0],[0.660421,-0.5]]);
	}

module 40DP()
	{
	linear_extrude(height=pulley_t_ht+2) polygon([[-0.612775,-0.5],[-0.612775,0],[-0.574719,0.010187],[-0.546453,0.0381],[-0.355953,0.3683],[-0.327604,0.405408],[-0.291086,0.433388],[-0.248548,0.451049],[-0.202142,0.4572],[0.202494,0.4572],[0.248653,0.451049],[0.291042,0.433388],[0.327609,0.405408],[0.356306,0.3683],[0.546806,0.0381],[0.574499,0.010187],[0.612775,0],[0.612775,-0.5]]);
	}

module XL()
	{
	linear_extrude(height=pulley_t_ht+2) polygon([[-1.525411,-1],[-1.525411,0],[-1.41777,0.015495],[-1.320712,0.059664],[-1.239661,0.129034],[-1.180042,0.220133],[-0.793044,1.050219],[-0.733574,1.141021],[-0.652507,1.210425],[-0.555366,1.254759],[-0.447675,1.270353],[0.447675,1.270353],[0.555366,1.254759],[0.652507,1.210425],[0.733574,1.141021],[0.793044,1.050219],[1.180042,0.220133],[1.239711,0.129034],[1.320844,0.059664],[1.417919,0.015495],[1.525411,0],[1.525411,-1]]);
	}

module H()
	{
	linear_extrude(height=pulley_t_ht+2) polygon([[-2.6797,-1],[-2.6797,0],[-2.600907,0.006138],[-2.525342,0.024024],[-2.45412,0.052881],[-2.388351,0.091909],[-2.329145,0.140328],[-2.277614,0.197358],[-2.234875,0.262205],[-2.202032,0.334091],[-1.75224,1.57093],[-1.719538,1.642815],[-1.676883,1.707663],[-1.62542,1.764693],[-1.566256,1.813112],[-1.500512,1.85214],[-1.4293,1.880997],[-1.353742,1.898883],[-1.274949,1.905021],[1.275281,1.905021],[1.354056,1.898883],[1.429576,1.880997],[1.500731,1.85214],[1.566411,1.813112],[1.625508,1.764693],[1.676919,1.707663],[1.719531,1.642815],[1.752233,1.57093],[2.20273,0.334091],[2.235433,0.262205],[2.278045,0.197358],[2.329455,0.140328],[2.388553,0.091909],[2.454233,0.052881],[2.525384,0.024024],[2.600904,0.006138],[2.6797,0],[2.6797,-1]]);
	}

module T2_5()
	{
	linear_extrude(height=pulley_t_ht+2) polygon([[-0.839258,-0.5],[-0.839258,0],[-0.770246,0.021652],[-0.726369,0.079022],[-0.529167,0.620889],[-0.485025,0.67826],[-0.416278,0.699911],[0.416278,0.699911],[0.484849,0.67826],[0.528814,0.620889],[0.726369,0.079022],[0.770114,0.021652],[0.839258,0],[0.839258,-0.5]]);
	}

module T5()
	{
	linear_extrude(height=pulley_t_ht+2) polygon([[-1.632126,-0.5],[-1.632126,0],[-1.568549,0.004939],[-1.507539,0.019367],[-1.450023,0.042686],[-1.396912,0.074224],[-1.349125,0.113379],[-1.307581,0.159508],[-1.273186,0.211991],[-1.246868,0.270192],[-1.009802,0.920362],[-0.983414,0.978433],[-0.949018,1.030788],[-0.907524,1.076798],[-0.859829,1.115847],[-0.80682,1.147314],[-0.749402,1.170562],[-0.688471,1.184956],[-0.624921,1.189895],[0.624971,1.189895],[0.688622,1.184956],[0.749607,1.170562],[0.807043,1.147314],[0.860055,1.115847],[0.907754,1.076798],[0.949269,1.030788],[0.9837,0.978433],[1.010193,0.920362],[1.246907,0.270192],[1.273295,0.211991],[1.307726,0.159508],[1.349276,0.113379],[1.397039,0.074224],[1.450111,0.042686],[1.507589,0.019367],[1.568563,0.004939],[1.632126,0],[1.632126,-0.5]]);
	}

module T10()
	{
	linear_extrude(height=pulley_t_ht+2) polygon([[-3.06511,-1],[-3.06511,0],[-2.971998,0.007239],[-2.882718,0.028344],[-2.79859,0.062396],[-2.720931,0.108479],[-2.651061,0.165675],[-2.590298,0.233065],[-2.539962,0.309732],[-2.501371,0.394759],[-1.879071,2.105025],[-1.840363,2.190052],[-1.789939,2.266719],[-1.729114,2.334109],[-1.659202,2.391304],[-1.581518,2.437387],[-1.497376,2.47144],[-1.408092,2.492545],[-1.314979,2.499784],[1.314979,2.499784],[1.408091,2.492545],[1.497371,2.47144],[1.581499,2.437387],[1.659158,2.391304],[1.729028,2.334109],[1.789791,2.266719],[1.840127,2.190052],[1.878718,2.105025],[2.501018,0.394759],[2.539726,0.309732],[2.59015,0.233065],[2.650975,0.165675],[2.720887,0.108479],[2.798571,0.062396],[2.882713,0.028344],[2.971997,0.007239],[3.06511,0],[3.06511,-1]]);
	}

module AT5()
	{
	linear_extrude(height=pulley_t_ht+2) polygon([[-2.134129,-0.75],[-2.134129,0],[-2.058023,0.005488],[-1.984595,0.021547],[-1.914806,0.047569],[-1.849614,0.082947],[-1.789978,0.127073],[-1.736857,0.179338],[-1.691211,0.239136],[-1.653999,0.305859],[-1.349199,0.959203],[-1.286933,1.054635],[-1.201914,1.127346],[-1.099961,1.173664],[-0.986896,1.18992],[0.986543,1.18992],[1.099614,1.173664],[1.201605,1.127346],[1.286729,1.054635],[1.349199,0.959203],[1.653646,0.305859],[1.690859,0.239136],[1.73651,0.179338],[1.789644,0.127073],[1.849305,0.082947],[1.914539,0.047569],[1.984392,0.021547],[2.057906,0.005488],[2.134129,0],[2.134129,-0.75]]);
	}

module HTD_3mm()
	{
	linear_extrude(height=pulley_t_ht+2) polygon([[-1.135062,-0.5],[-1.135062,0],[-1.048323,0.015484],[-0.974284,0.058517],[-0.919162,0.123974],[-0.889176,0.206728],[-0.81721,0.579614],[-0.800806,0.653232],[-0.778384,0.72416],[-0.750244,0.792137],[-0.716685,0.856903],[-0.678005,0.918199],[-0.634505,0.975764],[-0.586483,1.029338],[-0.534238,1.078662],[-0.47807,1.123476],[-0.418278,1.16352],[-0.355162,1.198533],[-0.289019,1.228257],[-0.22015,1.25243],[-0.148854,1.270793],[-0.07543,1.283087],[-0.000176,1.28905],[0.075081,1.283145],[0.148515,1.270895],[0.219827,1.252561],[0.288716,1.228406],[0.354879,1.19869],[0.418018,1.163675],[0.477831,1.123623],[0.534017,1.078795],[0.586276,1.029452],[0.634307,0.975857],[0.677809,0.91827],[0.716481,0.856953],[0.750022,0.792167],[0.778133,0.724174],[0.800511,0.653236],[0.816857,0.579614],[0.888471,0.206728],[0.919014,0.123974],[0.974328,0.058517],[1.048362,0.015484],[1.135062,0],[1.135062,-0.5]]);
	}

module HTD_5mm()
	{
	linear_extrude(height=pulley_t_ht+2) polygon([[-1.89036,-0.75],[-1.89036,0],[-1.741168,0.02669],[-1.61387,0.100806],[-1.518984,0.21342],[-1.467026,0.3556],[-1.427162,0.960967],[-1.398568,1.089602],[-1.359437,1.213531],[-1.310296,1.332296],[-1.251672,1.445441],[-1.184092,1.552509],[-1.108081,1.653042],[-1.024167,1.746585],[-0.932877,1.832681],[-0.834736,1.910872],[-0.730271,1.980701],[-0.62001,2.041713],[-0.504478,2.09345],[-0.384202,2.135455],[-0.259708,2.167271],[-0.131524,2.188443],[-0.000176,2.198511],[0.131296,2.188504],[0.259588,2.167387],[0.384174,2.135616],[0.504527,2.093648],[0.620123,2.04194],[0.730433,1.980949],[0.834934,1.911132],[0.933097,1.832945],[1.024398,1.746846],[1.108311,1.653291],[1.184308,1.552736],[1.251865,1.445639],[1.310455,1.332457],[1.359552,1.213647],[1.39863,1.089664],[1.427162,0.960967],[1.467026,0.3556],[1.518984,0.21342],[1.61387,0.100806],[1.741168,0.02669],[1.89036,0],[1.89036,-0.75]]);
	}

module HTD_8mm()
	{
	linear_extrude(height=pulley_t_ht+2) polygon([[-3.301471,-1],[-3.301471,0],[-3.16611,0.012093],[-3.038062,0.047068],[-2.919646,0.10297],[-2.813182,0.177844],[-2.720989,0.269734],[-2.645387,0.376684],[-2.588694,0.496739],[-2.553229,0.627944],[-2.460801,1.470025],[-2.411413,1.691917],[-2.343887,1.905691],[-2.259126,2.110563],[-2.158035,2.30575],[-2.041518,2.490467],[-1.910478,2.66393],[-1.76582,2.825356],[-1.608446,2.973961],[-1.439261,3.10896],[-1.259169,3.22957],[-1.069074,3.335006],[-0.869878,3.424485],[-0.662487,3.497224],[-0.447804,3.552437],[-0.226732,3.589341],[-0.000176,3.607153],[0.226511,3.589461],[0.447712,3.552654],[0.66252,3.497516],[0.870027,3.424833],[1.069329,3.33539],[1.259517,3.229973],[1.439687,3.109367],[1.608931,2.974358],[1.766344,2.825731],[1.911018,2.664271],[2.042047,2.490765],[2.158526,2.305998],[2.259547,2.110755],[2.344204,1.905821],[2.411591,1.691983],[2.460801,1.470025],[2.553229,0.627944],[2.588592,0.496739],[2.645238,0.376684],[2.720834,0.269734],[2.81305,0.177844],[2.919553,0.10297],[3.038012,0.047068],[3.166095,0.012093],[3.301471,0],[3.301471,-1]]);
	}

module GT2_2mm()
	{
	linear_extrude(height=pulley_t_ht+2) polygon([[0.747183,-0.5],[0.747183,0],[0.647876,0.037218],[0.598311,0.130528],[0.578556,0.238423],[0.547158,0.343077],[0.504649,0.443762],[0.451556,0.53975],[0.358229,0.636924],[0.2484,0.707276],[0.127259,0.750044],[0,0.76447],[-0.127259,0.750044],[-0.2484,0.707276],[-0.358229,0.636924],[-0.451556,0.53975],[-0.504797,0.443762],[-0.547291,0.343077],[-0.578605,0.238423],[-0.598311,0.130528],[-0.648009,0.037218],[-0.747183,0],[-0.747183,-0.5]]);
	}

module GT2_3mm()
	{
	linear_extrude(height=pulley_t_ht+2) polygon([[-1.155171,-0.5],[-1.155171,0],[-1.065317,0.016448],[-0.989057,0.062001],[-0.93297,0.130969],[-0.90364,0.217664],[-0.863705,0.408181],[-0.800056,0.591388],[-0.713587,0.765004],[-0.60519,0.926747],[-0.469751,1.032548],[-0.320719,1.108119],[-0.162625,1.153462],[0,1.168577],[0.162625,1.153462],[0.320719,1.108119],[0.469751,1.032548],[0.60519,0.926747],[0.713587,0.765004],[0.800056,0.591388],[0.863705,0.408181],[0.90364,0.217664],[0.932921,0.130969],[0.988924,0.062001],[1.065168,0.016448],[1.155171,0],[1.155171,-0.5]]);
	}

module GT2_5mm()
	{
	linear_extrude(height=pulley_t_ht+2) polygon([[-1.975908,-0.75],[-1.975908,0],[-1.797959,0.03212],[-1.646634,0.121224],[-1.534534,0.256431],[-1.474258,0.426861],[-1.446911,0.570808],[-1.411774,0.712722],[-1.368964,0.852287],[-1.318597,0.989189],[-1.260788,1.123115],[-1.195654,1.25375],[-1.12331,1.380781],[-1.043869,1.503892],[-0.935264,1.612278],[-0.817959,1.706414],[-0.693181,1.786237],[-0.562151,1.851687],[-0.426095,1.9027],[-0.286235,1.939214],[-0.143795,1.961168],[0,1.9685],[0.143796,1.961168],[0.286235,1.939214],[0.426095,1.9027],[0.562151,1.851687],[0.693181,1.786237],[0.817959,1.706414],[0.935263,1.612278],[1.043869,1.503892],[1.123207,1.380781],[1.195509,1.25375],[1.26065,1.123115],[1.318507,0.989189],[1.368956,0.852287],[1.411872,0.712722],[1.447132,0.570808],[1.474611,0.426861],[1.534583,0.256431],[1.646678,0.121223],[1.798064,0.03212],[1.975908,0],[1.975908,-0.75]]);
	}