How Quick change tool holder systems improve your profits
A Quick change tool holder, or Quick change tooling, is a modular system that enables tools to be changed very fast on the machine during:
1. Initial part setup
2. Tool change due to tool wear
The system dramatically reduces machine downtime for tool change during setup changes, and for changing worn out inserts during machining. A normal tool is clamped by inserting it in a slot in the turret and tightening screws to hold it firmly. While doing this, care must be taken to seat the holder properly against available butting surfaces. Finally, the tool offsets must be taken by touching the part or taking skin cuts. The whole process can take 5 to 10 minutes.
With a quick change tool holder, you do not clamp the tool directly in the turret. The tool is replaced by an interchangeable cutting unit. You insert the cutting unit into a standardized locking unit. There are different locking units for internal and external tools, and the locking units remain on the turret forever – there is no need to keep removing them for every part. The interface between the units is such that the cutting unit will only sit in a particular position in the locking unit, and will sit accurately every time. Because of the high precision of the coupling and self-centering design, repeatability can be as high as +/- 2 microns for the same cutting unit in the same female receiver. When doing the setup for a new part, you just quickly insert and clamp a new set of cutting units into the appropriate locking units. The tool offsets are pre-determined for each cutting unit, and remain the same every time that you put in the unit. Tool change time is 30 seconds, against 5 to 10 minutes for normal tooling.
Quick change tooling is more important on lathes than machining centers. This is because tool setup is anyway done offline, on pre-setters. You are not bothered so much about the time of changing tools because there is no machine down time involved in this.
Action point
If the lathes on your shop floor have frequent setup changes, think of buying quick change tooling instead of regular tools. The initial capital cost is much more than standard tool holders, but you recover the investment very fast. E.g., if the total tool change time in a setup is half an hour, you do 2 setup changes a day, and your machine costs Rs. 300 per hour, the cost of downtime is Rs. 300 per day, or Rs. 7500 per month.
Text source: Cadem NCyclopedia multimedia CNC training software.
