BCT Supercut - The Fundamentals

The Supercut was designed to enable beginnners to be taught safely.  For example, if the tool is brought into contact with the workpiece with the shank resting horizontally on the toolrest and the shank in line with the lathe's axis, the tool WILL NOT cut.  The illustrations, below, show that in this position, the tool's edge is not in contact with the surface of the workpiece.  Note, in photo below left, that this tool is ALWAYS used in the HORIZONTAL position, parallel to the lathe bed

(Left).  To start the cut, the right hand (outer hand, away from the headstock) is drawn towards the body, angling the shank of the tool across the bed, as shown.  This turns the cutting edge into the workpiece face and cutting is now possible.  NB:  the tool remains in a horizontal position, parallel to the lathe bed.

(Left)  To make a cut "planing" the surface of the workpiece, both hands are drawn towards the body at the same rate such that the cutter traverses the face of the workpiece at a constant angle.  The tool remains in the horizontal position, parallel to the lathe bed.

Our final two photographs in this series, left, show that the key to consistent cutting with the Supercut is maintaining the correct "angle of incidence" between the cutter and the surface of the workpiece.  The photos show that the actual angle of the tool shaft is not the critical factor, since this can be angled relative to the cutter head for operator convenience.  The key feature is that the angle between cutter and workpiece should be constant.  (this can also be seen in the preceding photograph - compare the three photos and you'll see that the angle between head and workpiece is constant throughout, despite the shank having been purposely set at various angles - just to make the point!

These first two shots (right) show the tool starting at the centre of the workpiece and being drawn towards the operator, without varying the angle between the cutting head and the workpiece, thus creating a flat(-ish) surface.  To achieve this, both hands have been drawn back towards the operator's body at the same rate.

Note that the tool is presented in the horizontal position, parallel to the lathe bed, at all times.

This next sequence, left, illustrates the converse of the above, and demonstrates how we use the Supercut to cut flowing curves.

As the rim area of the workpiece is approached, the outer (in this case, right) hand is progressively pushed away from the operator (relative to the inner, left, hand) so that the tip of the tool describes an arc.  This maintains the angle between the cutting head and the cut surface as we cut around the curve and out of the bowl area.

There is a close parallel between this action and the action of "following the cut" with a conventional gouge.  Imagine a bowl gouge with the Supercut cutter perched on the end of the flutes, cutting edge outwards.  The cutting edge of the Superflute would approximate the shape of the cutting edge of the bowl gouge, but continued right round to form a circle.  The action of altering the orientation of the Supercut tool shank is identical to that of swinging the handle of the gouge to keep the cutting edge in contact with the cut surface, with the bevel rubbing.  The Supercut's bevel is the edge of the cutter tip.  The "sting in the tail" of the Supercut is that its action allows the cut to be a shearing cut, much less aggressive than that of the bowl gouge, and hence giving a superior surface finish.