The New Hotness

The anonymous USB camera I used with the stereo zoom microscope not only works with VLC, but also with bCNC, and it has a round PCB with ears:

CNC 3018-Pro - Probe Camera - PCB — CNC 3018-Pro – Probe Camera – PCB

Which suggested putting it in a ball mount for E-Z aiming:

CNC 3018-Pro - Probe Camera - ball mount — CNC 3018-Pro – Probe Camera – ball mount

Black filament snippets serve as alignment pins to hold the ball halves together while they’re getting clamped. They’re epoxied into the upper half of the ball, because who knows when I’ll need to harvest the camera.

The clamp mount descends from the Tour Easy Daytime Running Lights, with more screws and less fancy shaping:

USB Camera - Round PCB Mount - solid model - build — USB Camera – Round PCB Mount – solid model – build

The clamp pieces fit around the ball with four M3 screws providing the clamping force:

USB Camera - Round PCB Mount - solid model sectioned — USB Camera – Round PCB Mount – solid model sectioned

The whole affair sticks onto the Z axis carrier with double-sided foam tape:

CNC 3018-Pro - Probe Camera - alignment — CNC 3018-Pro – Probe Camera – alignment

It barely clears the strut on the -X side of the carriage, although it does stick out over the edge of the chassis.

After the fact, I tucked a closed-cell foam ring between the lens threads and the ball housing to stabilize the lens; the original camera glued the thing in place, but some fiddly alignment & focusing lies ahead:

Alignment mirror - collimation — Alignment mirror – collimation

It’s worth noting that the optical axis of these cheap cameras rarely coincides with the physical central axis of the lens. This one requires a jaunty tilt, although it’s not noticeable in any of the pictures I tried to take.

All in all, this one works just like the probe camera on the MPCNC.

The OpenSCAD source code as a GitHub Gist:

	// CNC 3018-Pro Probe Camera mount for anonymous USB camera
	// Ed Nisley KE4ZNU – August 2019

	Layout = "Show"; // [Show, Build, Ball, Clamp, Bracket, Mount]

	//——-
	//- Extrusion parameters must match reality!
	// Print with 2 shells

	/* [Hidden] */

	ThreadThick = 0.25;
	ThreadWidth = 0.40;

	HoleWindage = 0.2;

	Protrusion = 0.1; // make holes end cleanly

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

	inch = 25.4;

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

	//——-
	// Dimensions

	//– Camera

	PCBThick = 1.2;
	PCBDia = 25.0;

	KeySize = [28.0,8.5,IntegerMultiple(PCBThick,ThreadThick)];
	KeyOffset = [0.0,2.0,0.0];

	KeyRadius = IntegerMultiple(sqrt(pow(KeySize.y – KeyOffset.y,2) + pow(KeySize.x/2,2)),0.01);
	echo(str("Key radius: ",KeyRadius));

	Lens = [14.0,18.0,25.0];

	BallID = PCBDia;
	BallOD = IntegerMultiple(2*KeyRadius,5.0);
	echo(str("Ball OD: ",BallOD));

	WallThick = 3.0;

	CableOD = 3.75;

	NumPins = 3;
	Pin = [1.75,1.8,5.0];

	Screw = [
	3.0,6.8,25.0 // M3 ID=thread, OD=washer, LENGTH=below head
	];

	RoundRadius = IntegerMultiple(Screw[OD]/2,1.0); // corner rounding

	ClampSize = [BallOD + 2WallThick,BallOD + 2WallThick,20.0];
	echo(str("Clamp: ",ClampSize));

	MountSize = [5.0,BallOD,25.0];
	MountClearance = 1.0; // distance between clamp and mount

	Kerf = 2*ThreadThick;

	ScrewOC = [ClampSize.x – 2RoundRadius,ClampSize.y – 2RoundRadius];
	echo(str("Screw OC: ",ScrewOC));

	Insert = [ // brass insert: body, knurl,length
	3.9,4.9,8.0
	];
	UseInsert = false;

	NumSides = 12*4;

	//——-

	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);
	}


	//——-
	// Components

	module CamBall(Section="Both") {

	Offset = (Section == "Both") ? 0 :
	(Section == "Upper") ? BallOD/2 :
	(Section == "Lower") ? -BallOD/2 :
	0;

	render(convexity=4)
	intersection(convexity = 3) {
	difference() {
	sphere(d=BallOD,$fn=NumSides);

	sphere(d=BallID,$fn=NumSides); // interior

	PolyCyl(CableOD,2*BallOD,8); // cable & lens holes
	translate([0,0,-Lens[LENGTH]])
	PolyCyl(Lens[OD],Lens[LENGTH],NumSides);

	translate([0,0,-PCBThick])
	PolyCyl(PCBDia,PCBThick,NumSides);

	translate(KeyOffset + [0,-KeySize.y/2,-PCBThick/2]) // PCB key
	cube(KeySize,center=true);

	for (i=[0:NumPins – 1])
	rotate(i*360/NumPins)
	translate([0,-(BallID + BallOD)/4,-Pin[LENGTH]/2])
	PolyCyl(Pin[OD],Pin[LENGTH],6);
	}
	translate([0,0,Offset])
	cube([BallOD,BallOD,BallOD] + 2*[Protrusion,Protrusion,0],center=true);
	}
	}

	module Clamp(Section="Both") {

	Offset = (Section == "Both") ? 0 :
	(Section == "Upper") ? ClampSize.z/2 :
	(Section == "Lower") ? -ClampSize.z/2 :
	0;

	render(convexity=4)
	intersection() {
	difference() {
	hull()
	for (i=[-1,1], j=[-1,1])
	translate([iScrewOC.x/2,jScrewOC.y/2,0])
	cylinder(r=RoundRadius,h=ClampSize.z,$fn=NumSides,center=true);

	sphere(d=BallOD + 2*HoleWindage,$fn=NumSides); // space around camera ball

	for (i=[-1,1], j=[-1,1]) // screws
	translate([iScrewOC.x/2,jScrewOC.y/2,-ClampSize.z])
	PolyCyl(Screw[ID],2*ClampSize.z,6);

	if (UseInsert)
	for (i=[-1,1], j=[-1,1]) // inserts
	translate([iScrewOC.x/2,jScrewOC.y/2,-(ClampSize.z/2 + Protrusion)])
	PolyCyl(Insert[OD],Insert[LENGTH] + Protrusion,8);

	cube([2ClampSize.x,2ClampSize.y,Kerf],center=true); // clamping gap

	}
	translate([0,0,Offset])
	cube([ClampSize.x,ClampSize.y,ClampSize.z] + 2*[Protrusion,Protrusion,0],center=true);

	}
	}

	module Bracket() {

	translate([ClampSize.x/2 + MountSize.x/2 + MountClearance,0,MountSize.z/2 – ClampSize.z/2])
	cube(MountSize,center=true);

	translate([ClampSize.x/2 + MountClearance/2,0,-(ClampSize.z + Kerf)/4])
	cube([MountClearance + 2*Protrusion,MountSize.y,(ClampSize.z – Kerf)/2],center=true);

	}


	module Mount() {

	union() {
	Clamp("Lower");
	Bracket();
	}

	}



	//——-
	// Build it!

	if (Layout == "Ball")
	CamBall();

	if (Layout == "Clamp")
	Clamp();

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

	if (Layout == "Mount")
	Mount();

	if (Layout == "Show") {
	difference() {
	union() {
	color("Purple")
	Clamp("Upper");
	Mount();
	color("LimeGreen")
	CamBall();
	}
	rotate([0,0,45])
	translate([-ClampSize.x,0,0])
	cube(2*ClampSize,center=true);
	}
	}

	if (Layout == "Build") {
	Gap = 0.6;
	translate([-GapBallOD,GapBallOD,0])
	CamBall("Upper");

	translate([-GapBallOD,-GapBallOD,0])
	rotate([0,180,0])
	CamBall("Lower");

	translate([GapClampSize.x,-GapClampSize.y,ClampSize.z/2])
	rotate([0,180,0])
	Clamp("Upper");

	translate([GapClampSize.x,GapClampSize.y,ClampSize.z/2]) {
	rotate(180)
	Mount();
	}
	}

view raw USB Camera – Round PCB Mount.scad hosted with ❤ by GitHub

The New Hotness

CNC 3018-Pro: Probe Camera Case for Anonymous USB Camera