OpenSCAD source code: Sheet holder block for laser cutter

Sheet Holder Bracket.scad

// Bracket for sheet holder
// Ed Nisley KE4ZNU 2022-09-09

Layout = "Show";      // [Show, Build, Blade]

/* [Hidden] */

ThreadThick = 0.25;
ThreadWidth = 0.40;

HoleWindage = 0.2;

Protrusion = 0.1;     // make holes end cleanly

ID = 0;
OD = 1;
LENGTH = 2;

module PolyCyl(Dia,Height,ForceSides=0) {           // based on nophead's polyholes

  Sides = (ForceSides != 0) ? ForceSides : (ceil(Dia) + 2);

  FixDia = Dia / cos(180/Sides);

  cylinder(r=(FixDia + HoleWindage)/2,
           h=Height,
       $fn=Sides);
}


// Sizes

Magnet = [10,30,0.5];   // magnetic sheet size
//Magnet = [10,14,0.5];

MagnetRim = 1.0;

Screw = [3.0,5.5,3.0];  // SHCS OD=head LEN=head

MakerBeam = 10.0;       // beam size, screw = half height
BeamRecess = 0.5;       // slight overhang for alignment

BladeSlot = 0.15 * 4;   // slot with plenty of clearance
BladeSocket = 5.0;      // recess to hold miniblind
BladeWidth = 24.6;      // miniblind width
BladeM = 1.6;           // height of miniblind curve
BladeSides = 12*8;

BladeRadius = (pow(BladeM,2) + pow(BladeWidth,2)/4)/(2*BladeM);
BladeAngle = 2*asin(BladeWidth/(2*BladeRadius));

echo(BladeRadius = BladeRadius);
echo(BladeAngle = BladeAngle);

Block = [Magnet.x + 2*MagnetRim + ceil(BladeRadius*(1 - cos(BladeAngle)) + 2.0),
         Magnet.y + 2*MagnetRim,
         BladeRadius*sin(BladeAngle)];

echo(Block = Block);

// Cutter for spline recess
//  approximately correct and good enough

module BladeRing() {

  rotate([90,0,0])
    translate([0,0,-BladeSocket])
      linear_extrude(height=2*BladeSocket,convexity=2)
        difference() {
          circle(r=BladeRadius,$fn=BladeSides);
          circle(r=BladeRadius - BladeSlot,$fn=BladeSides);
        }

}

// Overall bracket

module Bracket() {

  difference() {
    translate([0,-Block.y/2,0])
      cube(Block,center=false);

    translate([Magnet.x/2 + MagnetRim,0,Block.z - Magnet.z/2 + Protrusion/2])
      cube(Magnet + [0,0,Protrusion],center=true);

    for (j=[-1,1])
      translate([0,j*Block.y/2,MakerBeam/2 - Protrusion/2])
        cube([3*Block.x,2*BeamRecess,MakerBeam + Protrusion],center=true);

    for (j=[-1,1])
      translate([Magnet.x + 2*MagnetRim + BladeRadius,j*Block.y/2,Block.z])
        BladeRing();

    for (j=[-1,1])
      translate([Block.x - 2.0 - BladeSlot,j*Block.y/2,5*ThreadThick/2 - Protrusion/2])
        cube([2*BladeSlot,2*BladeSocket,5*ThreadThick + Protrusion],center=true);

    translate([MakerBeam/2,Block.y,MakerBeam/2])
      rotate([90,0,0])
        PolyCyl(Screw[ID],2*Block.y,6);

    for (j=[-1,1])
      translate([MakerBeam/2,j*(Block.y/2 - Screw[LENGTH] - 1.0),MakerBeam/2])
        rotate([-j*90,0,0])
          PolyCyl(Screw[OD] + HoleWindage,2*Block.y,6);

  }

}

//----------
// Build it

if (Layout == "Blade")
  BladeRing();

if (Layout == "Show")
  Bracket();

if (Layout == "Build")
  Bracket();

More details on [my blog]{https://softsolder.com/) at https://wp.me/poZKh-bi3