OpenSCAD source code: Photo lamp cold shoe adapter for a desk lamp

Photo Light Bracket for Desk Lamp Arm.scad

// Photo light mount for desk lamp arm
// Ed Nisley  - KE4ZNU
// 2019-03

/* [Layout Options] */

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

Part = "Mount";           // [LampArm,ShoeSocket,Mount]

/* [Extrusion Parameters] */

ThreadWidth = 0.40;
ThreadThick = 0.25;

HoleWindage = 0.2;

Protrusion = 0.1;

//-----
// Dimensions

/* [Hidden] */

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

/* [Dimensions] */

FrictionDisk = [4.0,16.5,11.0];                       // squashed inside desk lamp arm frame
Divots = [4.0,9.5,0.75];                              // recesses for frame alignment bumps
ArmLength = 30.0;                                     // attached to disk

ShoeWheelOD = 32.0;                                   // lock wheel on photo lamp
ShoeBase = [18.5,18.5,2.0] + [HoleWindage,HoleWindage,2*ThreadWidth];     // square base on photo lamp gimbal
ShoeStem = [6.3,12.0,1.5];                           // top slide clearance, ID = 1/4 inch screw
ShoeBlock = [ShoeWheelOD,ShoeWheelOD,2*(ShoeBase.z + ShoeStem.z)];  // overall shoe block

NumSides = 3*4;

//-----
// Useful routines

function IntegerMultiple(Size,Unit) = Unit * ceil(Size / Unit);

module PolyCyl(Dia,Height,ForceSides=0,Center=false) {			// 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,center=Center);
}


//-----
// Various Parts

// Arm captured in disk lamp

module LampArm() {

  difference() {
    union() {
      cylinder(d=FrictionDisk[OD],h=FrictionDisk[LENGTH],$fn=NumSides,center=true);
      hull()
        for (j=[-1,1])
          translate([0,j*(FrictionDisk[OD]/2 - FrictionDisk[LENGTH]/2),0]) {
            rotate([0,90,0]) rotate(180/NumSides)
              cylinder(d=FrictionDisk[LENGTH]/cos(180/NumSides),h=ArmLength/2,$fn=NumSides);
            translate([ArmLength - FrictionDisk[LENGTH]/2,0,0])
              sphere(d=FrictionDisk[LENGTH],$fn=NumSides);
          }
    }
    rotate(180/6) {
      PolyCyl(FrictionDisk[ID],FrictionDisk[LENGTH] + 2*Protrusion,6,Center=true);
      for (k=[-1,1])
        translate([0,0,k*(FrictionDisk[LENGTH]/2 - Divots[LENGTH]/2)])
          PolyCyl(Divots[OD],Divots[LENGTH] + Protrusion,6,Center=true);
    }
  }
}

// Basic hot shoe socket

module ShoeSocket() {

  difference() {
    union() {
      cube(ShoeBlock,center=true);                                  // overall blocky retainer
      translate([-ShoeBlock.x/2,0,0])
        cylinder(d=ShoeBlock.x,h=ShoeBlock.z,$fn=NumSides,center=true);
    }
    translate([0,0,-2*ShoeBlock.z])                                 // screw hole throughout
      rotate(180/6)
        PolyCyl(ShoeStem[ID],4*ShoeBlock.z,6);
    translate([0,0,ShoeBase.z/2])                                   // base slot under pillar
      cube([ShoeBase.x,ShoeBase.y,ShoeBase.z],center=true);
    translate([ShoeBase.x/2,0,ShoeBase.z/2])                        // base slot opening
      cube([ShoeBase.x,ShoeBase.y,ShoeBase.z],center=true);
    translate([ShoeStem[OD]/2,0,ShoeBase.z/2 + ShoeStem[LENGTH]])     // stem slot
      cube([2*ShoeStem[OD],ShoeStem[OD],2*ShoeStem[LENGTH]],center=true);

  }
}

// Stick parts together

module Mount() {
  rotate([90,0,0])
    LampArm();
  translate([ArmLength + ShoeBlock.x/2 - Protrusion,0,0])
    ShoeSocket();
}

//-----
// Build things

if (Layout == "Build") {
  rotate([0,90,0])
    translate([-(ArmLength + ShoeBlock.x),0,0])
      Mount();
}

if (Layout == "Show")
  if (Part == "LampArm")
    LampArm();
  else if (Part == "ShoeSocket")
    ShoeSocket();
  else if (Part == "Mount")
    Mount();

More details on my blog at https://wp.me/poZKh-88U