Tooling Principle
As has been stated, once turret lathe is properly tooled, an experienced machinist is not required to operate it. However, skill is required in the proper selection and mounting of tools. In small-lot production it is important that the work be done in the shortest possible time, so that much of the total production time is saved. The production time consists of the following heads :
(a) Set up time.
(b) Work handling time.
(c) Machine handling time.
(d) Cutting time.
Set-up Time. It is the time consumed in setting of tools on the machine. It can be reduced by having all necessary tools in good and readily available condition. For short run jobs a permanent set up of usual tools on the turret is an excellent means of reducing time.
(b) Work-handling Time. It is the time consumed in mounting or removing the work and is largely dependent upon the type of work holding devices. For bar work, this may be reduced to a minimum by having quick means for advancing the stock.
(c) Machine-handling Time. It is the time consumed in bringing the respective tools into the cutting position.
This can be reduced by having the tools in proper sequence and position.
(d) Cutting Time. It is the time consumed in actual operation and can be controlled by the use of proper cutting tools, feeds, and speeds. This time can be saved by having multiple or combined cuts.
In order to have an economic tooling the total production time should be reduced to minimum.