The MSA Profiler has the ability to
tilt the grinding head 10°, both left and right, at selected points in the grinding
cycle.
This is achieved by a cam driven with a series of gears
off the amplitude cam(7). The head is actuated via a cam follower and conrod to a worm
style rack sliding inside the motor arm. This engages a gear segment connected to the
grinding head. The connection between the gear segment and the grinding head relies on the
tightness of the 8mm retaining bolt to “sandwich” all the components. The driver
gear train and cam may be disengaged by moving the idler gear (B36) down its slot. See
Fig. 23. This reverts the machine to perform standard, straight grinding.
Generally it is preferable to angle the backs of the
set teeth away from the centreline to increase the shear angle at the outside edge as
shown in (dia.7b) This produces a more substantial tooth form which holds an edge longer
and is less liable to brittle fracture than standard, flat ground teeth (dia.7a),
Additionally this bevel form tracks straighter and is less sensitive to setting errors.
Another option which works well in soft, fibrous woods
is to apply a positive angle across the front face of the set teeth, section view
(Fig.22c) & plan (Fig.22d), giving the set teeth a very keen outside edge to better
sever the wood fibres. This option does not hold its edge as long as (fig.22b).
