TPT July 2016

AR T I C L E

Advanced Machine & Engineering/AMSAW

How to reduce vibration in carbide sawing If the machine does not follow the rules above, there’s not much that can be done by the end user to reduce vibration. Above all else, it’s critical for long term production results that end users purchase a stiff machine with robust design. Additionally, we have found that increasing the feed rate to apply more force to the cut may actually help to stabilise the blade in the cut. Finally, it is important to understand the difference between stabilising and damping, making sure that the machine is equipped with the right components for both. Vibration is the most harmful element in carbide sawing, but other factors, such as resonance, and stabilising and damping components must also be considered in machine design. My next piece will highlight the damaging effect of resonance and what can be done to prevent it, and my final piece will distinguish between stabilising and damping, and how machine designers utilise components to stabilise the blade and control vibration to design machines with the lowest cost- per-cut for the customer.

Figure 4: Vibration mode pattern of the second node diameters typically occur at low rpm and have the most damaging effect

Constraints for the machine designer – the rules of saw design When designing a machine, engineers must consider a series of trade-offs. For example, a circular saw blade is torsionally very stiff, but axially or laterally to the blade plane it is very weak. The following equation describes this rule:

D = diameter H = thickness E = modulus of elasticity k = factor which includes other constants and the clamping ratio

Rule 1

As blades increase in diameter they can cut larger stock sizes. However… Larger blades have larger vibration amplitudes and larger blades are also more expensive to purchase and maintain.

Rule 2

As blades get thicker they become stiffer and vibrate less. However…

Advanced Machine & Engineering | AMSAW – USA 2,500 Latham Street

Thicker blades are heavier and more expensive because they cost more to produce, require more horsepower, and are more difficult to maintain and re-sharpen.

Rockford, IL 61103, USA Website: www.amsaw.com

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J ULY 2016