Mother's Homemade Tubing Roller
Building a metal tube roller to bend tube for greenhouses and other buildings to save money.
September/October 1980
By the Mother Earth News editors
Beat the cost of custom conduit shaping by building . . .
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If you've already read the backyard greenhouse article on page 80 of this issue, you know that one of the tools required to build the little "sun shed" is a tubing roller. Now such a device—if purchased—could cost you several hundreds of dollars, because it's normally a motor-driven "professionals only" machine.
A roller is used to shape lengths of standard conduit or electrical metallic tubing (EMT) into arcs (rather than merely to form a corner, as is the case with the far more common tube bender) for use in framing, toolmaking, and other kinds of fabrication. On several occasions MOTHER's shop crew has felt a sore need for one of the handy implements . . . so finally they just up and built their own "North Carolina copy", which fills the bill perfectly!
HERE'S HOW IT WORKS
Most store-bought tube-shapers run on electricity. Our version, though, uses a handcrank that not only feeds the conduit through swiftly and easily, but costs nothing to operate. The tool works like this: The bender itself is simply a pair of crosses—each made of two 18-inch long 2 X 4's—that "sandwich" a set of three grooved pulleys and a pair of support blocks. Two of the wheels (those that are in line along the same crosspiece) serve as idlers ... and the third pulley (positioned at one end of the other crosspiece) is the driver.
When the straight conduit is placed between the driver and the left idler, and the crank is turned, the tubing moves along until it contacts the right idler, which forces the pipe to bend slightly (see the photo below) and to continue to bend till the entire section is arced. (This happens, of course, because the driver is positioned close enough to the idlers to force the conduit to bow.)
AND IT'S EASY TO BUILD!
The only tools you'll need in order to make this inexpensive device are a drill with an assortment of bits, a couple of wrenches, and a table saw with adjustable fence and blade height. Start by locating a good piece of 3/4" seasoned oak that's at least 5" wide and 30" in length. (While you're at it, find—or plan to cut from the first board, if it's large enough—another section measuring 3/4-inch X 1 1/2-inch X 12 inches . . . which will become the arm of the turning handle.)
