OpenSCAD source code: Bar clamp mounts for MPCNC

Bar Clamp Mounts.scad

// MPCNC Bar Clamp Mounts
// Ed Nisley KE4ZNU - 2018-02-03

Layout = "Build";         // BarEnd EndBlock ScrewBlock Build

Chirality = "Right";       // bar handedness = side with opening

/* [Extrusion] */

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

/* [Hidden] */

Protrusion = 0.1;        // [0.01, 0.1]

HoleWindage = 0.2;

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

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

//- 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);
}

/* [Clamp] */

BarEndOut = [34.5,21.0];                  // outside dimensions
BarEndIn = [28.0,18.0];                   //  ... inside
BarEndSlot = [2.8,11.5];                  // slot on open side
BarEndRadius = 1.5;                       // corner rounding
NumSides = 3*4;                           //  ... and sides

BarHeightOC = 22.0;                       // min height above bench

Clearance = 0.2;                          // overall bar clearance

PinOffset = [14.0,2.5];                         // clamp hardware pin location
PinOD = 6.5;                              //  ... pin OD

WallThick = 5.0;                          // basic wall & floor thickness

EndBlockSize = [2*PinOffset.x + WallThick,BarEndOut.x + 2*WallThick,BarHeightOC + BarEndOut.y/2];

ScrewBlockSize = [2*PinOffset.x,BarEndOut.x + 2*WallThick,BarHeightOC + BarEndOut.y/2];


//-----
// Define shapes

// Aluminum bar extrusion

module BarEnd(Length = 2.0,Hollow=true) {

  linear_extrude(height=Length,convexity=3)
    offset(delta=Clearance)
      difference() {
        hull()
          for (i=[-1,1], j=[-1,1])
            translate([i*(BarEndOut.x/2 - BarEndRadius),j*(BarEndOut.y/2 - BarEndRadius)])
              circle(r=BarEndRadius,$fn=3*4);       // not related to block corner rounding
        if (Hollow) {
          translate([BarEndOut.x/2 - BarEndIn.x/2 - BarEndSlot.x,0])
            square(BarEndIn,center=true);
          translate([BarEndOut.x/2,0])
            square([BarEndOut.x,BarEndSlot.y],center=true);
        }
      }
}

// Block supporting open end of Bar

module EndBlock() {

  Normal = (Chirality == "Left") ? [0,0,0] : [0,1,0];
  Radius = WallThick;

  mirror(Normal)
    difference() {
      if (true)
        hull() {
          dx = EndBlockSize.x/2 - Radius;
          dy = EndBlockSize.y/2 - Radius;
          for (i=[-1,1],j=[-1,1])
            translate([i*dx,j*dy,EndBlockSize.z - Radius]) {
              sphere(r=Radius,$fn=NumSides);
              cylinder(r=Radius,h=Protrusion,$fn=NumSides);
            }
          for (i=[-1,1],j=[-1,1])
            translate([i*dx,j*dy,0])
              cylinder(r=Radius,h=Protrusion,$fn=NumSides);
        }
      else
        translate([-EndBlockSize.x/2,-EndBlockSize.y/2,0])
          cube(EndBlockSize,center=false);
      translate([EndBlockSize.x/2 - PinOffset.x,0*PinOffset.y,-Protrusion])
        rotate(180/8)
          PolyCyl(PinOD,2*EndBlockSize.z,8);
      translate([EndBlockSize.x/2 - 2*PinOffset.x,0,BarHeightOC])
        rotate([0,90,0]) rotate(-90)
          BarEnd(Length=EndBlockSize.x);
    }
}

// Block supporting screw end of Bar
// Ad-hoc chamfers to clear screw mount castings

module ScrewBlock() {

  Normal = (Chirality == "Left") ? [0,0,0] : [0,1,0];
  Radius = WallThick;

  mirror(Normal)
    difference() {
      if (true)
        hull() {
          dx = ScrewBlockSize.x/2 - Radius;
          dy = ScrewBlockSize.y/2 - Radius;
          for (i=[-1,1],j=[-1,1])
            translate([i*dx,j*dy,ScrewBlockSize.z - Radius]) {
              sphere(r=Radius,$fn=NumSides);
              cylinder(r=Radius,h=Protrusion,$fn=NumSides);
            }
          for (i=[-1,1],j=[-1,1])
            translate([i*dx,j*dy,0])
              cylinder(r=Radius,h=Protrusion,$fn=NumSides);
        }
      else
        translate([0,0,ScrewBlockSize.z/2])
          cube(ScrewBlockSize,center=true);
      translate([0,PinOffset.y,-Protrusion])
        rotate(180/8)
          PolyCyl(PinOD,2*ScrewBlockSize.z,8);
      translate([-ScrewBlockSize.x/2 - Protrusion,0,BarHeightOC])
        rotate([0,90,0]) rotate(-90)
          BarEnd(Length=ScrewBlockSize.x + 2*Protrusion,Hollow=false);
      for (i=[-1,1])
        translate([i*ScrewBlockSize.x/2,ScrewBlockSize.y/2,ScrewBlockSize.z - Protrusion])
          rotate(45)
            cube([sqrt(2)*WallThick,sqrt(2)*WallThick,2*ScrewBlockSize.z],center=true);
    }
}


//-----
// Build things

if (Layout == "BarEnd")
  BarEnd();

if (Layout == "EndBlock")
  EndBlock();

if (Layout == "ScrewBlock")
  ScrewBlock();

if (Layout == "Build") {
  translate([EndBlockSize.z/2,0.6*EndBlockSize.y,EndBlockSize.x/2])
    rotate([0,-90,0])
      EndBlock();
  translate([0,-0.6*ScrewBlockSize.y,0])
    ScrewBlock();
}

More details on my blog at https://wp.me/poZKh-7k9