Why is the slot on the body of a fly-cutter offset from
Is it so that the cutting edge itself is brought onto
the line of a diameter?
On the Chronos fly cutter that I have, the cutting bit
is about 6" long and 1/4" square.
How much should protrude at the sharp end? It seems to
me that if there was more than, say, 1", that there would
be destructive forces tending to bend or to shatter the cutting
When using fly cutters and planing bits in hand shapers,
surely as the cut proceeds, the cutting bit will wear and
that therefore you will not end up with a uniformly flat
And one further question....
What shape do I grind the cutting end to be?
Does it have to be somehow the shapes that are advised
for lathe tools, i.e. a knife, and a different shaped knife for
brass and for steel?
I usually make a small radius, as seen from the side of the
flycutter. This radius would be the cutting edge as it faces the work.
I just leave the "top" (as if it were a lathe
tool) flat. So, you can take the tool blank and just round off
one corner, and put a little back relief on it. I use some
old cobalt HSS cutters, and they do amazingly well on aluminum