OpenFlexure Microscope OpenSCAD docs

small_gears.scad

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OpenFlexure Microscope: Gears for actuators *
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This is part of the OpenFlexure microscope, an open-source *
microscope and 3-axis translation stage. It gets really good *
precision over a ~10mm range, by using plastic flexure *
mechanisms. *
This file generates a small gear, for motor control. *
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(c) Richard Bowman, January 2016 *
Released under the CERN Open Hardware License *
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module printable_small_gears(ratio=2)

[Source]

module printable_small_gears(ratio=2){
    // check the ratio gives an integer number of teeth
    assert(floor(n_teeth_small_gear(ratio))==n_teeth_small_gear(ratio),"The number of teeth on the small gear is not integer");
    // Calculate the spacing from the gear pitch radius.
    // Add 4mm of clearance
    spacing = small_gear_pitch_radius(ratio) + small_gear_pitch_radius(ratio=2) + 4;
    // x and y gears
    repeat([0, 2*spacing, 0], 2, center=true){
        // 3.15 is a trade off. Firm to push on some printers that print
        // the gears loose. Should be press fit with a small clamp/vice
        // if the printer prints tight. All are then locked with two screws
        // Can be adjusted for printers outside this range.
        small_gear(flat_shaft_w=3.15, ratio=ratio);
    }
    // z gear
    small_gear(flat_shaft_w=3.15, ratio=2);
}