Why do we need a pre-setter? One of my close friends asked me to write an article on the subject. Being in this field for more than 15 years and after meeting thousands of customers, I could realize in India there is a big gap in understanding the need for Tool Presetter.
To understand tool presetting, we need to go back 30-40 years in Indian Machining culture. When we started machining around 1960s, alike others, we initially started with conventional milling machines. However, since the early 1990s awareness of CNC machines started gearing up. In those times, as CNC machines were very expensive, retrofitting of the conventional machine to semi-CNC became a possible alternative, with the belief that it was a better investment to start with. So as operators from the conventional Machines were moved to the Retrofitted CNC machines, although the machine operator practice remained the same – verifying tool and components on machine itself. Operator got advantage of ensuring Tool that is present on the spindle even though the set-up time was high. The productivity from retrofitting machine to conventional was good, so such a tool set-up time was ignored.
Switch to CNC Machines
When exposure to high-speed CNC machines started gearing up in India, entrepreneurs started investing in CNC machines rather than retrofitted machines. With this move, machine operators of retrofitted machining were again moved to CNC machines and so on their practices. Today, the latest CNC machine has all the functions to take Tool-offset automatically, but the operating practice still continues with old traditional culture approach.
The second reason I was told by entreprenuers is that machine operators always feared to measure tools outside the machine, and some companies who invested in conventional and low cost tool pre-setters had internal inaccuracies in the presetters, resulting in the rejection of components. This was further blamed on
- Over-hang tools
- Runout in the Spindle life
- Runout in tool and holder
- Temperature variation and vibrations in shop-floor
Thus, whenever operator sets up the tools with Inaccurate presetter, they could never measure tool precisely. This resulted in inaccuracies on job dimensions. This killed the trust on Tool Presetter.
What is the Need of Tool Presetter?
The market always has myths and rumors spread like wildfire. One of them I could very often hear was “The tool presetter is used only for boring bars”. This is a half-truth that almost killed the Tool Presetter’s Value. Now logically it’s the tool that is always engaged while cutting the part; whether it is a boring bar or End-Mill, the process is the same. If the tool is measured precisely and informed to the machine, we can control the machine and its operation more efficiently.
Today’s machine can produce exactly the same part as the previous one, but the problem occurs in two stages, first with tool set-up and second is tool wear, and this is the culprit, no matter what difference in the tool, it is reflected on the component. If the tool is measured correctly and the difference value is sent to the machine, then “BOOM” machine will produce exactly the same part as before.
Today’s need of the Hour
For machining, Tool needs to be measured and preset in advance. We need to make “Machining Intervention-Free”. As Machine hour rate cost is a fortune today, day-by-day operation cost is going higher, and the final component cost is becoming a new challenge. In this case, machines need to be utilized more efficiently and cost-effectively.
Which presetter should be bought?
Well, again we can go back 10-15 years, because tool presetters were priced high, we invested in cheap tool presetter and got a bitter experience. Again we tried to blame the presetter.
We need to realize, India is a tropical country and most of our shop floors are not temperature controlled. It is not like European companies where controlling temp is easier; they can drop down the temp using the heater or thermostats. Hence, we need to decide on a Tool presetter that is suitable for Indian manufacturing conditions.
The cost of tool presetter is not justified
Well let’s go back again. In the old days machine per hour rate was cheap and operator cost and rejection cost were high. Hence it was believed if the operator is busy, the machine is busy – Monitoring Operator and his performance meant Productivity. However, today the machine cost is higher than the operator cost. Perhaps, it’s worth having operator idle, but we can’t afford an idle machine. We can track machine performance in the absence of operators. Hence, we need to change the approach. Machine should be busy not operator, it has to be utilized efficiently. Hence, Operator cost will be less than Rs.100, the machine cost will be more that Rs.1000. What is expensive?
Let me elaborate,
Let us assume that a Company A has 10 machines with no presetter. They want to add 20% productivity, there are two situations,
They need to invest on 2 more Machines and add 6 operators (3 operators per shift of 8 hours working) additional space, electricity , toolings and accessories.
They invest in Tool presetter that guarantees 20% saving, i.e out of 10 machines 2 machines will get free. Assuming one machine costs Rs. 20 lacs, the amount saved is Rs.40 lacs. In addition, operator cost reduces, efficiency increases, less Tool costs and above all space is saved.
Conclusion
More importantly, we need to look at operation cost and not operator cost. We are unable to offer good price to our customer because of our inefficiency. We can correct this and can be more competitive.
