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 History of the English WheelSheetmetal has been used for millennia to make gold funereal masks, copper artworks and vessels, and steel armor. However, since local smiths hand-hammered the entire supply of it, the application of sheet metal stock was limited. When at last the water wheel was turning grinding mills, some smart fellow developed the trip hammer for working metal and the lathes for turning wood and metal. From these nice conveniences came "round" parts which were then used to make even rounder parts, like metal bushings and bearings. Once bearings and shafts were reliable, the machine-produced sheetmetal held rough thickness tolerances and a substantial trade was gradually born.Supposedly, at some point a few hundred years ago, a jewelry smith in central Europe (perhaps Silesia) was to have taken the idea of the small rolling mill used at the time for making wire stock, and made a small frame with two rollers on it for planishing sheet. The device spread across Europe, and ultimately found its largest audience in England, where it is called the "Wheel" or "Wheeling Machine". Though used in Germany, Italy, and America to produce some aircraft and auto panels in the 20th century, it was never as popular as it was in England and so some call it the "English " Wheel. My own teacher, an Irishman by the name of Harry Morrow, laughingly called his an "Irish" wheel, and had lots of stories to tell about his years at Rolls Royce and wheeling polished RAF aircraft panels during the War. Designs of popular models and capacitiesMany of the full-sized English machines, such as Edwards, Brown and Boggs, etc. had cast iron frames on the full-sized models (48" throat) , or 4" flame-cut steel plate in the smaller (28" throat) models. Early models of the large cast iron English Wheels had babbett bearings in them, and when set with high pressures, could be a little difficult to push and pull! These heavy cast frames are nice for hard and/or thick materials, such as .090" 2024 T3. Over the years, frames of flame-cut weldments were offered for those needing suitable stiffness, as even cast iron is somewhat flexible. These machines employ frame designs similar to the large riveters, punch presses, and nibbling machines. Recently though, the resurgence of short-run parts for the auto and aircraft markets have brought in a whole crop of lightweight steel tube-framed machines which are reasonably-priced either in plan form or kit-built and are effective on thinner or softer materials, such as .050" 3003 H14.One odd variation on the Wheel is the "roll-a-ball" machine used to form panels into a depression or cavity. The device operates like a pendulum, with a pivot on the ceiling suspending a long (8'-15') arm with a large roller (18") on the end, which is held in a forked trunnion. There is a handle affixed above the ball that the worker grasps, alternately pushing and pulling the roller over the panel. Pressure is increased periodically by lengthening the threaded adjuster in the arm. Parts up to 5' across have been made this way, but the machine seems to be limited to spherical shapes. Yacht builders are even using Wheeling machines with frames made of massive welded steel I-beams (24"X18"X2") in order to form ½" to 1" thicknesses of steel and aluminum plate. Of course, the pressures necessary to form such parts necessitate enormous force to shove them back and forth through the machine, and so they use motorized chain-driven trolleys to move the large plates. One creative fellow in the Northwest chose remnants of a farm tractor for this purpose, having the advantage of multiple transmission speeds- including reverse- for the task! Function and ApplicationsThe operation of the Wheel is analogous to a "silent continuous hammer". Working like a screw jack, pressure is applied from the lower part of the frame with a handwheel or kickwheel. This turns a threaded jackscrew that thrusts against a bearing-mounted roller. This "lower roll" in turn presses the sheet metal against the upper wheel that is bearing mounted to the upper part of the frame. With compression applied to the sheetmetal between the rolling parts, the sheet is now moved back and forth and the subsequent rolling makes tracks on the metal, raising it by stretching. By application of different pressures and tracking patterns, parts of many differing contours may be raised and fit entirely on the Wheel or simply planished after being roughed on either the bag or the air hammer. The Wheel requires no electric or pneumatic power, so when the California Blackouts roll through our neighborhood, we simply fire up the "Colemen" and start wheeling sheetmetal parts.Since the pressure is set manually and since the sheet metal changes thickness during the wheeling process, (remember from prior articles: stretching = larger but thinner panel) the pressure "loosens" as the metal stretches, and must then be reset at some point. And if you must go back and rework a section to get a better fit, you should reset the pressure correctly for that area. If you miss setting the pressure correctly, you can waste time either by working the metal insufficiently with slack pressure or by overworking the metal and marking it from excessive pressure. The Wheel is therefore a "thickness-based" device, like the Pullmax-type machine. People often wonder how the Wheel is best used, or if it is "better" than say, an air hammer, power hammer, or Pullmax-type machine. I daresay that there are times when nothing else will do, and I can also say there are times when I wish I had anything else! There is an old story out of the Grumman plant in NY, during WW2. It seems they had a lot of small and very thin (.025") panels to form and the big Yoder and Pettingell power hammers were way overkill and the Wheels were too slow. They did a little research in the tool industry and ordered up a bunch of air planishing hammers with 18" and 36" throats and then made the parts rapidly for years thereafter. Another story concerns an ideal (though very difficult) application for the Wheel: A damaged Spartan Executive needed a fresh fuselage topskin, 8' long by 35" wide, made of .032" 2024 T3, in polished condition. The craftsman on the job went looking for the "right" way to make it, and asked several different sources for information. One resource replied that the factory originally made them on the power hammer. (Research has shown they were pressed with dies). A skilled power hammer guy said, "too thin and floppy", and a third, who uses both the Wheel and power hammer unexpectedly said, "Heck, that thing looks very hard…. I'd hire you!" Well, the craftsman ended up making it on the Wheel for the reason that since it was so big and floppy, if it was held right and figured right, it would turn out right. The ideal applications are for planishing (smoothing by light pressures), shaping low crowns, and shaping large and/or thin panels. Or for doing polished work. Ultimately however, it is the particular "bent" of the craftsman as to which forming method suits his way of understanding. The Wheel does require organization, patience and deductive reasoning, IE: Go slowly and observe carefully. The limitations with the Wheel are that it is slow to shape panels with lots of crown, and therefore some assistance may be needed by other methods of generating shape, such as in the shrinking or heavy stretching departments. The Wheel will shrink, as I have demonstrated to students many times, but is limited to soft metals. It will shape small or intricate panels, but only those panels having crowns or radii larger that the lower roll has. Otherwise, the panel winds so tightly around the roll that the worker cannot move it. |