BASIC WOODTURNING
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KNOWING WHEN TO CUT AND WHEN TO
SCRAPE
There are two different approaches to the
work when turning. The first is towards a
circumference of the workpiece (eg. When
turning down the outer surface of a cylinder
or the inner wall of a hollow round box). Using
this method, the surface being turned travels
under the edge of the chisel like an endless
belt. The second approach is towards the
diameter of the workpiece (as when turning
the face when faceplate turning, or the side of
a large shoulder when spindle turning) using this method the surface being turned
rotates like a disc under the chisel edge. Some jobs will require both methods being
used. See
Fig. 23
.
Either a cutting or scraping action may be used when the method used is towards the
circumference – the shaving will come off like the peel from a potato.
Only scraping can be used when the method used is towards the diameter. The reason
for this is obvious when you consider that faceplate turning nearly always requires the
removal of wood across the grain. Wood does not peel easily when turning across the
grain and any attempt made to use cutting methods will probably result in damage to
the workpiece and the chisel being thrown by the workpiece.
It therefore follows that a cutting action is used for general spindle turning operations,
while the majority of faceplate turning is carried out by the scraping method. when
both methods are to be used, you will have to judge by the feel of the workpiece when
to stop cutting and start scraping. NEVER try to cut when it becomes difficult to hold
the chisel against the wood grain.
Fig.23.
DIAMETER
APPROACH
CIRCUMFERENCE
APPROACH