neotrellis-grid/supports.scad

// this SCAD file defines the support structures for the neotrellis grid. (potentially also bottom case)
// TODO fix mounting hole positions


pcb_size = 60; // the PCB is 60x60mm square
pcb_depth = 7.57; // the PCB is 7.57mm deep, overall (including connector + lEDs)
connector_depth=5.7; // the connector on the bottom of the PCB is 5.8mm thick.
pcb_thickness= 1.7; // the PCB itself (just the board, w/o components) is roughly 1.7mm thick

support_width=5; // width of support structure walls
support_depth=10; // depth of support structure wall
floor_depth = 1; // depth of the bottom floor of the support


tolerance = 0.4; // general tolerance
pcb_tolerance = 2; // tolerance for the size of the PCB

wall_height = (pcb_depth-connector_depth)+4; // height of walls above the top of the supports
wall_width = 5; // width of walls above the top of the supports

cutout_width=25; // width of the cutouts in the support structure, for wires etc
cutout_depth=5; // depth of the cutouts in the support structure

pcbs_wide=2; // how many trellis PCBs are in the grid, width-wise
pcbs_long=4; // how many trellis PCBs are in the grid, length-wise

hole_size = 4; // size of the holes in which the top plate pegs sit
hole_depth = 15; // depth of the holes in which the top plate pegs sit

// load and position the PCB grid as a reference
rotate([180,0,0]) {
    translate([pcb_size/2,-pcb_size/2-pcb_size]) {
        for(x=[0:pcbs_long-1]) {
            for(y=[0:pcbs_wide-1]) {
                translate([pcb_size*x,pcb_size*y,0]) {
                   %import("pcb-single.stl");
                }
            }
        }
    }
}

// translate everything down relative to the PCB reference
translate([0,0,-support_depth-pcb_thickness]) {
    box();
}

// a support unit is the individual box underneath one trellis PCB. no cutouts are included in the module as these differ depending on position.
// if outer is true, an extra tolerance is added 
module support_unit() { 
    // outer box - the size of the overall box
    difference() {
        cube([pcb_size,pcb_size,support_depth]);
        translate([support_width,support_width,floor_depth]) {
            // inner box - cuts a hole in the center of the box to create walls+floor
            cube(
            [pcb_size-(support_width*2),
            pcb_size-(support_width*2),
            support_depth+1.01]);
        }
    }
}

// the whole box. Made into a module for importing into an assembly later, maybe?
module box() {
        // create basic grid of support units
    difference() {
        union() {
            // create large outer box
            translate([-(wall_width+pcb_tolerance),-(wall_width+pcb_tolerance)]) {
                difference() {
                    // outer cube
                    cube(
                    [pcb_size*pcbs_long+(wall_width+pcb_tolerance)*2,
                    pcb_size*pcbs_wide+(wall_width+pcb_tolerance)*2,
                    support_depth+wall_height]);
                    // cutout to make it into a box
                    translate([wall_width+pcb_tolerance/2,wall_width+pcb_tolerance/2]) {
                        cube(
                        [pcb_size*pcbs_long+pcb_tolerance,
                        pcb_size*pcbs_wide+pcb_tolerance,
                        support_depth+wall_height+0.1]);
                    }
                }
            }
            union() {
                // support units for the PCBs
                for(x=[0:pcbs_long-1]) {
                    for(y=[0:pcbs_wide-1]) {
                        translate([pcb_size*x,pcb_size*y,0]) {
                            support_unit();
                        }
                    }
                }
            // filler cubes to fill the tolerance.
            // there is likely a better way to do this, but I don't know it.
            // this is a bodge so I can move onto the next thing and hey,
            // it hopefully works well enough.
                translate([-pcb_tolerance,0,0]) {
                    // widthwise
                    cube([pcb_tolerance+1,pcbs_wide*pcb_size, support_depth]);
                    translate([pcbs_long*pcb_size+pcb_tolerance,0,0])
                        cube([pcb_tolerance+1, pcbs_wide*pcb_size+pcb_tolerance, support_depth]);
                    // lengthwise
                    translate([0,-pcb_tolerance,0])
                        cube([pcbs_long*pcb_size+pcb_tolerance*2, pcb_tolerance+1, support_depth]);
                    translate([0,(pcbs_wide*pcb_size),0])
                        cube([pcbs_long*pcb_size+pcb_tolerance*2, pcb_tolerance+1, support_depth]);
                }
            }
        }
        // add lengthwise internal cutouts
        for(x=[0:pcbs_wide-1]) {
            translate(
                [pcb_size/2, 
                (pcb_size/2-cutout_width/2)+(pcb_size*x),
                support_depth-cutout_depth]) {
                    cube([(pcb_size*(pcbs_long-1)),cutout_width,cutout_depth+1]); 
           }
       }
       // add widthwise internal cutouts
       for(x=[0:pcbs_long-1]) {
           translate(
               [(pcb_size/2-cutout_width/2) + ((pcb_size)*x), 
               pcb_size/2,
               support_depth-cutout_depth]) {
                   cube([cutout_width, pcb_size*(pcbs_wide-1), cutout_depth+1]);
           }
       }
       // add cutout for USB port
       translate(
       [pcb_size*(pcbs_long-1)+wall_width+1+pcb_tolerance,
       pcb_size/2-cutout_width/2+pcb_size,
       support_depth-cutout_depth
       ]) {
           cube([pcb_size, cutout_width, wall_width+pcb_tolerance]);
       }
    // mounting holes for plate
       translate(
       [-wall_width/2-pcb_tolerance/2,
       -wall_width/2-pcb_tolerance/2,
       wall_height+support_depth-hole_depth/2]){
           cube([hole_size,hole_size,hole_depth+0.01], center=true);
       }
       translate(
       [wall_width/2+(pcbs_long*pcb_size)+pcb_tolerance/2,
       -wall_width/2-pcb_tolerance/2,
       wall_height+support_depth-hole_depth/2]){
           cube([hole_size,hole_size,hole_depth+0.01], center=true);
       }
       translate(
       [wall_width/2+(pcbs_long*pcb_size)+pcb_tolerance/2,
       wall_width/2+(pcbs_wide*pcb_size)+pcb_tolerance/2,
       wall_height+support_depth-hole_depth/2]){
           cube([hole_size,hole_size,hole_depth+0.01], center=true);
       }
       translate(
       [-wall_width/2-pcb_tolerance/2,
       wall_width/2+(pcbs_wide*pcb_size)+pcb_tolerance/2,
       wall_height+support_depth-hole_depth/2]){
           cube([hole_size,hole_size,hole_depth+0.01], center=true);
       }
    }
}