"Bill Schwab" wrote in message
ink.net...
Harold,

I've always preferred fly cutters with 3/4" shanks. It makes it much
easier
to go from an the cutter to a drill chuck or other device.

In my case (ER 32), any round vs. R8 shank will make life easier. Is
there something specific to your setup that is specific to 3/4"?

Yes. All of my drill chucks aside from one Albrecht, 1/8" capacity, have
3/4" straight shanks. That's be design, so it's fast and easy to go from a
fly cutter, end mill, or drill chuck without having to change the collet.
It's a very good system when you're involved in low level production (read
that non-CNC), which I was. If you are doing one off, it's not all that
big of a deal.


If the shanks
are less than 3/4", I'd likely feel differently. I couldn't get
interested in a 1/2" shank, for example. With the smaller shanks,
you're
asking for chatter.

3/4 it is. I have an ER collet in that size, and the Enco set with that
shank size has 1.5, 2, and 2.5 inch diameter cutters, which is a nice
range for most of what I do.

That choice leads to 5/16 inch tool bits. Would HSS square bits be a
good place to start?

Depends on the work at hand. There are times when brazed carbide are the
answer, but in general, you'll be well served by HSS. It won't matter much
when machining aluminum or most of the copper alloys, but when it comes to
machining steel, you'll often be better served by running carbide and
kicking up the speed somewhat. Once you start using a fly cutter, you'll
quickly discover what works best for you in your particular circumstances.
Don't close the door on any of the options where toolbits are concerned.
They all have a place.



Unless you're machining steel, taking heavy cuts, rigidity isn't much of
an
issue. I'd suggest you permit your work to make the decision. If you
expect you'll be doing lots of big stuff with deep cuts and large
diameter
circles, the R8 would be a better choice.

I am unlikely to need to take deep cuts. With the exception of my
bandsaw helping me to improve my rough cuts, I try to avoid being in a
hurry.

Thanks!

Bill

Welcome.

Fly cutters work very best for light cuts, so you're on the right track. I
generally use a 3/4" end mill if I'm moving much steel, then go to the fly
cutter for finish. Once again, a good reason to have a collet size
instead of an R8.

Harold