epaper_door_case/batt_18650.scad

// 18650 cell + single-cell holder — dimensional mockup for layout exploration
// Dimensions are typical/guessed; tune before committing to a specific holder.
//
// Module origin: centre of holder footprint in XY, flat bottom at z=0.
// Cell long axis runs along X. Cell protrudes above the cradle body.

/* [18650 Cell] */
CELL_D    = 18.5;   // nominal diameter
CELL_L    = 65.5;   // body length (includes button-top positive terminal)

/* [Single-cell holder body] */
// Typical spring-contact cradle: flat floor, cell half-exposed above.
// Spring on one end adds ~4 mm, thin side walls ~1.25 mm each side.
HLDR_W    = 21.0;   // Y width  (cell dia + 2× side wall)
HLDR_L    = 74.0;   // X length (cell + spring contact allowance)
HLDR_FLOOR =  3.0;  // Z thickness of cradle floor under cell

// Cell centre is at floor thickness + cell radius — bottom of cell sits on floor.
CELL_CZ   = HLDR_FLOOR + CELL_D / 2;

module CELL_18650() {
    color("steelblue", 0.9)
        rotate([0, 90, 0])
            cylinder(d=CELL_D, h=CELL_L, $fn=48);
}

// Origin: XY centre of holder footprint, z=0 at flat bottom face.
module HOLDER_18650() {
    // Cradle floor body (solid block — end contacts not modelled)
    color("dimgray", 0.7)
        translate([-HLDR_L/2, -HLDR_W/2, 0])
            cube([HLDR_L, HLDR_W, HLDR_FLOOR]);
    // Cell sitting on the cradle, centred in XY
    translate([0, 0, CELL_CZ])
        CELL_18650();
}

HOLDER_18650();