// 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 = 1 ; // 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 = 8 ;
gear2_shaft_r = gear2_shaft_d / 2 ;
// gear2 has settable outer shaft diameter.
gear2_shaft_outer_d = 18 ;
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 = 3 ;
// 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 = 0 ;
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_h / 2 ) + AT ,
rim_thickness = ( gear_h / 2 ) + AT ,
hub_thickness = ( gear_h / 2 ) + AT ,
bore_diameter = 0 ) ;
}
//DIFFERENCE:
//shafthole
translate ( [ 0 , 0 , - TT ] )
cylinder ( r = gear1_shaft_r , h = gear_h + gear_shaft_h + ST ) ;
//setscrew shaft
translate ( [ 0 , 0 , gear_h + gear_shaft_h - 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_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,-TT])
//cylinder(r=gear2_shaft_r, h=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 , - 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 ) ;
}
