Everything You Need to Know About Broaching on CNC Lathes
The manufacturing process continues evolving as technology becomes more flexible and affordable. In the case of manufacturing gears, CNC machining allows the ability to perform multiple operations with a single machine, drastically cutting down on cycle time.
Since broaching is a second procedure that still uses conventional methods, many gear makers subcontract broaching services to specialty companies if their manufacturing process requires keyways or splines. As gear manufacturers have to contend with long lead times and lengthy supply chain problems, replacing expensive and time-consuming subcontract work in-house will benefit both the manufacturer and their customers.
Broaching on CNC Lathes
Broaching is a unique manufacturing process since it incorporates the feed into the tool. This effectively transforms it into a collection of single-point cutting tools arranged sequentially.
Similar to the numerous steps of a shaper, a new category of CNC tooling and programming permits broaching to be performed without another operation, thereby significantly increasing controlling quality and decreasing time, space, and expense.
CNC broaching machines have a tool holder or changer system that holds and moves the tool. The machine’s CNC system controls the broach tool’s movement and placement during the machining process.
Application of Broaching on CNC Lathes
Broaching can be performed on CNC milling machines and broaching machines. The majority of CNC applications are performed on lathes as the workpiece can be completed without the need to re-clamp it.
The C-axis is essential to create polygon profiles, such as serrations, squares, and hexagonal and splined shafts. To open one keyway, it is only necessary to use the Z, and the X axes will usually suffice. The chuck of the lathe must be locked since the chuck needs to remain in place as the keyway is made.
Slot Broaching or Rotary Broaching?
For internal square and internal hexagon, and internal gears machining, a different option is to employ the rotary broaching method. The tools for rotary broaching are quick because the entire profile is machinable at one time and not every edge individually, like when using slot broaching.
Broaching tools are also utilized on lathes as well as machines. Because processing can only be completed in one go, the machine’s load is extremely high. The machine is often halted, particularly when it has larger diameters.
Static and Live Broaching Tools
There are both static and driven tools. The best choice is based on the number of keyways/edges teeth and workpieces used monthly.
Up to one thousand items per month static slotting machines are economical for smaller workpieces. But, if the amount of pieces exceeds several thousand each month, the live broaching tool is more efficient and economical.
Static broaching solutions that are extensively used include broaching (slotting) devices with the option of clamping in a cylindrical form and inserts of different sizes, geometries, and tolerances. This technique consists of two parts: the insert and the holder for inserts.
The insert is secured to the holder for the insert with screws. The holder for the insert, typically having a size of 25 mm or 32 millimeters, is then clamped onto the holder for boring bars as well as a VDI boring bar holder with a diameter similar to the CNC lathe.