Missler, a well known manufacturer of band saws, is now offering many advantages by using GE Fanuc integrated PLCs and OIs in its designs, which use a new technology that power drives two wheels
Missler is a well known manufacturer of band saws.
It has developed a new technology that power drives two wheels.
As a result, a back-cutting tungsten carbide band-saw blade can cut through highly resistant materials, including metals. Transmission of the power needed to drive the blade occurs through a friction-belt acting on the half circumferences of two wheels.
Missler has become the sole supplier of effective and innovative solutions in the band saw market.
Missler is launching a new generation of metal-cutting band saws.
Missler's deb range (340, 410, 540 and 720) now has a "GTI" version which uses the new process to double the power transmitted to a band saw blade.
Traditionally, band saws used one powered wheel to drive the blade, with the other wheel rotating freely, serving as a return pulley and maintaining tension in the band.
The band tension, then, has two functions.
It ensures the rigidity of the blade, providing it with a good cutting geometry, and allows the blade to be friction driven on the half circumference of one motor-driven wheel.
This technique has proved satisfactory to users.
Progressively, the use of blades with tungsten carbide coated teeth has become common for high-speed use.
This has had two major advantages - both the output and the power of the machine can be doubled.
But this is where the traditional system finds its limitations, for even if the power is doubled, the friction drive actually limits the machine's performance. The solution lies in powering both driving wheels and creating a friction surface equal to the full circumference of a wheel.
Any lack of synchronisation between the two wheels, usually caused by manufacturing tolerances in wheel diameter, is easily compensated for.
As both motors are controlled by the same frequency converter, a phenomenon of "slippage" occurs from the motor bearing the greater load to the other.
The load is distributed evenly between the two motors to within a tolerance of about 5%.
The high rigidity of the machine structure, the special mounting of the wheels, centred between two roller bearings, and the use of hollow shaft reducers, provide unequalled performance.
The advantages of the dual powered wheel design are: - an increased productivity of up to 70 % with the same blade due to an increase in power; - a significant decrease in noise levels; - an increase of up to 100% in the working life of the blade.
Three machine configurations are available: - The Standard configuration comes with a VersaMax Micro PLC.
The operator can control bar feed using a control wheel which has a digital counter.
The control panel contains all the keys and handles needed to control the machine during or before the cutting cycle.
The number of cuts can be pre-selected with a programmable counter.
From 1 to 10 repeat forward movements for a length can be programmed with a coding wheel.
A warning light identifies reasons for machine stoppage for problems such as blade breaking, lack of lubricant, end of bar, etc.
- The Intermediate configuration comes with a VersaMax Micro PLC and VersaMax DataPanel operator interface (OI).
This has a numerical positioning device covering all machine functions.
Up to 99 sequences of different lengths and quantities can be programmed. It automatically manages multiple indexing for pieces longer than the bar-feed stroke (up to 999.9mm).
The cutting length can be programmed and the pieces for the first cut automatically positioned.
A back-lit LCD screen provides the operator with clear instructions during programming and clearly indicates reasons for a machine stoppage.
A gauge permanently records the motor load.
- The advanced configuration has a GE Fanuc 90-30 PLC and CIMPLICITY HMI software.
With this version, a touch screen acts as an ergonomically-designed OI combining all controls It provides easy access to complex operations, displaying for the operator only those (virtual) keys which are applicable to the work in hand.
A customisable materials catalogue contains the cutting conditions for each type.
A "shapes" catalogue lets the operator define the sawing section.
The function allows the machine to make automatic corrections to the cutting and feed speeds based on the thermal effect generated by the blade length in contact with the material at a given depth.
During the sawing operation, a control screen traces theoretical and real forward movement curves, the deviations providing an evaluation of the quality and state of the blade.
The "blade management" module automatically adjusts sawing conditions during the running-in period.
It also provides statistics on productivity and blade life.100 programme sequences of quantity/length allow looping to combine overlapping lengths and minimise offcuts.
Most of the sawing machines manufactured in France by Missler are exported.
Consequently, machines may operate thousands of kilometres away, often in very difficult environments.
Metal sawing generates dust and creates vibrations.
Also, electricity power supply can fluctuate due to the use of other machines on the same premises.
Missler therefore must work with partners who can respond to customers anywhere in the world in cases of breakdown or malfunction.
GE Fanuc provides technical support services throughout the world.
Its software and hardware technical support provides advice on the use of products and their operations.
It can also assist with problems of communications between peripheral devices.
The VersaMax Micro is very compact.
This is a significant advantage in linking PLCs to band saws.
All equipment offered by GE Fanuc is designed with open standards guaranteeing connectivity with almost any I/Os available on the market.
