A lathe is a machine used to turn cylindrical surfaces, facing flat surfaces, drilling and boring holes, and cutting external and internal threads. These are typical operations that can be performed consistently and are easily set up. As a lathe, the Smithy can handle small to medium size materials. The standard Smithy unit comes with a three-jaw chuck; a four-jaw chuck for offset turning operations is also available. The primary purpose of a lathe is to turn down or reduce a piece of metal stock to specific dimensions. Photo 4 shows the author's own 1220 XL set up on a specially-built, heavy-duty work table. In this simple example a mild steel rod is being made into an axle for a flea market cart. The shaft is 5/8 inch and the hub for the pneumatic wheels has a bore size of 9/16 inch, a 1/16-inch difference (see Photo 5). The relatively minor reduction of the axle shaft only took a few light passes with cutting tools (Photo 6).
Photo 5 — This is a 5/8 inch diameter steel shaft being used for a flea market cart with the hub on the right. To fit on the hub, some material must be removed from the shaft.
Photo 6 — Steel shaft is placed in the three jaw chuck and the cutting tool is applied to the edge to remove about 0.010 inches of material for each pass of the cutting tool against the shaft. Alignment of the cutting tool is important. It must be perpendicular to the material it is cutting and of the correct angle.
Other more common tasks are centering holes on round stock (Photo7), boring the internal material in large diameter stock (Photo 8), and cutting internal threads. Photos 9 through 16 show a gas cap, a radiator touring cap (or ornament base ring if the center was bored), and cigar lighter parts which were all parts turned on the lathe using various cutters. In the case of the gas cap and radiator base ring, solid brass was chucked in the head first for boring followed by using custom mandrels for further turning and knurling.
Photo 7 — A common task is to use centering bits to bore a hole in the center of some stock chucked up in the lathe's head. The bit is held and moved into the round stock using the 1220 XL tailstock.
Photo 8 — Shown is a set of the centering and countersink drill bits used in Photo 7. A set like this should be included in your basic accessory tools.
Photo 9 — A boring bar is cutting the inside of thick wall tubing. Note that the lathe head must spin in reverse to accomplish this task.
Photo 10 — This gas cap is another example of a part machined on the 1220 XL machine. The cap started out as a solid piece of brass, was bored to the appropriate diameter and the threads were cut using small cutters from the Little Machine Shop. The brass mandrel was salvaged from a gas tank and used to mount (thread) the cap and machine the top round. Afterwards, a knurling tool was used to achieve the diamond knurl pattern.