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Before You Start Cutting, You Should Consider:  
Maximum Capability vs. Optimum Capability

"Okay.  This brochure says that this new machine has a 12"capacity. Let's haul that 12" chunk of solid stainless over here and see if it'll cut it."  Which makes about as much sense as seeing if that fancy new Volvo station wagon will actually run 145 miles per hour.  Let's talk about the terms "maximum capability" and "optimum capability." 

For each blade size there is an optimum size of material that can be cut:  a size that allows the saw to cut quickly and provide maximum blade life.  This size is determined by the law of physics governing the relationship between the guide spacing and the beam stiffness of the blade.  Anyone interested in the theoretical aspects will find them discussed in the section concerning "Beam Deflection" in any good engineering handbook.  There's a formula for this, which includes things like blade deflection, modulus of elasticity, moment of inertia, load on blade, and spacing of guides.  What it boils down to is that a one-inch blade is good for cutting material, say 4 to 5 inches wide. This is the "optimum capability".   The optimum size range will give you the maximum blade life that you can expect from a particular size blade.  When cutting in the optimum size range, operators with literally no skill and using poor quality blades will still achieve straight cuts. Working within the "optimum" performance range means that a lot of things can be substantially LESS than optimum and you will still receive high quality parts and high-speed production. 

So let's go back to our 12" saw and the plan to cut that chunk of solid stainless.  The saw has a one-inch blade. You better find a real gnarly tooth blade to put on the saw. You'd also better have top quality, properly mixed coolant. You better have an operator who knows the difference between grinding and cutting. And, by the way, the saw needs to be in perfect running order. And you'd better bring your lunch, because this is going to take a while. The blade sets the limit as to the size of material that can be cut.  These are the laws of physics, not the arbitrary rules of any manufacturer. The size and quality of the saw, of course, determines how well the blade is controlled, how much tension can be applied, and how well it is held in alignment as it cuts.  So within the outside limits set by the blade dimensions, the design of the saw is extremely important.  A high-quality one inch machine will easily out-perform a poor quality l 1/ 2 inch machine.  But even the best quality machine cannot cut efficiently if the blade is 

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But even the best quality machine cannot cut efficiently if the blade is attempting to cut through a larger piece of material than the laws of physics permit. That is why different size saws are made. The optimum size gives you accurate parts, excellent blade life, and high production rates. 

When your saw is being run in the “economic maximum" size range, you would expect to reduce the blade life and cutting speed by up to 50 percent. This may be a very sound operating range if not used too frequently. The "design maximum" is the absolute maximum size the saw will handle.  A highly-skilled operator using high quality blades and operating under optimum conditions can expect these results:  long cutting times and poor blade life.  When driving one of those fancy new Volvo station wagons at 145 miles per hour you can expect the following results: long periods of time in jail and short life expectancy.  A short table below will give you an idea of the capabilities of a few selected HE&M Saws.

The same considerations must be made for the feed system. Many factors affect the band sawing operations. For example, if a very skilled operator were to control the machine, he might, even under ideal conditions, vary from the "Optimum Capability" closer to the "Design Maximum".  Generally, you will want to select the saw and feed that will be the most productive for your application. Design Maximum is defined as the largest size which the feed system is designed to support, and is as large as will fit into the saw. However, since large bars are frequently not straight and cause concentration of weight at one point, this is not a practical size for frequent use.  Economic Maximum is defined as the largest size that the machine will handle easily. The Optimum is the size material that can be fed easily without regard to surface condition or straightness. As an analogy, if you have a half-ton truck at its Design Maximum, it can carry 4000 pounds or more.  At its Economic Maximum it may carry 2000 pounds, and at its Optimum Capacity it will carry 1000 pounds. Overloaded vehicles, like saws, start hard and stop poorly.

If you have additional questions about this topic, call or e-mail us today.