TPT November 2007

C utting, S awing & P rofiling T echnology

A nyone who has used a scroll saw to build a model airplane will be familiar with some of the demands of profiling: turning a blade without snapping it, applying enough pressure but not too much pressure, working to a design that is both a pattern and a set of strict dimensions. Automatic control and repeatability have brought the cutting of a profile to a high degree of refinement. But even in earlier times, the process would not have presented the same kind of challenge as cutting a tube. After all, presuming a hollow section is not meant, a profile is – reassuringly – a solid; whereas a tube is part something and part nothing. Cutting it imposes the necessity of taking account, in one operation, of a solid and a void. Given the choice, a sensible person would prefer to saw through a tree limb. Cutting and sawing of tubulars have benefited enormously from the advance of technology, which permits the application

of special expertise over a range of materials and sizes that widens all the time. A pipette held between thumb and forefinger in a laboratory is not essentially a lesser cutting challenge than an oil transmission pipe which dwarfs the man standing alongside it in a desert. Blade selection. Blade pitch. Blade metallurgy. Rake. Saw tuning. Vice pressure. Coolant application. Band speed. Feed force. Feed pressure. Stack pattern. These are only a few of the factors that determine a perfectly cut or sawn tube, whatever its size or composition or purpose. Fortunately, our industry accesses state-of-the-art technology that accommodates all of them.

The results are no burrs and very little blade wear. This technology has been widely used for cut-off of small gauge stainless tubing. The advances in wheels and process controls have expanded the use of ECG into a variety of applications such as aerospace, automotive, analytic and temperature control equipment, medical and dental devices, surgical tools, catheters, guide wires and body implants. Tube materials such as stainless, high temperature nickel alloys, Nitinol, titanicam, zirconium, and alloy steels are commonly cut using Everite ECG machinery. The Ultracut SR7 is available with programmable automatic feed for high production cutting or manual feed for lower quantities. The machines are now offered in an abrasive version using rubber bond abrasive wheels for applications that can tolerate small burrs.

Electrochemical cut-off machines for burr free tube

True burr free cut-off can easily be achieved on the unique Everite electrochemical tube cut-off machines. By combining the stress- free principles of electrochemical erosion of metals with the precision of abrasive grinding, burr free cuts can be achieved that are fast, clean and completely accurate. Almost any conductive material can be cut effectively with electrochemical grinding

(ECG). Material hardness and machinability have very little impact on cutting speed or blade life. The process is quite simple – low voltage, high current DC power is applied between the conductive grinding wheel (a cathode) and the workpiece (an anode), with an appropriate electrolyte solution flowing to complete the electrochemical process. The material begins to oxidize, allowing the abrasives in the grinding wheel to cut freely with minimal heat and mechanical stress.

fi Everite’s Ultracut SR7 electrochemical tube cut- off machine

Everite Machine Products – USA Fax : +1 215 426 7768 Email : info@everite.net Website : www.everite.net

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N ovember /D ecember 2007