You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

245 lines
7.3 KiB

// OpenSCAD Herringbone Wade's Gears Script
// (c) 2011, Christopher "ScribbleJ" Jansen
//
// Thanks to Greg Frost for his great "Involute Gears" script.
//
// Licensed under the BSD license.
include <MCAD/involute_gears.scad>
// WHAT TO GENERATE?
//generate = 0; // GENERATE BOTH GEARS FOR VIEWING
generate = 0; // GENERATE STEPPER GEAR FOR PRINTING
// generate = 2; // GENERATE DRIVE GEAR FOR PRINTING
// OPTIONS COMMON TO BOTH GEARS:
distance_between_axels = 60;
gear_h = 10;
gear_shaft_h = 6;
// GEAR1 (SMALLER GEAR, STEPPER GEAR) OPTIONS:
// It's helpful to choose prime numbers for the gear teeth.
gear1_teeth = 13;
gear1_shaft_d = 5.5; // diameter of motor shaft
gear1_shaft_r = gear1_shaft_d/2;
// gear1 shaft assumed to fill entire gear.
// gear1 attaches by means of a captive nut and bolt (or actual setscrew)
gear1_setscrew_offset = 5; // Distance from motor on motor shaft.
gear1_setscrew_d = 3.5;
gear1_setscrew_r = gear1_setscrew_d/2;
gear1_captive_nut_d = 6.2;
gear1_captive_nut_r = gear1_captive_nut_d/2;
gear1_captive_nut_h = 3;
// GEAR2 (LARGER GEAR, DRIVE SHAFT GEAR) OPTIONS:
gear2_teeth = 51;
gear2_shaft_d = 13;
gear2_shaft_r = gear2_shaft_d/2;
// gear2 has settable outer shaft diameter.
gear2_shaft_outer_d = 8.1;
gear2_shaft_outer_r = gear2_shaft_outer_d/2;
// gear2 has a hex bolt set in it, is either a hobbed bolt or has the nifty hobbed gear from MBI on it.
gear2_bolt_hex_d = 15;
gear2_bolt_hex_r = gear2_bolt_hex_d/2;
// gear2_bolt_sink: How far down the gear shaft the bolt head sits; measured as distance from drive end of gear.
gear2_bolt_sink = 0;
// 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)
bridge_helper_h=3;
gear2_rim_margin = 8;
gear2_cut_circles = 5;
// gear2 setscrew option; not likely needed.
gear2_setscrew_offset = 0;
gear2_setscrew_d = 0;
gear2_setscrew_r = gear2_setscrew_d/2;
// captive nut for the setscrew
gear2_captive_nut_d = 0;
gear2_captive_nut_r = gear2_captive_nut_d/2;
gear2_captive_nut_h = 0;
// Tolerances for geometry connections.
AT=0.02;
ST=AT*2;
TT=AT/2;
module bridge_helper()
{
difference()
{
translate([0,0,-bridge_helper_h/2])
cylinder(r=gear2_bolt_hex_r+TT, h=bridge_helper_h+TT,$fn=6,center=true);
translate([0,0,-bridge_helper_h/2])
cube([gear2_bolt_hex_d+ST, gear2_shaft_d, bridge_helper_h+AT], center=true);
}
}
module gearsbyteethanddistance(t1=13,t2=51, d=60, teethtwist=1, which=1)
{
cp = 360*d/(t1+t2);
g1twist = 360 * teethtwist / t1;
g2twist = 360 * teethtwist / t2;
g1p_d = t1 * cp / 180;
g2p_d = t2 * cp / 180;
g1p_r = g1p_d/2;
g2p_r = g2p_d/2;
echo(str("Your small ", t1, "-toothed gear will be ", g1p_d, "mm across (plus 1 gear tooth size) (PR=", g1p_r,")"));
echo(str("Your large ", t2, "-toothed gear will be ", g2p_d, "mm across (plus 1 gear tooth size) (PR=", g2p_r,")"));
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."));
echo(str("Your gear mount axles should be ", d,"mm (", g1p_r+g2p_r,"mm calculated) from each other."));
if(which == 1)
{
// GEAR 1
difference()
{
union()
{
translate([0,0,(gear_h/2) - TT])
gear( twist = g1twist,
number_of_teeth=t1,
circular_pitch=cp,
gear_thickness = /*gear_shaft_h +*/ (gear_h/2)+AT,
rim_thickness = (gear_h/2)+AT,
//rim_width = 0,
hub_thickness = (gear_h/2)+AT,
/*hub_width = 0,*/
bore_diameter=0);
translate([0,0,(gear_h/2) + AT])
rotate([180,0,0])
gear( twist = -g1twist,
number_of_teeth=t1,
circular_pitch=cp,
gear_thickness = gear_shaft_h + (gear_h/2)+AT,
rim_thickness = (gear_h/2)+AT,
hub_thickness = (gear_h/2)+AT,
rim_width = 0,
hub_width = 0,
bore_diameter=0);
}
//DIFFERENCE:
//shafthole
translate([0,0,-2*(gear_shaft_h+ST)])
cylinder(r=gear1_shaft_r, h=2*(gear_h+gear_shaft_h+ST));
//setscrew shaft
translate([0,0, (-gear_h/2 - gear_shaft_h/2+gear1_setscrew_offset)])
rotate([0,90,0])
cylinder(r=gear1_setscrew_r, h=g1p_r);
//setscrew captive nut
translate([(g1p_r)/2, 0, -(gear_h+gear_shaft_h-gear1_captive_nut_r-gear1_setscrew_offset)])
translate([0,0,(gear1_captive_nut_r+gear1_setscrew_offset)/2])
cube([gear1_captive_nut_h, gear1_captive_nut_d, gear1_captive_nut_r+gear1_setscrew_offset+ST],center=true);
}
}
else
{
// GEAR 2
difference()
{
union()
{
translate([0,0,(gear_h/2) - TT])
gear( twist = -g2twist,
number_of_teeth=t2,
circular_pitch=cp,
gear_thickness = /*gear_shaft_h +*/(gear_h/2)+AT,
rim_thickness = (gear_h/2)+AT,
rim_width = gear2_rim_margin,
hub_diameter = gear2_shaft_outer_d,
hub_thickness = (gear_h/2)+AT,
bore_diameter=0,
circles = gear2_cut_circles);
translate([0,0,(gear_h/2) + AT])
rotate([180,0,0])
gear( twist = g2twist,
number_of_teeth=t2,
circular_pitch=cp,
gear_thickness = gear_shaft_h +(gear_h/2)+AT,
rim_thickness = (gear_h/2)+AT,
rim_width = gear2_rim_margin,
hub_diameter = gear2_shaft_outer_d,
hub_thickness = (gear_h/2)+AT,
bore_diameter=0,
circles = gear2_cut_circles);
}
//DIFFERENCE:
//shafthole
translate([0,0,-gear_h-TT])
cylinder(r=gear2_shaft_r, h=2*(gear_h+gear_shaft_h+ST));
//setscrew shaft
translate([0,0,gear_h+gear_shaft_h-gear2_setscrew_offset])
rotate([0,90,0])
cylinder(r=gear2_setscrew_r, h=gear2_shaft_outer_d);
//setscrew captive nut
translate([(gear2_shaft_outer_d)/2, 0, gear_h+gear_shaft_h-gear2_captive_nut_r-gear2_setscrew_offset])
translate([0,0,(gear2_captive_nut_r+gear2_setscrew_offset)/2])
cube([gear2_captive_nut_h, gear2_captive_nut_d, gear2_captive_nut_r+gear2_setscrew_offset+ST],center=true);
//trim shaft
//difference()
//{
// translate([0,0,gear_h+AT]) cylinder(h=gear_shaft_h+ST, r=g2p_r);
// translate([0,0,gear_h]) cylinder(h=gear_shaft_h, r=gear2_shaft_outer_r);
//}
//hex bolt shaft
translate([0,0,-gear_h-TT])
cylinder(r=gear2_bolt_hex_r, h=gear_h+gear_shaft_h-gear2_bolt_sink+AT,$fn=6);
}
// hex bolt shaft bridge aid.
//translate([0,0,gear_h+gear_shaft_h-gear2_bolt_sink])
// bridge_helper();
//translate([0,0,gear_h+gear_shaft_h-gear2_bolt_sink+bridge_helper_h/3])
// rotate([0,0,60]) bridge_helper();
//translate([0,0,gear_h+gear_shaft_h-gear2_bolt_sink+((bridge_helper_h/3)*2)])
// rotate([0,0,-60]) bridge_helper();
}
}
t1 = gear1_teeth;
t2 = gear2_teeth;
cp = 360*distance_between_axels/(t1+t2);
g1p_d = t1 * cp / 180;
g2p_d = t2 * cp / 180;
g1p_r = g1p_d/2;
g2p_r = g2p_d/2;
if(generate == 1)
{
gearsbyteethanddistance(t1 = gear1_teeth, t2=gear2_teeth, d=distance_between_axels, which=1);
}
else if(generate == 2)
{
gearsbyteethanddistance(t1 = gear1_teeth, t2=gear2_teeth, d=distance_between_axels, which=2);
}
else
{
translate([-g1p_r,0,0]) rotate([0,0,($t*360/gear1_teeth)]) gearsbyteethanddistance(t1 = gear1_teeth, t2=gear2_teeth, d=distance_between_axels, which=1);
translate([g2p_r,0,0]) rotate([0,0,($t*360/gear2_teeth)*-1]) gearsbyteethanddistance(t1 = gear1_teeth, t2=gear2_teeth, d=distance_between_axels, which=2);
}