The New Hotness

Ortur YRC-1: Conical Tailstock Centers

A conical (a.k.a. bullnose) center in the tailstock simplifies supporting cylindrical objects:

Ortur Chuck Rotary conical center - installed — Ortur Chuck Rotary conical center – installed

The spring-loaded tailstock bearing has a 5 mm bore. The bullnose rests against a small spacer on its 5 mm shaft to hold it away from the bearing’s mounting screws with some bearing spring compression. I turned the spacer from aluminum rod because lathe work is satisfying, but a printed spacer would work fine.

The bullnose is a cone with steps encouraging the cylinder to sit properly:

Ortur Rotary Conical Center - 10-50mm — Ortur Rotary Conical Center – 10-50mm

With both ends centered, the cylinder sits concentric with the chuck axis:

Ortur Chuck Rotary home switch - jaw position — Ortur Chuck Rotary home switch – jaw position

The chuck grabs the OD and the bullnose supports the ID, so removing crud from both ends is in order.

The bullnose won’t work for a solid rod, so a negative cone = cup center may come in handy:

Ortur Chuck Rotary cup center - installed — Ortur Chuck Rotary cup center – installed

Stipulated: A CO₂ laser will bounce right off a solid aluminum rod. Imagine I chucked up a wood dowel, OK?

A cup center is what remains afteryoinking a bullnose out of a cylinder:

Ortur Rotary Conical Centers - cup — Ortur Rotary Conical Centers – cup

Looks like I did exactly that:

Somewhat surprisingly, the two parts nest perfectly:

Ortur Chuck Rotary conical centers - nested — Ortur Chuck Rotary conical centers – nested

That’s without the shaft installed on the cup, so they won’t sit quite so neatly on the shelf.

Aligning the rotary axis along the laser’s X axis and setting the focus requires attention to detail, but a decent tailstock center makes that effort meaningful.

The OpenSCAD code as a GitHub Gist:

	// Ortur Rotary Conical centers
	// Ed Nisley – KE4ZNU
	// 2025-12-27

	include <BOSL2/std.scad>

	Style = "Bullnose"; // [Build,Cone,Bullnose,Cup,Cone]

	MinDia = 10.0;
	MaxDia = 50.0;

	/* [Hidden] */

	LayerThick = 0.2; // should match slicer thickness

	Ramp = 1.0;

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

	HoleWindage = 0.2;
	Protrusion = 0.1;

	NumSides = 834;
	$fn=NumSides;

	Gap = 5.0;

	WallThick = 2.0;

	TailBearing = [5.0,7.0,10.0]; // tailstock shaft, LENGTH = insert depth

	StepHeight = 2*LayerThick;

	NumSteps = (((MaxDia – MinDia)/2) / Ramp);
	ConeOAH = NumSteps * (Ramp + StepHeight);

	//—–
	// Bullnose shape

	module Bullnose() {

	difference() {
	union()
	for (i = [0:NumSteps – 1])
	up(i*(Ramp + StepHeight)) hull()
	cyl(StepHeight + Protrusion,r=(MaxDia/2 – i*Ramp),anchor=BOTTOM) position(TOP)
	cyl(Ramp,r1=(MaxDia/2 – iRamp),r2=(MaxDia/2 – (i+1)Ramp),anchor=BOTTOM);
	}


	}

	module Cone() {

	difference() {
	Bullnose();
	down(Protrusion)
	cyl(TailBearing[LENGTH] + Protrusion,d=TailBearing[ID],circum=true,anchor=BOTTOM);
	}

	}

	module Cup() {

	difference() {
	cyl(ConeOAH + TailBearing[LENGTH],d=MaxDia + 2*WallThick,anchor=BOTTOM);
	up(ConeOAH + TailBearing[LENGTH] + Protrusion)
	yrot(180)
	Bullnose();
	down(Protrusion)
	cyl(TailBearing[LENGTH] + 2*Protrusion,d=TailBearing[ID],circum=true,anchor=BOTTOM);
	}


	}


	//—–
	// Build things

	if (Style == "Bullnose")
	Bullnose();

	if (Style == "Cone")
	Cone();

	if (Style == "Cup")
	Cup();

	if (Style == "Build") {
	right(MaxDia/2 + Gap)
	Cone();
	left(MaxDia/2 + WallThick + Gap)
	Cup();
	}

view raw Ortur Rotary Conical Centers.scad hosted with ❤ by GitHub

2025-12-30