This month we’re going to touch on the basics of using an English wheel for shaping metal. There are a lot of English wheel options available on the market these days—from compact bench-top models to large floor units.
(1) My wheel is a mid-level unit from Baileigh Industrial, model EW-40. (2) Most wheels come with at least an upper wheel and a variety of lower anvil dies. (3) The lower anvil works in conjunction with a large upper wheel.
(4) We’ll first look at the effects of a flat lower anvil. As you can see, both the top and bottom wheels are flat and make full contact across the width of the wheels. (5) The pressure of the larger-diameter upper wheel being exerted upon the smaller-diameter lower wheel causes the sheet metal to contour around the smaller-diameter wheel. (6) The pressure is typically adjustable by either a hand- or foot-operated adjustment wheel. Here you can see the sheet metal starting to curve around the lower wheel. (7) We can take a straight edge and see how the material is curving in the direction the metal was drawn through the wheels.
(8) We can also see that the material stayed flat from left to right because both of the wheels are flat across their width. (9) As the sheet metal is drawn back and forth through the wheel, the wheels need to track left to right and/or right to left across the workpiece. When people first use an English wheel they will typically fight against the wheels and struggle to keep a fluid rhythm. This is something that just requires practice. In the same way pinstripe artists practice pulling lines, you can much the same way practice drawing sheet metal through the English wheel. I’ve taken this sheet and drawn a zigzag pattern across the length of the material, spaced in a 1-inch-wide pattern and half-inch pattern.
(10) Use a layout like this to practice drawing in and out while tracking left to right and back again to develop a rhythm. (11) Next, we’ll try a radiused lower die. Take notice of the narrow contact patch between it and the upper wheel face.
(12) Again, with the same type of motion, draw the material back and forth through the upper and lower wheel. (13/14) With added pressure the material once again begins to shape around the lower wheel. (15) With a straight edge you’ll see the material curving lengthwise again.
(16) However, we will also see the material forming around the radius of the lower die left to right as well. (17) If we draw the material through the wheels again perpendicular to the first draw pattern (18/19), we’ll find the material will begin to take on a lot more shape.
(20/21) With more pressure and more passes through the wheel, it will continue to take more shape. However, the center of the material will stretch to a point that will require some shrinking on the edges of the material. The piece will become stressed by the excessive stretching and will begin to look like a potato chip.
One way to eliminate the potato-chip effect is to shrink the edge of the piece prior to shaping in the wheel. For this we’ll go back to what we learned in past issues. Using a mallet and stump we can begin to put shape to the piece and shrink the edges. (22) We’ll want to choose a lower die with a radius that closely matches the radius of the workpiece. (23) Here we can see after just a few minutes the left side of the piece has started to become smooth in comparison to the untouched right side.
(24) With continued work drawing the piece through the wheel across its radius all the way around, we can achieve a pretty smooth finish. (25) You can see here that the workpiece matches the radius of the lower die, and we have done as much work with this die as we can. (26) If we need to shape the piece further, we would need to go to a tighter radiused lower die. However, for the purposes of this demonstration, you can see we have produced a uniform and smooth raised surface. It’s all been done with a single wooden mallet on the forming stump and a single radius die in the English wheel. That is a lot of shape with minimal tools.
If you try these three exercises, you should have a good understanding of the basics when shaping with an English wheel. Don’t be discouraged if it takes you some time to develop a smooth rhythm. Like most things, it just takes practice. In the next installments of the column we are going to look at making a shaping buck and pattern-making techniques. If you have questions or requests for future issues, send me an email at [email protected] HB