The Vollmer Loroch TWIN grinding machine

Following the success of two new circular saw blade grinding machines launched by Vollmer last year, the saw blade sharpening specialist has now unveiled the new Loroch TWIN 860, a space-saving concept with a compact 2,000 x 1,250 x 1,980mm footprint that introduces two different grinding processes in a single machine tool. This gives the end user a machine that can process both carbide tipped (TCT) saw blades for the wood, sawmill and metal cutting industries, as well as HSS, saw blades primarily used in the metal cutting sector.

With the introduction of a fifth axis, a vast selection of TCT blades can be processed in addition to the common metal cutting circular saw blades. As with all Loroch machines, the new TWIN 860 machine grinds with the saw blade rotating. In each case, the grinding process consists of a precise, controlled movement of the grinding head and rotation of the saw blade with both axes controlled simultaneously in complete synchronicity.

HSS circular saw blades from 60 to 860mm can be sharpened and re-cut on the new TWIN 860 machine and automated chamfering is possible from diameters of 75mm and above. With HSS saws, the rake and clearance angles can be freely selected and this grinding process also permits the processing of solid carbide saw blades, friction saws and TK or TA saw blades such as carbide or cermet-tipped thin kerf blades with chip guiding notches.

Furthermore, for the sharpening of TCT saw blades from 145 to 700mm dia, the TWIN 860 has a secondary grinding process whereby the tooth to be ground will remain in a stationary position with grinding performed exclusively by the grinding head. The feeding of each tooth is undertaken by the ultra-precise centre drive that intuitively identifies any pitch differences in the saw blade and automatically processes any irregular pitch patterns in the saw blades. In both grinding processes, complete machining is performed with only one DIA or CBN peripheral grinding wheel (14F1) in each case.

The benefits of the new TWIN 860 go far beyond the ability to undertake both fixed position and rotary processing of the HSS and TCT saw blades through its five servo-driven axes and the ability to detect and process different saw blade pitches. The flexibility of the TWIN 860 enables end users to process everything from straight back teeth, peg teeth, friction teeth, curved back teeth with chamfer, solid carbide teeth as well as TK saw blades and tooth shapes that include 301, 302/303, 304, 311.

The multi-purpose machine also has a high angular precision level, which is a benefit of the ultra-stiff machine base that minimises vibration, as well as a powerful blade clamping system — both attributes that enhance surface finishes and edge quality.

Programming is fast and effortless with a user-friendly touchscreen control that provides easily understandable symbols that intuitively direct the operator through the process. To further simplify operation, the TWIN 860 automatically suggests favourable machining data to guide the user. Moreover, grinding wheel mounting is automated to minimise set-up times.

Possible operating errors are also reduced to a minimum. For the machining of HSS circular saws, it is possible to pre-program saw blades to separate the machine programmer from the operator. The operator only has to clamp the respective saw blade, close the door and press start — another feature that minimises operator errors. From a saw blade perspective, the TWIN 860 offers a chamfering angle of 75deg for HSS saws and 145mm for TK and TCT saws with a tooth pitch of 1-40mm on HSS and TK saws and 6-60mm for TCT blades. The machine is capable of processing chamfer/bevel angles up to 45deg and can grind blades with a maximum blade width of 8mm.