The UK subsidiary of German sawing machine manufacturer, KASTO, used its recent open house in Milton Keynes (23rd and 24th February 2012) to stress the need to buy the best blades, even if that means spending more, and to invest in top quality sawing machines to maximise productivity and competitiveness.
In developing the theme, managing director Ernst Wagner used the premise that tooling costs are only three per cent of total manufacturing costs, with the remainder spread across labour, machinery, materials, buildings and administration. Sandvik applies the same breakdown when analysing the use of its cutting tools, Saint-Gobain does similar for its grinding consumables and the three per cent figure is equally applicable to band and circular blades used in metal sawing.
The price of a tool is such a small proportion of the total cost of machining that it is easy for a high-performance cutting tool to bring down overall costs by increasing productivity. In other words, the price of tooling is actually an ineffective place to look for savings. On the contrary, skimping on the quality of consumables can and often does reduce cost effectiveness by lowering cutting speed and therefore output. It also prevents lucrative, lights-out sawing free from operator costs, and negatively impacts quality of cut, with the attendant risk of producing scrap.
Two of the leading bandsaw blade producers, Lenox and Wikus, provided their latest products for demonstration cutting on KASTOtec AC4 machines at the Milton Keynes event. The Lenox Black Armor AlTiN-coated, tungsten carbide tipped (TCT) blade was shown cutting Ti64 on a machine with patented KASTO Performance Cutting (KPC) capability. A Wikus M42 high speed steel, bi-metal blade and a Wikus Futura Premium coated carbide blade from Harrison Saw and Tool were seen cutting 316 stainless steel.
Putting some figures around his cost per cut arguments, Mr Wagner cited the following production example.
Cutting 200 mm diameter tool steel, standard bimetal blades costing £1,000 were needed to produce 3,000 cuts in 1,000 hours. TCT blades to produce the same number of parts cost three times as much but completed the job in 375 hours. After overheads were taken into account, cost per cut was £12.00 using the bi-metal blade and just £5.35
using the TCT blade. The saving amortised the extra cost of buying a top-end KASTOtec bandsaw, rather than a standard model, within five months. After that, the ongoing higher level of productivity is pure additional profit.
Speaking about the KASTOtec AC sawing machine, which can be used with or without KPC but increases output by a further 30 per cent if it is switched on, Mr Wagner pointed out that the machine was designed from the outset to extract maximum benefit from TCT saw blades. It can however be used with standard blades, such as when cutting at a slower speed overnight.
Minimising vibration has been key to higher production rates on these saws. They have a steel / mineral cast composite construction that is six to eight times more vibration-absorbing than cast iron. A powerful main drive acts through a play-free, spur bevel gear delivering 98 per cent of available power directly to the drive wheels. Double bearings on both the driven and idle blade wheels promotes stable, even power flow and allows high band tension, which translates into high accuracy cutting.
Overlaid on this already comprehensive specification is the KPC package, a factory-fitted option that KASTO has developed to improve cutting productivity still further. The focus has been on reducing vibration even more during cutting, which raises accuracy, reduces noise and allows increased band speed and feed rates.
Improvements include redesigned blade guides either side of the cutting area to make them more rigid and better cooled, while two innovative spring-loaded tensioner (Trum) guides suppress vibration on the return side of the blade.
Mr Wagner commented, "You cannot simply take an old style bandsaw, fit a 20 kW motor on it and expect it to raise output.
"It is the combination of all the technology that has gone into our tec / KPC carbide sawing machines, aimed at increasing feeds and speeds while reducing vibration, that allows our machines to deliver such high levels of productivity combined with extended blade life.
"Our own brand of machine control is another important benefit. Together with feedback of key parameters from the machine during sawing, customers can program their machines to run at 100 per cent in the certain knowledge that the machine will be slowed or even stopped automatically in response to altered circumstances such as blade wear or damage, or a hard spot in the material.
"KASTO in the UK is particularly fortunate that key industries here include aerospace and offshore, both of which extensively use exotic alloys. Many stockholders around the country have to cut these materials.
"Our tec machines, with or without KPC, are ideal for processing them and in this high-performance machine category, which has accounted for 80 per cent of our bandsaw sales in recent years, we win the vast majority of orders."
KASTO Ltd, Unit 5, Garamonde Drive,
Wymbush, Milton Keynes, MK8 8DF.
Tel: 01908 571590.
Fax: 01908 566106
Web site: www.kasto.uk.com
Contact: Ernst Wagner, Managing Director