Prepierced Hole
Definition
 | This command allows to define a starting point for a cycle(especially pocket cycles) by selecting a pre-defined hole. |
Pocket cycles are built with complex algorithms to deal with the various entities in a selection( stock, pockets, islands, and their parameters, etc.). As such, the starting point of the cycle is handled by the software itself and this may not be ideal for the user.
In order to force the starting point to a desirable location, the Prepierced Hole command comes into play. It is crucial to first define a hole and carry out its drilling operation before using this command.
For instance, for a flat-end mill, the cutting part is on its side but on defining a pocket, the tool may have to start vertically, hence having the bottom of the tool in contact first with the stock and causing undesirable stresses on the tool. Starting at the drilled hole, allows the tool to have contact with the stock directly on its cutting side.
There are 2 ways to define a prepierced hole; one being manually and other applying an opelist automatically. For more details on how to define and apply the prepierced hole, click here.
 No-predrill Bottom of tool in contact with stock |  With predrill Bottom of tool not in contact with stock |