stepper-motor.md

Stepper Motor

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List of Functions

StepperMotorProfile( ... )	create profile
StepperMotor( profile )	generate stepper motor
StepperMotorPanelHole( profile )	generate 2D holes for panel mounting

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StepperMotorProfile( ... )

model		user defined model name
nemaModel	1A	use info from NEMA model (unless overridden)
bodyDiameter	1B	width and depth of the motor
bodyLength	1B	length excluding shafts and cylinders
shaftDiameter	1B	shaft diameter
shaftLength	1B	shaft length
boltProfile	2A	use info from bolt profile (unless overridden)
boltDiameter	2B	bolt diameter
boltLength	2B	bolt length
boltToBoltDistance	✔	distance between bolts
frontCylinder		list [ diameter, height ]
backCylinder		list [ diameter, height ]
flangeThickness		list [ upper height, lower height ]
bodyTaper		taper on body between flanges
overallTaper		taper on motor body
backShaftLength = 0		length of shaft at the back
panelHoleDiameter		size of center hole for panel mounting the motor
return		KVTree profile

StepperMotor( profile )

profile

✔

stepper motor profile to display

StepperMotorPanelHole( profile )

profile

✔

stepper motor profile to generate panel holes for

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Data Structure

type         : "stepper motor"
model        : "Wantai 57BYGH420-2"
nema         : ""
bodyDiameter : 56.4
length       = all          : 77
               body         : 57.6
               bodyOnly     : 56
               frontCylinder: 1.6
               backCylinder : 0
               shaft        : 19.4
               backShaft    : 0
               frontFlange  : 4.8
               backFlange   : 0
shaft        = diameter: 6.35
               length  : 19.4
backShaft    = diameter: 6.35
               length  : 0
bolt         = diameter: 5
               length  : 10
               distance: 47.14
panelHole    : 8.35
frontCylinder= diameter: 38.1
               length  : 1.6
backCylinder = diameter: 0
               length  : 0
taper        = overall: 2.82
               body   : 1   

---

Sample Code

profile1 = StepperMotorProfile( nemaModel="NEMA17" );
PartAndPanel() {
    StepperMotor( profile1 );
    StepperMotorPanelHoles( profile1 );
};

// custom size
// https://www.sparkfun.com/products/13656 ==> Wantai 57BYGH420-2
// https://www.openimpulse.com/blog/wp-content/uploads/wpsc/downloadables/57BYGH420-Stepper-Motor-Datasheet.pdf
profile2 = StepperMotorProfile(
    model           = "Wantai 57BYGH420-2",
    bodyDiameter    = 56.4,
    bodyLength      = 56,
    shaftDiameter   = 6.35,
    shaftLength     = 21-1.6,
    boltDiameter    = 5,
    boltLength      = 10,
    boltDistance    = 47.14,
    frontCylinder   = [ 38.1, 1.6 ], // diameter, height
    flangeThickness = [  4.8,   0 ], // upper, lower
    bodyTaper       = 1 );
translate( [100,0,0] )
PartAndPanel() {
    StepperMotor( profile2 );
    StepperMotorPanelHoles( profile2, enlargeBolt=3 );
};
kvEchoAligned( profile2 );

// with gear, bolts on gear
profile3 = StepperMotorProfile(
    nemaModel     = "NEMA23",
    boltDistance  = 20,
    frontCylinder = [40,20]
);
translate( [200,0,0] )
PartAndPanel() {
    StepperMotor( profile3 );
    StepperMotorPanelHoles( profile3 );
};
    
// with gear, bolts on body, back cylinder and shaft
// bigger panel hole
profile4 = StepperMotorProfile(
    nemaModel          = "NEMA23",
    boltDiameter       = 8,
    boltLength         = 25+8,    // go below frontCylinderLength
    boltDistance       = 38,
    frontCylinder      = [40,25],
    backCylinder       = [40,20],
    panelHoleDiameter  = 40+2,    // larger than frontCylinderDiameter
    backShaftLength    = 20 );
translate( [300,0,0] ) {
    // position to upper flange
    translate( [0,0, kvGet(profile4,"length.frontCylinder")] )
        StepperMotor( profile4 );
    translate( [0,-100,0] ) PanelOnly()
        StepperMotorPanelHoles( profile4 );
}

// position to lower shaft
translate( [400,0,0] ) {
    translate( [0,0,kvGet(profile3,"length.body")] )
        StepperMotor( profile3 );
}

// position to bottom of body, excluding lower cylinder
translate( [500,0,0] ) {
    translate( [0,0,kvGet(profile4,"length.body")-kvGet(profile4,"length.backCylinder")] )
        StepperMotor( profile4 );
}

module PartAndPanel() {
    children(0);
    translate( [0,-100,0] )
        PanelOnly() children(1);
}
module PanelOnly() {
    linear_extrude( 3 )
    difference() {
        square( [60,60], center=true );
        children();
    }
}