Multitasking Machining can Improve Efficiency When Employed Correctly

Let’s understand more about Multi Tasking Machining, need and development keeping the Indian industry in mind.

Introduction
Whenever you visit customers invariably they speak about the machine cost being high, interest cost of investment and duty structure among others. Buyers of machine tools are very conscious of cost of money i.e. interest rates and traditionally look for very high ROI (return on investment) i.e. about 25 to 30% which is far more if we apply internationally acceptable business norms.

As a machine tool seller if we ask the customers – How many days inventory do you maintain?

We generally do not get a clear answer. If we get answer, it is of the order of two to three months or even more. I am sure there are valid reasons for maintaining such levels of inventory. But as the Indian economy has opened out, Indian companies will have to achieve international standards in order to remain in the business. High interest rates kill you when you borrow money for longer periods, but that is not the case for short periods. In high interest rate economies, the trick is to turn around money very fast.

As we all know inventory is divided into three parts – raw material, work-in-process and finished goods. Generally, value of these inventory is an inverted triangle with raw material at the bottom. Sometimes control of inventory is simple and sometimes complex.

We believe that to remain competitive, we must be serious about top heavy inventory i.e. work-in-progress and finished goods. Once we streamline these two, we must also divert to see how to reduce raw material inventory.

In companies where manufacturing is simple i.e few operations to convert raw material to final products in short span, it may be simple to control inventory. However, if there are several operations involved, inventory control is a complex task.

Historically, there are two major systems of manufacturing. If large volume of similar components, set up dedicated machines. Small volumes, batch production , standalone machines . In batch production, determination of Economic Batch size is crucial to optimize the utilization of machines.

Under such competition, efforts are to meet each and every customers demands. This to an extent means that mass production is over. One has to produce large variety in small numbers. To overcome this, one needs very flexible machines which handles large variety of operations and reduce the process time.

Machine tool builders and experts carried out various studies in machine shops and invariably found that material waiting time / nonproductive time amounts to 30-40 % – be it in stores or on shop floors. Only 60-70% of the time, manufacturing process is actually carried out.

Multi-Tasking
Multitasking may be defined as an ability to perform various operations efficiently without manual intervention-combination of – turning and milling operations in one set-up, first to second operation capability unattended.

That means Multitasking Machine which does both Turning and Milling operations must do Turning and Milling operations as efficiently as any specific TURNING and MILLING MACHINE does.

WE have TURN-MILL centers which are essentially turning machines with limited milling capabilities. These machines do not have true milling capabilities because of insufficient spindle clamping power and limited power on milling tool. Turret construction limits power transmission.

Generally in any machining processes , there are invariably minimum two set-up involved. In first set up , at holding area operations / machining cannot be performed. Machines with bar feeders , one can avoid this to some extent. However, sometimes internal operations are required of part off side.

True Multitasking Machine should be able to change over from first to second operation and complete the part without manual intervention. The benefits of multitask machine are clear – one can simplify the manufacturing process and can manufacture only what can be sold thereby drastically reducing top of inventory. This also reduces raw material inventory as one can convert raw material to finished goods at the last minute.

Development of Multi-task Machines
Generally Multi-Task Machines are based on following platforms

• Turning Machine
• Machining Centers

Development From Two Axis Horizontal Lathe

• 2 Axis CNC Lathe + Rotary Tools + C-Axis
• 2 Axis CNC Lathe + Rotary Tools + C-Axis + Y- Axis
• 2 Axis CNC Lathe + Rotary Tools + C-Axis + Y- Axis + B-Axis
• 2-Axis CNC Lathe + Rotary Tools + C-Axis + Y- Axis + B-Axis + ATC+ automation features i.e. gantry loaders, work-piece measurement, tool life monitoring + gauging, in process gauging, post process gauging, feed force monitoring systems, automatic jaw changing etc.

Just in Time – Fiction or Reality
The basic idea of Just-In-Time is rather simple. You reduce your stock of finished parts to an absolute minimum and add value to the part at the latest moment. This should reduce space for inventory and improve cash flow. The final result should be higher profits and be more competitive.

Often Just-In-Time was realised in setting up machines, let it sit still and only turn it on when order came in. We have all realised that cost of frequent set-up of machine or the cost of all un-used machines waiting to be switched on only after order was received, eat into the cost savings we got from zero stock.

To fulfill the basic requirement of Just-In-Time production, which would really allow to reduce stock to minimum, new way of production machine would be required.

Ideal would be combination of Milling Machine and Turning Machine which can be efficiently used as milling or turning machine as and when necessary.

However, the modern Just-In-Time involves much more than only reducing stock. It is a concept where almost all departments are involved.

Ways of Machining
Due to complex movement of the turret in X+Y+B-axis and movement of work-piece through Z1+C1 and Z2+C2, any tool can be brought into multiple angles and positions for machining. One individual turning tool can be used for facing on left spindle and OD turning on other spindle. For example, one live centering drill can be used to make centering operations within the work-piece for axial, radial, angular and off-center.

Possible relative movements between -Tool +Work piece in three linear X+Y+Z and two rotary B+C provides possibilities for 5-axis operations made from bar or chuck clamping. Integrated second spindle-identical but opposite to first spindle allows secondary operation on 6th face.

How Can You Beat Your Competitors?
To beat your competitors, you may consider the following possibilities
Network

• Establish better sales network
• Establish and maintain closer contacts with your customers
• Establish better service.

Product

• Product is of better quality
• Product has more features
• Product suits better customer needs.

Production

• You can easily integrate customers needs
• You have shorter delivery schedules.
• You can produce more cost efficiently.

Therefore to beat your competitor a new type of machines are desirable – Multi Tasking Machines.

Bottle Neck–What Can You Do?
Existing Methods

To keep up with your demands, you often squeeze out machines and even the operators over their limits. But often forget to check if all the requirements are still needed today. Therefore following points must be checked and the following questions should be raised:

• Why don’t we change the drawing to make the part simpler?
• Why are the blank parts made in a such a way that the consequent operations are almost difficult to perform?
• Why don’t we combine several operations onto one tool?
• Are we using speed / feeds up to date?

If we analyse these questions, probably the complete thought process will shift our manufacturing philosophy towards simplified design aspects from process point of view, using combined tools for improving process times productivity possibilities.

The decrease in product life, increased variety of the product and smaller lot sizes, make it very difficult to make decisions for new investment until right solution is in sight.

Ideal would be most flexible machine which can be changed within minutes to be able to adopt any combination of milling and turning operations.

Multi-Tasking

• To increase your competitive edge

Multi-Tasking Definition

• The ability to perform various manufacturing operations
• without manual intervention
• The combination of Turning + Milling Operations in One Set-Up
• First to Second Operation Capability Unattended.

Multi-tasking Benefits

• Ability to perform Turning+Milling operation in one set-up
• Reduced In-Process Inventory
• Reduced In-Process Time
• Reduced Component Lead Time / Part Handling
• Reduce Set-Up Time
• Reduced Floor Space
• Tolerances Minimized as a result of Few Clamping + De-Clamping and Handling
• High Level of Flexibility
• Unattended Operations
• Multiple Job Capability
• Multiple operations can be performed
• Possibility of Angular Machining – Milling / Drilling with combination of “B” Axis.

Summary
Unnecessary: Set-ups / Part Transfer / Inspections / Human Errors /Scrap / Tooling / Fixtures is wastage of time & money.

As the name suggests, Multi-Tasking machine do more than a single machining task in a single setup. Conventionally, most complex parts required multiple setups on multiple machines. Upon examination, the labour cost associated with setup, part transfer and inspection for the additional operations is a waste. These wastages can be eliminated using Multitasking Machines.

BP Poddar, Vice President – Sales + Marketing, FEMCO (Fatty Tuna India Pvt Ltd)

 

 

Image Courtesy: FEMCO