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Thin-Kerf Saw Technology: There are great savings to be made when it comes to economic
machining of wood, composites, plastics and non-ferrous metals. |
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| New Product News |
 CP200/CPF200
Precise sharpening of Carbide and Stellite-tipped circular saw blades
The CP200 and CPF200 are two new grinding machines from Vollmer. Both machines are equipped with four CNC axes, multiprocessor technology, and integrated software programs. The CP200 is designed for top and face grinding of Carbide or Stellite-tipped circular saw blades with different diameters and tooth geometries, whereas the CPF200 is designed for extremely accurate side grinding.
Both the CP200 and CPF200 are outstanding due to their high flexibility, precision, and compact design. Four CNC axes guarantee optimal movement coordination and short grinding times, as well as a high level of precision. Both machines are easy to use and deliver an excellent grinding result, a fact that makes them perfect for the furniture industry and all types of grinding shops.
> See Machine Video
> Read about the CP200/CPF200
Contact us for more information on the Vollmer CP200 & CPF200.
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With every cut of the saw, material is wasted – and with it, money. The higher quality
the raw material, the more important it is to cut down on waste. The key to this lies in
the saw kerf, which needs to be kept as thin as possible while maximizing the cutting
quality. For this, you need extremely thin saw blades.
The development of this technology has come on leaps and bounds in recent years, resulting in first-class cutting quality, minimal dimensional variations, perfect straightness and a long service life. Thin saw blades are particularly useful for making the outer lamellas of multilayered parquets, for example: not only can they get an extra lamella out of the material, they can also save electricity thanks to the lower cutting resistance.
Sturdy and Flexible
How narrow the kerf can be made depends above all on the material to be cut and
the cutting depth. The stability of the blade body and the resulting kerf quality are
mutually coordinated saw parameters, and often have to be precisely adapted to the
job in hand. The blade thickness and consequent stability are influenced by the feed
speed, saw guidance and condition and hardness of the cut material, as well as by the
tooth shape, pitch and geometries. Variable tooth pitches can minimize vibrations, an
effect, which can be reinforced with corresponding tooth geometries. The aim of this
technology is not only to reduce the kerf and hence improve the yield, but also to facilitate subsequent machining stages such as bonding. The thin-kerf approach thus
represents a major efficiency boost.
Perfect Maintenance
The key criteria for successful results - besides a saw blade that is tailor-made for the
purpose - is a continuous feed, perfect guiding of the cut material and above all timely
sharpening of the saw blade.
Here are some points to bear in mind:
• A “perfect” cutting edge - even after re-sharpening - is the basic prerequisite for a long service life and top cutting quality.
CARBIDE-TIPPED CIRCULAR SAWS
To ensure an optimal cutting edge, the saw tooth should not vibrate during re-sharpening. This can only be achieved if the blade clamp is positioned as close as possible to the HW tooth.
• Excessive grinding pressure is also a cause of vibration. To reduce this, a grinding wheel with a 3 mm rim width can be used instead of a 5 mm one.
• If the grinding wheel doesn’t cut easily and you suspect it may be clogged up, open it up with a grindstone (see also V 01/2012). A clogged-up grinding wheel will also lead to increased grinding pressure, and hence possibly to vibrations. Or it may be necessary to clean the cooling lubricant and choose a lower diamond concentration. You may also find a grinding wheel with a coarser grit size or a double rim (e.g. D126/D46) more suitable.
• If vibrations are caused by the expansion slots in the saw blade, special clamping plates can help by “bypassing” the slots. If too large an infeed was selected for regrinding, the grinding pressure will be too high. This leads to vibrations and hence to poor cutting edges. The solution is modern CNC machines with an oscillation grinding facility. That way even higher erosion rates are possible within a single cycle.
 • If the grinding feed is too fast, that will cause vibrations, too. In this case, simply reducing the feed speed will do the trick.
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Modern thin-kerf saws with an “uneven pitch” can lead to problems in old, conventional sharpening machines with hydraulic control systems. Here, there is a risk that the tooth will be incorrectly positioned and hence not properly machined.
STELLITE®-TIPPED BAND AND MINI GANG SAWS
• Stelliting these thin-kerf saws is only worthwhile economically and qualitatively with the plasma technique (see also V 01/2012). For this, the torch must be suitable for the purpose (torch size, nozzle, etc.). The amount of Stellite® must be less than the kerf diameter (0.76 or 0.89 mm). The forming jaws must be absolutely central in relation to the saw; otherwise the grinding pressure will be too high on one side. Resistance-welded teeth cannot be positioned precisely enough and sometimes lack the necessary durability due to the small size of the contact surfaces.
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For face and top grinding, make sure the blade clamp is securely and exactly positioned right against the tooth. The grinding wheel should also cut easily, as this reduces the grinding pressure, so that the tooth stays still. Cooling is important too: there should be no heat transfer via the workpiece.
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During side grinding, the blade clamp should be positioned right up close to the grinding point. The infeed should be distributed over several grinding strokes (oscillation program); the grinding action should take place from bottom to top; and the grinding pressure should be minimized. With regard to the grinding wheel and coolant, the same applies as for grinding HW-tipped circular saw blades.
 STELLITE® is a trademark of the Deloro Stellite
Holdings Corporation |
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