A flycutter, if holding a HSS bit, can't run nearly as fast as the carbide mill.
Also, a carbide endmill with N inserts can be fed N times as fast as a single
point tool like a flycutter. Most people use them like flycutters, only they go
a whole lot faster. Flycutting is good for the soul, but when you want to get
done, use a multitooth cutter.

GWE

Rex B wrote:


I bought a small one in the process of acquiring standard tooling for a
new minimill, but am a bit vague about the correct use of it.
Conventional fluted mill seem to fit most of what I'd be doing, and
flycutter is for finishing a surface. So what is the indexible
carbide cutter best used for ?



You really need a powrful rigid machine to successfully use carbide
insert tooling. Me thinks your machine can't use it to advantage. For
insert tooling, you just replace an insert when dull and you're back
to a brand new cutter with the exact same dimensions. No regrinding or
changing to a new cutter and having to re-establish all your offsets.
Big time saver.

For small one of jobs like most hobbist have, regular endmills end up
cheaper. You almost cry when you schmuck a $150 holder with $40 worth
of inserts into your brand new vice and almost finished part. If you
haven't schmucked an endmill yet, you're not a machinist.

Karl


Let me rephrase the question then.

The insert holder I got was a 1.25" diameter R8 unit with 2 triangular
inserts. I understand from the minimill old-timers that this is the
appropriate size and the machine has sufficient power to drive it.
What I don't understand is, for what operations or projects is this
the most appropriate tool, as opposed to a 4- or 2-flute endmill, or a
flycutter? Is it the thing to use when you want to cut a finish
surface on a 4" square block? Or is it better suited to bulk metal
removal, such as to make that block 1/4" thinner?