OpenSCAD source code: Mostly Printed CNC Endstop Mounts for Makerbot-style PCBs

MPCNC MB Endstop Mount.scad

// Tour Easy Fairing Endstop Mount for Makerbot PCB
// Ed Nisley KE4ZNU - 2017-11-07

/* [Build Options] */

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

Section = false;               // show internal details

/* [Extrusion] */

ThreadThick = 0.25;       // [0.20, 0.25]
ThreadWidth = 0.40;       // [0.40]

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

/* [Hidden] */

Protrusion = 0.01;        // [0.01, 0.1]

HoleWindage = 0.2;

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

/* [Sizes] */

RailOD = 23.5;

Screw = [3.4,6.8,8.0];                  // thread dia, head OD, screw length

HoleOffset = [2.5,19.0/2];              // PCB mounting holes from PCB edge, rail center

SwitchClear = [6.0,15,3.0];             // clearance around switch pins
SwitchOffset = [6.0,0];                 // center of switch from holes

Strap = [5.5,50,2.0];                   // nylon strap securing block to rail

Block = [16.4,26.0,RailOD/2 + SwitchClear[2] + Strap[2] + 6*ThreadThick];           // basic block shape

//- Adjust hole diameter to make the size come out right

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);
}

//- Shapes

module PCBBlock() {
  difference() {
    cube(Block,center=true);
    translate([(SwitchOffset[0] + HoleOffset[0] - Block[0]/2),SwitchOffset[1],(Block[2] - SwitchClear[2] + Protrusion)/2])
      cube(SwitchClear + [0,0,Protrusion],center=true);
    for (j=[-1,1])
      translate([HoleOffset[0] - Block[0]/2,j*HoleOffset[1],(Block[2]/2 - Screw[LENGTH])])
        rotate(180/6)
          if (false)                                          // true = loose fit
            PolyCyl(Screw[ID],Screw[LENGTH] + Protrusion,6);
          else
            cylinder(d=Screw[ID],h=Screw[LENGTH] + Protrusion,$fn=6);
    translate([0,0,Block[2]/2 - SwitchClear[2] - Strap[2]/2 - 3*ThreadThick])
      cube(Strap,center=true);
    if (Section)
      translate([Block[0]/2,0,0])
        cube(Block + [0,2*Protrusion,2*Protrusion],center=true);
  }
}

module Mount() {

  difference() {
    translate([0,0,Block[2]/2])
      PCBBlock();
    rotate([0,90,0])
      cylinder(d=RailOD,h=3*Block[0],center=true);
  }

}

//- Build things

if (Layout == "Show") {
  Mount();
  color("Yellow",0.5)
    rotate([0,90,0])
      cylinder(d=RailOD,h=3*Block[0],center=true);
}

if (Layout == "Block")
  PCBBlock();

if (Layout == "Build")
  translate([0,0,Block[2]/2])
  rotate([0,-90,0])
    Mount();

More details on my blog at https://wp.me/poZKh-79B