Tag: CNC

The first pass at the box that will eventually hold the GPS+voice interface for the KG-UV3D radio looks like this, from the end that engages the alignment tabs on the bottom of the radio:

The other end has the opening for the TT3’s serial connector to the GPS receiver, a probably too-small hole for the external battery pack cable / helmet cable / PTT cable, and a hole on the side for the radio mic/speaker cables.

The serial connector opening has a built-in support plate that’s the shape shrunken by 5% so it’s easy to punch out. That worked surprisingly well; the line just above the right edge isn’t a break, it’s a stack of Reversal Zits. This version is rectangular; the solid model shows the proper D shape.

The bottom has battery contact recesses and counterbores (if that’s the right term for a molded feature) for the PCB mounting  screws. In retrospect, those holes should be tapping diameter and the screws inserted from the top, through the PCB.

The colors mark individual pieces that get glued together. I can probably reduce the wall thickness on the top & bottom by three threads, which is in the nature of fine tuning. The latch mechanism that holds this affair to the radio is conspicuous by its absence…

The OpenSCAD source code:

// Wouxun KB-UV3D Battery Pack Case
// Ed Nisley KE4ZNU September 2011

include </home/ed/Thing-O-Matic/lib/MCAD/units.scad>
include </home/ed/Thing-O-Matic/Useful Sizes.scad>
include </home/ed/Thing-O-Matic/lib/visibone_colors.scad>

// Layout options

Layout = "Fit";		// Envelope Plate Base Lid Shell Fit Buildx ScrewSupport
								// PlugPlate

//- Extrusion parameters must match reality!
//  Print with +1 shells and 3 solid layers
//  Use 210 C extrusion temperature to improve layer bonding

ThreadThick = 0.33;
ThreadWidth = 2.0 * ThreadThick;

HoleWindage = 0.2;

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

Protrusion = 0.1;			// make holes end cleanly

BuildOffset = 2.0;			// clearance for build layout

//----------------------
//- Case dimensions

CaseOverallHeight = 40;
CaseOverallWidth = 56;
CaseOverallLength = 80.0;

PlateWidthMin = 53.0;			// plate interfacing with radio contacts
PlateWidthMax = 54.5;
PlateLength = 75.0;
PlateThick = IntegerMultiple(2.0,ThreadThick);

ContactWidth = 7.0 + HoleWindage;
ContactLength = 7.0 + HoleWindage;
ContactRecess = 2*ThreadThick;	// recess for contact metal plate
ContactGapX = 10.5;				// X space between contacts
Contact1Y = 53.0;				// offset from base
Contact2Y = 56.5;

BaseWidthInner = PlateWidthMin;
BaseWidthOuter = CaseOverallWidth;
BaseLength = CaseOverallHeight;
BaseThick = 1.0;
BaseWidthTaper = 5.0;

BaseOpeningMax = 42.0;
BaseOpeningMin = 33.0;
BaseOpeningY = 5.25;
BaseOpeningDepth = 2.0;

BaseTabWidth = 6.0;
BaseTabThick = 2.0;
BaseTabGap = 7.0;
BaseTabOC = BaseTabWidth + BaseTabGap;

BaseToothBase = 6.0;
BaseToothTip = 3.0;
BaseToothThick = 2.0;
BaseToothOC = BaseTabOC;

WedgeAngle = atan(BaseWidthTaper/((BaseWidthOuter - BaseWidthInner)/2));
echo(str("Plate & Shell Wedge Angle: ",WedgeAngle));

BaseEndLip = ThreadThick;			// should be 0.25 mm or so
BaseEndWidth = (PlateWidthMin - 3*BaseToothBase - 2*BaseToothTip)/2;
BaseEndAngle = atan((BaseOpeningDepth - BaseEndLip)/BaseOpeningY);

echo(str("Plate End Angle: ",BaseEndAngle));

PCBWidth = 2.00 * inch;
PCBLength = 2.75 * inch;
PCBMargin = Head2_56;
PCBClearBottom = IntegerMultiple(2*Nut2_56Thick,ThreadThick);
PCBHoleDia = Tap2_56;
PCBHoleY = 2.50 * inch;
PCBHoleX = 1.75 * inch;

echo(str("PCB Mounting Holes OC X: ",PCBHoleX," Y: ",PCBHoleY));
echo(str("       bottom clearance: ",PCBClearBottom));

ShellHeight = CaseOverallHeight - PlateThick;
ShellWidth = CaseOverallWidth;
ShellLength = PlateLength;
ShellWallX = IntegerMultiple((ShellWidth - PCBWidth)/2,ThreadWidth);
ShellWallY = IntegerMultiple((ShellLength - PCBLength)/2,ThreadWidth);
ShellWallMax = max(ShellWallX,ShellWallY);

echo(str("Wall thick X: ",ShellWallX," Y: ",ShellWallY));

LidThick = IntegerMultiple(1.0,ThreadThick);
LidMargin = IntegerMultiple(1.0,ThreadWidth);
LidWidth = ShellWidth - 2*LidMargin;
LidLength = ShellLength - 2*LidMargin;

LidScrewHead = Head3_48;
LidScrewTap = Tap3_48;
LidScrewClear = Clear3_48;
LidScrewLength = 5.0;
LidScrewOffsetX = ShellWidth/2 - LidMargin - 0.75*LidScrewHead;
LidScrewOffsetY = ShellLength/2 - LidMargin - 0.75*LidScrewHead;

HTCableDia = 5.0;
HTCableAspect = 2.0;			// width of hole
HTCableY = 65;
HTCableZ = 10;

SerialZ = ShellHeight - LidThick - 12.0;

BikeCableDia = 5.0;
BikeCableAspect = 1.5;
BikeCableX = -20;
BikeCableZ = 15;

JackOC = 11.20;						// 14.25 OD - (3.58 + 2.58)/2

JackScrewDia = 4.6;
JackScrewOffsetX = 1.00;
JackScrewOffsetY = 5.25;				//  mounting screw to edge of lower recess

PlugBaseWidth = 9.25;				// lower section of plate
PlugBaseLength = 22.0;
PlugBaseThick = 2.5;
PlugBaseRadius = 1.75;

Plug3Offset = 5.25;					// edge of base recess to 3.5 mm jack

Plug2BezelDia = 7.1;				// 2.5 mm plug
Plug2BezelThick = 1.04;
Plug2ScrewDia = 6.0;
Plug3ScrewLength = 3.0;

Plug3BezelDia = 8.13;				// 3.5 mm plug
Plug3BezelThick = 1.6;
Plug3ScrewDia = 7.95;
Plug3ScrewLength = 4.0;

PlugFillOffsetX = JackScrewOffsetX - 0.5;		// base recess CL to fill CL
PlugFillOffsetY = -10.5;				//  ... to edge of fill plate
PlugFillWidth = 11.0;
PlugFillLength = 34.00;
PlugFillThick = 3.0;
PlugFillRadius1 = 1.5;
PlugFillRadius2 = 4.5;

PlugFillOffsetYTotal = 0;

//----------------------
// Useful routines

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);
}

module ShowPegGrid(Space = 10.0,Size = 1.0) {

  Range = floor(50 / Space);

	for (x=[-Range:Range])
	  for (y=[-Range:Range])
		translate([x*Space,y*Space,Size/2])
		  %cube(Size,center=true);

}

//- Hack job for DB-9 (DE-9) panel opening
//  Snug fit around the shell surrounding the male pins
//  DB-9 should mount on outside, but if it's already soldered to the board,
//   that doesn't work and you must mount it inside the box

module DSubMin9(Height=1.0) {

  union() {

	linear_extrude(height=Height,center=false) {
	  hull() {
/*
		translate([-(19.28+0.13)/2,(10.72+0.13)/2,0])			// rectangular outline
		  circle(r=3.05/2,$fn=8);
		translate([-(19.28+0.13)/2,-(10.72+0.13)/2,0])
		  circle(r=3.05/2,$fn=8);
		translate([ (19.28+0.13)/2,(10.72+0.13)/2,0])
		  circle(r=3.05/2,$fn=8);
		translate([ (19.28+0.13)/2,-(10.72+0.13)/2,0])
		  circle(r=3.05/2,$fn=8);
*/
		translate([-(17.0+0.05)/2,-(8.48+0.05)/2,0])
		  circle(r=0.105*inch,$fn=8);
		translate([ (17.0+0.05)/2,-(8.48+0.05)/2,0])
		  circle(r=0.105*inch,$fn=8);
		translate([ (15.5+0.05)/2, (8.48+0.05)/2,0])
		  circle(r=0.105*inch,$fn=8);
		translate([-(15.5+0.05)/2, (8.48+0.05)/2,0])
		  circle(r=0.105*inch,$fn=8);
	  }
	  hull() {
		translate([-24.99/2,0,0])
		  circle(r=3.05/2,$fn=8);
		translate([ 24.99/2,0,0])
		  circle(r=3.05/2,$fn=8);
	  }
	}
  }

}

//-------------------

//- Overall case outline
//  This defines the mating taper into the radio shell

module CaseEnvelope(Length=1) {

	rotate([90,0,0])
	  linear_extrude(height=Length,center=true,convexity=5)
		polygon(points=[
				  [-BaseWidthOuter/2,BaseLength],
				  [-BaseWidthOuter/2,BaseWidthTaper],
				  [-BaseWidthInner/2,0],
				  [-BaseOpeningMax/2,0],

				  [ BaseOpeningMax/2,0],
				  [ BaseWidthInner/2,0],

				  [ BaseWidthOuter/2,BaseWidthTaper],

				  [ BaseWidthOuter/2,BaseLength]
				],
				convexity=1
		);

}

//- Battery contact plate recess
//  This gets subtracted from the bottom plate in two places

module Contact() {

  union() {
	translate([0,0,-(ContactRecess - Protrusion)/2])
	  cube([ContactWidth,ContactLength,(ContactRecess + Protrusion)],center=true);
	translate([0,0,-(PlateThick + Protrusion)])
	PolyCyl(Clear3_48,(PlateThick + 2*Protrusion));
	translate([0,0,-(ContactRecess + Head3_48Thick/3)])
	  PolyCyl(Head3_48,Head3_48Thick);				// allow for solder blob
  }
}

//- Back interface plate with battery contacts

module Plate() {

  difference() {

	translate([0,PlateLength/2,0])
	  intersection() {
		translate([0,0,PlateThick])
		  rotate([180,0,0])
			CaseEnvelope(PlateLength);
	  translate([-PlateWidthMax/2,-PlateLength/2,0])
		cube([PlateWidthMax,PlateLength,PlateThick],center=false);
	  }

	translate([-(ContactGapX/2 + ContactWidth/2),(Contact1Y + ContactLength/2),PlateThick])
	  Contact();
	translate([+(ContactGapX/2 + ContactWidth/2),(Contact2Y + ContactLength/2),PlateThick])
	  Contact();

	translate([0,PlateLength/2,0])
	  PCBHoles(PCBHoleDia,PlateThick);

	translate([0,PlateLength/2,(PlateThick - 2*Head2_56Thick/3)])
	  PCBHoles(IntegerMultiple(Head2_56,ThreadWidth),IntegerMultiple(Head2_56Thick,ThreadThick));
  }

}

//- Radio bottom locating feature
//  This polygon gets subtracted from the battery pack base

module RadioBase() {

linear_extrude(height=(BaseOpeningDepth + Protrusion),center=false,convexity=5)
  polygon(points=[
			[-BaseOpeningMax/2,-Protrusion],

			[-BaseOpeningMin/2,BaseOpeningY],
			[-(BaseToothOC/2 + BaseToothBase/2),BaseOpeningY],

			[-(BaseToothOC/2 + BaseToothTip/2),(BaseOpeningY - BaseToothThick)],
			[-(BaseToothOC/2 - BaseToothTip/2),(BaseOpeningY - BaseToothThick)],
			[-(BaseToothOC/2 - BaseToothBase/2),BaseOpeningY],

			[ (BaseToothOC/2 - BaseToothBase/2),BaseOpeningY],
			[ (BaseToothOC/2 - BaseToothTip/2),(BaseOpeningY - BaseToothThick)],
			[ (BaseToothOC/2 + BaseToothTip/2),(BaseOpeningY - BaseToothThick)],
			[ (BaseToothOC/2 + BaseToothBase/2),BaseOpeningY],
			[ BaseOpeningMin/2,BaseOpeningY],

			[ BaseOpeningMax/2,-Protrusion],

			[ (BaseTabOC + BaseTabWidth/2),-Protrusion],
			[ (BaseTabOC + BaseTabWidth/2),BaseTabThick],
			[ (BaseTabOC - BaseTabWidth/2),BaseTabThick],
			[ (BaseTabOC - BaseTabWidth/2),-Protrusion],

			[ BaseTabWidth/2,-Protrusion],
			[ BaseTabWidth/2,BaseTabThick],
			[-BaseTabWidth/2,BaseTabThick],
			[-BaseTabWidth/2,-Protrusion],

			[-(BaseTabOC + BaseTabWidth/2),-Protrusion],
			[-(BaseTabOC + BaseTabWidth/2),BaseTabThick],
			[-(BaseTabOC - BaseTabWidth/2),BaseTabThick],
			[-(BaseTabOC - BaseTabWidth/2),-Protrusion],
		  ],
		  convexity=5
  );
}

//- PCB Mounting Holes

module PCBHoles(HoleDia=PCBHoleDia,Height=1.0) {

  for (x=[-1,1])
	for (y=[-1,1])
	  translate([(x*PCBHoleX/2),
				(y*PCBHoleY/2),
				-Protrusion])
		PolyCyl(HoleDia,(Height + 2*Protrusion));

}

//-- Battery pack base

module Base() {

  difference() {

	translate([0,0,(BaseThick + BaseOpeningDepth)/2])
	  rotate([-90,0,0])
		CaseEnvelope(BaseThick + BaseOpeningDepth);

	translate([0,0,BaseThick])
	  RadioBase();

	translate([(BaseToothOC + BaseTabWidth/2),
			  -(BaseThick + BaseEndLip)/tan(BaseEndAngle),
			  0])
	  rotate([BaseEndAngle,0,0])
		cube([BaseEndWidth,3*BaseOpeningY,BaseOpeningDepth],center=false);

	translate([-(BaseToothOC + BaseTabWidth/2 + BaseEndWidth),
			  -(BaseThick + BaseEndLip)/tan(BaseEndAngle),
			  0])
	  rotate([BaseEndAngle,0,0])
		cube([BaseEndWidth,3*BaseOpeningY,BaseOpeningDepth],center=false);
  }
}

//- Lid

module Lid(WithHoles = false) {

  translate([0,LidLength/2,LidThick/2])
	difference() {
	  cube([LidWidth,LidLength,LidThick],center=true);
	  if (WithHoles) {
		translate([LidScrewOffsetX,LidScrewOffsetY,-(LidThick/2 + Protrusion)])
		  PolyCyl(LidScrewClear,(LidThick + 2*Protrusion));
		translate([-LidScrewOffsetX,-LidScrewOffsetY,-(LidThick/2 + Protrusion)])
		  PolyCyl(LidScrewClear,(LidThick + 2*Protrusion));
	  }
	}
}

//- Lid screw support shape

module LidScrewSupport(WithHole = false) {

  SupportSize = IntegerMultiple(LidScrewHead,ThreadWidth);

  difference() {
	translate([0,0,LidScrewLength/2])
	cube([SupportSize,SupportSize,LidScrewLength],center=true);
	if (WithHole)
	  translate([0,0,-Protrusion])
		PolyCyl(LidScrewTap,(LidScrewLength + 2*Protrusion));
  }

  translate([-SupportSize/2,SupportSize/2,-2*SupportSize])
	rotate([90,0,0])
	  linear_extrude(height=SupportSize,center=false)
		polygon(points=[
				  [0,0],[0,2*SupportSize],[SupportSize,2*SupportSize]]);

}

//- Battery pack shell

module Shell() {

  union() {
	difference() {

	  translate([0,0,-PlateThick])
		intersection() {
		  CaseEnvelope(ShellLength);
		  translate([0,0,(ShellHeight/2 + PlateThick)])
			cube([ShellWidth,ShellLength,ShellHeight],center=true);
		}

	  translate([0,-LidLength/2,(ShellHeight - LidThick)])
		scale([1,1,2])				// ensure clean cut across top
		  Lid(false);

	  translate([0,0,
				((ShellHeight - PCBClearBottom - LidThick + Protrusion)/2 + PCBClearBottom)])
		cube([PCBWidth,PCBLength,
			 (ShellHeight - PCBClearBottom - LidThick + Protrusion)],
			 center=true);

	  render()
		difference() {
		  translate([0,0,ShellHeight/2])
			cube([(PCBWidth - 2*PCBMargin),
				(PCBLength - 2*PCBMargin),
				(ShellHeight + 2*Protrusion)],
				center=true);
		  for (x=[-1,1])
			for (y=[-1,1])
			  translate([(x*PCBHoleX/2),(y*PCBHoleY/2),-Protrusion])
				cylinder(r=PCBMargin,(ShellHeight + 2*Protrusion),$fn=4);
		}

	  PCBHoles(PCBMargin);

	  translate([-(PCBWidth/2 - Protrusion),(HTCableY - PlateLength/2),HTCableZ])
		rotate([0,-90,0])
		  scale([1/HTCableAspect,1,1])
			PolyCyl(HTCableDia,(ShellWallMax + 2*Protrusion),8);

	  translate([BikeCableX,(PCBLength/2 - Protrusion),BikeCableZ])
		rotate([0,90,90])
		  scale([1/BikeCableAspect,1,1])
			PolyCyl(BikeCableDia,(ShellWallMax + 2*Protrusion),8);

	  translate([0,(PCBLength/2 - Protrusion),SerialZ])
		rotate([-90,0,0])
		  DSubMin9(ShellWallMax + 2*Protrusion);

	}

  	translate([0,(PCBLength/2 + ThreadWidth/2),SerialZ])
	  rotate([-90,0,0])
		scale([0.95,0.95,1])
		  DSubMin9(ShellWallY - ThreadWidth);		// thin support plug in hole

  }

}

//- Speaker-Mic plug mounting plate

module PlugPlate() {

  BaseX = PlugBaseWidth/2 - PlugBaseRadius;
  BaseY = PlugBaseLength/2 - PlugBaseRadius;

  difference() {
	union() {
	  linear_extrude(height=PlugBaseThick,center=false,convexity=3)
		hull() {
		  translate([-BaseX,-BaseY,0])
			circle(r=PlugBaseRadius,$fn=8);
		  translate([-BaseX, BaseY,0])
			circle(r=PlugBaseRadius,$fn=8);
		  translate([ BaseX, BaseY,0])
			circle(r=PlugBaseRadius,$fn=8);
		  translate([ BaseX,-BaseY,0])
			circle(r=PlugBaseRadius,$fn=8);
		}

	  translate([PlugFillOffsetX,
				(PlugFillLength/2 - PlugBaseLength/2 + PlugFillOffsetY),
				PlugBaseThick])
		linear_extrude(height=PlugFillThick,center=false,convexity=5)
		  hull() {
			translate([0,-(PlugFillLength/2 - PlugFillRadius2),0])
			  circle(r=PlugFillRadius2,$fn=10);
			translate([-(PlugFillWidth/2 - PlugFillRadius1),-PlugBaseLength/2,0])
			  circle(r=PlugFillRadius1,$fn=8);
			translate([-(PlugFillWidth/2 - PlugFillRadius1),
					  (PlugFillLength/2 - PlugFillRadius1),0])
			  circle(r=PlugFillRadius1,$fn=8);
			translate([(PlugFillWidth/2 - PlugFillRadius1),
					  (PlugFillLength/2 - PlugFillRadius1),0])
			  circle(r=PlugFillRadius1,$fn=8);
			translate([(PlugFillWidth/2 - PlugFillRadius1),-PlugBaseLength/2,0])
			  circle(r=PlugFillRadius1,$fn=8);
		  }
	}

	translate([0,-JackOC/2,-Protrusion])
	  rotate(360/16) {
		PolyCyl(Plug3BezelDia,(Plug3BezelThick + Protrusion),8);
		PolyCyl(Plug3ScrewDia,(PlugBaseThick + PlugFillThick + 2*Protrusion),8);
	  }

	translate([0,+JackOC/2,-Protrusion])
	  rotate(360/16) {
		PolyCyl(Plug2BezelDia,(Plug2BezelThick + Protrusion),8);
		PolyCyl(Plug2ScrewDia,(PlugBaseThick + PlugFillThick + 2*Protrusion),8);
	  }

	translate([JackScrewOffsetX,-(PlugBaseLength/2 + JackScrewOffsetY),0])
	  PolyCyl(JackScrewDia,(PlugBaseThick + PlugFillThick + Protrusion));
  }

}

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

ShowPegGrid();

if (Layout == "Envelope")
  CaseEnvelope(CaseOverallLength);

if (Layout == "Plate")
  Plate();

if (Layout == "Base")
  Base();

if (Layout == "Lid")
  Lid(true);

if (Layout == "ScrewSupport")
  LidScrewSupport(true);

if (Layout == "Shell")
  Shell();

if (Layout == "PlugPlate")
  PlugPlate();

if (Layout == "DSub")
  DSubMin9();

if (Layout == "Fit") {

  translate([0,-PlateLength/2,0]) {

	translate([0,0,PlateThick])
	  rotate([0,180,0])
		color(LOR) Plate();

	rotate([90,0,0])
	  color(DYO) Base();

	translate([0,LidMargin,10 + (CaseOverallHeight - LidThick)])
	  color(MOR) Lid(true);

	translate([0,PlateLength/2,PlateThick])
	    color(MFG) render() Shell();

	translate([-(ShellWidth/2 +10),70,15])
	  rotate([0,-90,0])
		color(DDY) PlugPlate();
  }
}

if (Layout == "Build1") {

  translate([-20,-PlateLength/2,0])
	Plate();

    translate([10,0,0])
	rotate([0,0,-90])
	  Base();

}

if (Layout == "Build2") {

  translate([0,-LidLength/2,0])
	Lid(true);

}

if (Layout == "Build3") {

  translate([-20,0,0])
	Shell();

}

if (Layout == "Build4") {

  translate([0,0,(PlugBaseThick + PlugFillThick)])
	rotate([180,0,0])
	  PlugPlate();

}

The previous iteration of GPS+voice interface boxes came from the Sherline CNC mill, with a considerable amount of huffing & puffing. I got the Thing-O-Matic to simplify that process…

The general idea is to build a box that clips onto the radio in place of the standard battery pack. External power comes into the box and goes directly to the radio’s battery contacts; this will pose a problem with the Wouxun KG-UV3D, because it wants 7.2 V rather than the stepped-up 9 V from the Li-Ion packs I’ve been using. I think a three-wire power cord is in order: +9 V for the interface, +7.2 V for the radio, and common.

The box also interfaces with the radio’s mic and speaker jacks. Last time around, I made a gluing fixture to keep the plugs in alignment while the epoxy cured around the plugs in the plate, but maybe I can simplify that with 3D printing. Plastic will be better in one respect: the shells of the two plugs must be electrically isolated.

This first-pass (*) approximation shows the three tabs on the pack that engage the radio’s base:

A detail of those tabs, as seen from the bottom:

The ICOM IC-Z1A battery pack had a set of slip-in alignment features that held the pack on the radio, so two strips of tape sufficed to hold the interface box in place. Each Wouxun battery pack includes a spring-loaded latching mechanism that engages a pair of ramped tabs on the radio body that hold the pack against the spring-loaded battery contacts. That means I must come up with an actual latch of some sort to oppose the contact springs, but I haven’t figured that out yet.

The solid model, with the plug mounting plate floating beside it, looks like this:

Tomorrow, the solid modeling…

* It’s actually the third printing of the bottom plate with the three tabs and the base plate with the battery contacts. That’s how I figured out the 0. 5% shrinkage thing.

[Update: The sketch with the dimensions emerged from beneath a pile o’ stuff…]