In order to make convincingly round rings, a bending jig is used. How does one make a convincingly round bending jig? With a ring roller, naturally. Why not just use the ring roller to make the rings directly? If you have to ask…

Ring roller, hand cranked.

The rings are 15″ in diameter, measured across the inside edges, so I rolled a 15″ ring as measured from the outside edges to serve as the guide for bending the forged bars into rings. A section of this jig ring was cut down to roughly a semicircle, and welded down to my metal tabletop.

Before I can bend the bars, however, one detail must be attended to; where the ends of the bars meet, I used an offset on one end and a rivet to connect them. I like the simplicity and look of this approach as opposed to welding/grinding. Here is a quick way to put a clean and fairly precise offset in the bar. You can see examples of this technique in some of the pieces in the Gallery section of this site.

The dies are fitted with collars to which plates of the same thickness as the material to be offset are welded.

The material is laid lengthwise on the lower die, and a couple quick blows create crisp, precise bends.

I did not document this process very well, so it may be a little hard to see what happens here. It should be more clear soon.

Now for the bending. It must be done in sections, due to the limitations imposed by the size of my forge. Each ring required four or five heats and bends.

This bar is on it's second heat. The workpiece is clamped to the jig, which is welded to the table. The tool on the right I am working with my right hand. It gives me leverage and can be advanced along the curve of the jig in small increments.

Almost done. Look closely at the end of the bar and you can see the offset coming into the picture.

Drilling the holes for the rivet that closes the rings proved difficult due to the chromoly steel. The heat and compressing forces of the forging process left the steel pretty hard, especially at the surface. I went through several specialty drill bits to get it done. A beefy 3/8″ rivet was used.

Riveted rings are stacking up on the left. Note the offset where the ends are riveted.

The 30 rings which constitute the bulk of the piece were made from custom forged stock. I started with 7/8″ round material and forged it into rectangular flats measuring 1/4″ x 1-1/4″.

Round bar before forging, and after.

I had bought the rounds a couple years earlier from a rancher northwest of Austin who had dismantled some fencing on his land. I bought about 800′ from him, assuming it was just regular mild steel stock. Why would one build a fence with anything else? When I got it back to my shop, I discovered that it was not in fact mild steel, but something more exotic. My best guess is that it is chromoly steel, which is an alloy that contains chromium and molybdenum. It is tough stuff, and can be hardened by heating and quenching. It is good stuff for making tongs and other tools, owing to it’s toughness. For what I paid for it, I got a tremendous deal.

Anyway, I decided to try it out for this piece, given the quantity I was warehousing at my shop. The forging was more difficult, and required higher temperatures to move the steel efficiently. The bars needed to be about 48 inches long. Multiplied by thirty, this was to be a sizable task. To help speed production, and ensure reasonable accuracy, I thought up a little device to facilitate the drawing out process.

Parts used in simple switchable kiss block.

The device is a simple “kiss block” with two sizes available mounted on a jig. As the stock is forged, the blocks are placed between the dies to prevent them from forging the material past the desired dimension. Each end of the rotatable block corresponds in thickness to the two dimensions I want to achieve; in this case, 1/4′ and 1-1/4″. Kiss blocks are sometimes handheld, but this arrangement enabled me to keep both hands on the workpiece; a big help when working long pieces of steel.

While forging the "face" of the bar, the 1/4" end of the block is positioned between the dies.

In a few seconds, the 1-1/4" end of the block can be swung around so that the edge of the bar can be worked.

When the desired dimensions of the bar have been achieved, the block can be swung out of the way to permit planishing (gentle, refining blows). This is done with the bar lying lengthwise to the dies.

This series of posts will document my current work, which I have dubbed the Star Project. It is a forged steel sculpture consisting of thirty rings which connect at twelve points, forming a symmetrical, spheroidal object.

Please note: this first post will be a fairly dry discussion of some formal properties of the sculpture. The process of it’s making will be covered in further posts, and will be of much more interest to the craftsman, blacksmith or metalworker. I will cover several blacksmithing techniques that I have developed which are somewhat unconventional, and there is more to the piece than what I will reveal at first.

Here are a few pictures of an unadorned model of the Star. The rings are made of metal strapping duct taped to wooden dowels. The dowels are stand-ins for more elaborate forms that I will address later. The dimensions of the steel rings will be roughly double those of the model, which are about eight inches in diameter. The overall size of the piece will be about four feet in diameter.

The form is founded on classical geometry. Plato proved the existence of a class of regular polyhedra that consists of five solids; the tetrahedron, cube, octahedron, dodecahedron and icosahedron. These are unique in geometry because they are the only convex polyhedra that can be constructed using only congruent regular polygons. Simply stated, each of the five Platonic Solids are constructed with identical polygons; the tetrahedron is made up of four equilateral triangles, the cube of six squares, the octahedron of eight eq triangles, the dodecahedron of twelve pentagons, and the icosahedron of twenty eq triangles. See the Wiki page for Platonic Solids if this is interesting to you.

The Platonic Solids are fundamental to western math and science, so they are ubiquitous in design, industry and culture. Over the years, my work in sculpture has drawn obliquely from them, though in an intuitive and unfocussed way. I might illustrate this in more detail later. Gradually, however, I began to recognize ways in which the forms I was making related directly to principles governed by the properties of the Platonic Solids.

In this piece I am working with the dodecahedron and the icosahedron (12 and 20 sided polyhedra, respectively). Clearly, my object is not a polyhedron at all, but it is closely related to both. Essentially, I have replaced the thirty edges (straight lines) that constitute an icosahedron with thirty circles, each of which is oriented on a plane that passes through the center point of the object. In doing so, the twelve vertices (points of convergence) of the thirty edges (now circles) of the icosahedron are no longer convex “points” but are recessed within the hypothetical sphere defined by the object’s outermost loci. I warned you this would be dry!

Each of these twelve “vertices” (the bits represented by the dowels in the model) can now be understood as defining the central circle of a torus (doughnut shape in geometry). Each torus is defined by the five rings that converge at each dowel, and each ring is shared by two adjacent tori. Therefore the piece could also be understood as a quasi-dodecahedron, consisting of twelve comingling tori instead of twelve conjoined pentagons.

In actuality, the way that I arrived at this object was through tinkering with tetrahedral models (again, made up of circles, so they were “quasi” tetrahedrons), so the Star could be understood as an assemblage of tetrahedrons.

It is, of course, not at all necessary for the future viewer of the sculpture to know the specifics of what I have just discussed. Everyone has seen countless examples of the various mathematical archetypes I have described. Anyone will instantly recognize that the sculpture is “geometric”. As is apparent in the photos, the piece exhibits varying symmetries depending on the angle of view. Our brains are wired to recognize pattern and symmetry – we have a sort of primordial appreciation of it.

The point of all this is to illustrate how the piece exhibits characteristics of multiple essential “truths” at once, depending on how you choose to define it. By emphasizing one aspect over another, our total understanding can morph into another. This slippage – of perspective, of vision, of understanding – is more important than any particular dissection. This notion flies in the face of the essentialist underpinnings of Plato’s philosophy, which holds that all things can be defined by fixed and unalterable “essences”. This view of the universe, which has for centuries driven and underpinned scientific inquiry, is threatened with obliteration by today’s ideas of the “multiverse”, wherein physical laws and properties are not consistent throughout.