1 // OpenSCAD Herringbone Wade's Gears Script
2 // (c) 2011, Christopher "ScribbleJ" Jansen
4 // Thanks to Greg Frost for his great "Involute Gears" script.
6 // Licensed under the BSD license.
8 // Adapted for Reprap Wilson by Martin Rice
11 include <MCAD/involute_gears.scad>
15 generate = 0; // GENERATE BOTH GEARS FOR VIEWING
16 // generate = 1; // GENERATE STEPPER GEAR FOR PRINTING
17 generate = 2; // GENERATE DRIVE GEAR FOR PRINTING
19 // OPTIONS COMMON TO BOTH GEARS:
20 distance_between_axels = 42;
30 // GEAR1 (SMALLER GEAR, STEPPER GEAR) OPTIONS:
31 // It's helpful to choose prime numbers for the gear teeth.
33 gear1_shaft_d = 5.5; // diameter of motor shaft
34 gear1_shaft_r = gear1_shaft_d/2;
35 // gear1 shaft assumed to fill entire gear.
36 // gear1 attaches by means of a captive nut and bolt (or actual setscrew)
37 gear1_setscrew_offset = 5; // Distance from motor on motor shaft.
38 gear1_setscrew_d = 3.5;
39 gear1_setscrew_r = gear1_setscrew_d/2;
40 gear1_captive_nut_d = 6;
41 gear1_captive_nut_r = gear1_captive_nut_d/2;
42 gear1_captive_nut_h = 2.5;
45 // GEAR2 (LARGER GEAR, DRIVE SHAFT GEAR) OPTIONS:
48 gear2_shaft_r = gear2_shaft_d/2;
49 // gear2 has settable outer shaft diameter.
50 gear2_shaft_outer_d = 16;
51 gear2_shaft_outer_r = gear2_shaft_outer_d/2;
53 // gear2 has a hex bolt set in it, is either a hobbed bolt or has the nifty hobbed gear from MBI on it.
54 gear2_bolt_hex_d = 15;
55 gear2_bolt_hex_r = gear2_bolt_hex_d/2;
56 // gear2_bolt_sink: How far down the gear shaft the bolt head sits; measured as distance from drive end of gear.
58 // gear2's shaft is a bridge above the hex bolt shaft; this creates 1/3bridge_helper_h sized steps at top of shaft to help bridging. (so bridge_helper_h/3 should be > layer height to have any effect)
62 gear2_cut_circles = 5;
64 // gear2 setscrew option; not likely needed.
65 gear2_setscrew_offset = 0;
67 gear2_setscrew_r = gear2_setscrew_d/2;
68 // captive nut for the setscrew
69 gear2_captive_nut_d = 0;
70 gear2_captive_nut_r = gear2_captive_nut_d/2;
71 gear2_captive_nut_h = 0;
74 // Tolerances for geometry connections.
80 module bridge_helper()
84 translate([0,0,-bridge_helper_h/2])
85 cylinder(r=gear2_bolt_hex_r+TT, h=bridge_helper_h+TT,$fn=6,center=true);
86 #translate([0,0,-bridge_helper_h/2])
87 cube([gear2_bolt_hex_d+ST, gear2_shaft_d, bridge_helper_h+AT], center=true);
93 module gearsbyteethanddistance(t1=13,t2=51, d=60, teethtwist=1, which=1)
97 g1twist = 360 * teethtwist / t1 / 2;
98 g2twist = 360 * teethtwist / t2 / 2;
100 g1p_d = t1 * cp / 180;
101 g2p_d = t2 * cp / 180;
105 echo(str("Your small ", t1, "-toothed gear will be ", g1p_d, "mm across (plus 1 gear tooth size) (PR=", g1p_r,")"));
106 echo(str("Your large ", t2, "-toothed gear will be ", g2p_d, "mm across (plus 1 gear tooth size) (PR=", g2p_r,")"));
107 echo(str("Your minimum drive bolt length (to end of gear) is: ", gear2_bolt_sink+bridge_helper_h, "mm and your max is: ", gear_h+gear_shaft_h, "mm."));
108 echo(str("Your gear mount axles should be ", d,"mm (", g1p_r+g2p_r,"mm calculated) from each other."));
116 translate([0,0,(gear_h/2) - TT])
117 gear( twist = g1twist,
120 gear_thickness = gear_shaft_h + (gear_h/2)+AT,
121 rim_thickness = (gear_h/2)+AT,
123 hub_thickness = (gear_h/2)+AT,
127 translate([0,0,(gear_h/2) + AT])
129 gear( twist = -g1twist,
132 gear_thickness = (gear_h/2)+AT,
133 rim_thickness = (gear_h/2)+AT,
134 hub_thickness = (gear_h/2)+AT,
140 cylinder(r=gear1_shaft_r, h=gear_h+gear_shaft_h+ST);
143 translate([0,0,gear_h+gear_shaft_h-gear1_setscrew_offset])
145 cylinder(r=gear1_setscrew_r, h=g1p_r);
147 //setscrew captive nut
148 translate([(g1p_r)/2, 0, gear_h+gear_shaft_h-gear1_captive_nut_r-gear1_setscrew_offset])
149 translate([0,0,(gear1_captive_nut_r+gear1_setscrew_offset)/2])
150 #cube([gear1_captive_nut_h, gear1_captive_nut_d, gear1_captive_nut_r+gear1_setscrew_offset+ST],center=true);
162 // cylinder(h=gear_h+gear_shaft_h , r=gear2_shaft_outer_r);
164 translate([0,0,(gear_h/2) - TT])
165 gear( twist = -g2twist,
168 gear_thickness = gear_shaft_h + (gear_h/2)+AT,
169 rim_thickness = (gear_h/2)+AT,
170 rim_width = gear2_rim_margin,
171 hub_diameter = gear2_shaft_outer_d,
172 hub_thickness = (gear_h/2)+AT,
174 circles = gear2_cut_circles);
176 translate([0,0,(gear_h/2) + AT])
178 gear( twist = g2twist,
181 gear_thickness = (gear_h/2)+AT,
182 rim_thickness = (gear_h/2)+AT,
183 rim_width = gear2_rim_margin,
184 hub_diameter = gear2_shaft_outer_d,
185 hub_thickness = (gear_h/2)+AT,
187 circles = gear2_cut_circles);
193 cylinder(r=gear2_shaft_r, h=gear_h+gear_shaft_h+ST);
197 translate([0,0,gear_h+gear_shaft_h-gear2_setscrew_offset])
199 cylinder(r=gear2_setscrew_r, h=gear2_shaft_outer_d);
201 //setscrew captive nut
202 translate([(gear2_shaft_outer_d)/2, 0, gear_h+gear_shaft_h-gear2_captive_nut_r-gear2_setscrew_offset])
203 translate([0,0,(gear2_captive_nut_r+gear2_setscrew_offset)/2])
204 #cube([gear2_captive_nut_h, gear2_captive_nut_d, gear2_captive_nut_r+gear2_setscrew_offset+ST],center=true);
210 translate([0,0,gear_h+AT]) cylinder(h=gear_shaft_h+ST, r=g2p_r);
211 #translate([0,0,gear_h]) cylinder(h=gear_shaft_h , r=gear2_shaft_outer_r);
215 translate([0,0,-TT]) cylinder(r=gear2_bolt_hex_r, h=gear2_bolt_sink+AT,$fn=6);
219 if(1) translate([0,0,1]) {
220 // hex bolt shaft bridge aid.
221 #translate([0,0,gear2_bolt_sink]) //gear_h+gear_shaft_h-gear2_bolt_sink])
223 #translate([0,0,gear2_bolt_sink-bridge_helper_h/3]) //gear_h+gear_shaft_h-gear2_bolt_sink+bridge_helper_h/3])
224 rotate([0,0,60]) bridge_helper();
225 #translate([0,0,gear2_bolt_sink-(bridge_helper_h/3*2)]) //gear_h+gear_shaft_h-gear2_bolt_sink+((bridge_helper_h/3)*2)])
226 rotate([0,0,-60]) bridge_helper();
235 cp = 360*distance_between_axels/(t1+t2);
236 g1p_d = t1 * cp / 180;
237 g2p_d = t2 * cp / 180;
243 gearsbyteethanddistance(t1 = gear1_teeth, t2=gear2_teeth, d=distance_between_axels, which=1);
245 else if(generate == 2)
247 gearsbyteethanddistance(t1 = gear1_teeth, t2=gear2_teeth, d=distance_between_axels, which=2);
252 translate([-g1p_r,0,0]) rotate([0,0,($t*360/gear1_teeth)]) gearsbyteethanddistance(t1 = gear1_teeth, t2=gear2_teeth, d=distance_between_axels, which=1);
253 translate([g2p_r,0,0]) rotate([0,0,($t*360/gear2_teeth)*-1]) gearsbyteethanddistance(t1 = gear1_teeth, t2=gear2_teeth, d=distance_between_axels, which=2);