Zigzag machining on a CNC lathe is so simple
February 14, 2023
In the past, machining a zigzag on a part required an extra operation on the milling machine or the broaching machine. This requires separate setup on additional machines, resulting in additional labor costs (for milling or broaching operators), and of course additional handling, movement, and possible temporary part storage between processes. In addition, the part may require an intermediate cleaning operation prior to zigzag machining.
If you are one of the companies that make sawtooth processing a single operation, you will be pleased to learn that there is now a sawtooth processing razor that can be sawtoothed on a CNC lathe, just like another process. . The razor for sawtooth processing is manufactured by Schwanog and sold in the United States by GST Tool Co., Ltd. (Roselle, Ill.). The tool consists of a replaceable blade and a matching tool holder. The high speed steel insert with TiN coating consists of a quarter circle with six teeth. Only the first or guiding tooth has a complete (finished) tooth profile. On the remaining 5 teeth, the tooth profile is in a decreasing profile.
If you use the zigzag machining of the part as a secondary operation, then with this serrated razor, you can simply use it as another step on the CNC lathe.
At the beginning of the zigzag process, the spindle remains stationary, while the turret walks three times in the Z-axis, forming the first five teeth and the fully formed sixth tooth in a progressive form.
The tool is mounted on the turret of the lathe and forms serrations along the part through a continuous Z-axis stroke. At the beginning of the process, the spindle remains stationary and the tool runs three lanes to progressively form the first five teeth and the sixth tooth of the full shape. The spindle is then indexed to the next tooth position (requires a C axis) where the first five teeth are incrementally formed and the last tooth is completed. One tooth is machined each time the spindle is indexed to the next tooth position and the turret finishes the part stroke. This process continues until the part is indexed over the entire circle and the zigzag is completely formed.
Once the first tooth is fully formed, the spindle indexes the part to the next tooth position and the turret goes through another path to complete the machining of the tooth. Each time the spindle is indexed, a complete tooth is formed. The indexing cycle continues until the part is fully machined to the desired sawtooth shape.
The process is simple and fast. For example, the sawtooth machining of 1045 steel parts can be machined in less than 7 seconds on a conventional CNC lathe with C-axis function. Combining the sawtooth machining operation into a single lathe process simplifies the handling of the part: this operation does not have to be performed on additional machines, avoiding the cleaning of parts between different processes, additional machine setup and operating costs, and additional part handling. The most important point is that the part is fully machined when it leaves the lathe and is ready for cleaning and delivery to the customer.
GST reports that the serrated blade can be sharpened by the end user, but must provide the tool for centering the tool. The removal of the blade is quick and simple as it is fixed with a single screw. Since the toolholder is only an adhesive tool, the sawtooth machining tool can be used on both multi-spindle and C-spindle machines with C-axis function.
