Hello all,

The added strength, no worries about slipping, and some extra work for
tool changes that go with R8 are obvious. $28+/- will get me either
three round shaft cutters or one R8.

Since I envision using a flycutter mostly for squaring raw stock, I'm
leaning toward R8, but would be easily persuaded the other direction.
Any preferences?

Bill

"Bill Schwab" wrote in message
link.net...
Hello all,

The added strength, no worries about slipping, and some extra work for
tool changes that go with R8 are obvious. $28+/- will get me either
three round shaft cutters or one R8.

Since I envision using a flycutter mostly for squaring raw stock, I'm
leaning toward R8, but would be easily persuaded the other direction.
Any preferences?

Bill

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. 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.

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. Otherwise, I think you'd be
served quite well with the straight shanks. Think about what I said about
shank size when you make your decision.

If you have a lathe, making your own fly cutter is a great project. That
way you can tailor the slot and holding screws to your liking. Make sure
you keep the cutting edge on center. Fly cutters are also handed, if you
think about it. They should run clockwise, so those without the ability to
reverse their spindle can still use them.

Harold

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"?


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?


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

Bill Schwab wrote in message
link.net...
Hello all,

The added strength, no worries about slipping, and some extra work for
tool changes that go with R8 are obvious. $28+/- will get me either
three round shaft cutters or one R8.

Since I envision using a flycutter mostly for squaring raw stock, I'm
leaning toward R8, but would be easily persuaded the other direction.
Any preferences?

Bill

If you only want to do Mickey Mouse flycutting (3" to 4" diameter) then
something that mounts into an R8 or other mill tool holder will just about
suffice. For serious flycutting (8" to 12" diameter) you want something very
sturdy that clamps round the protruding nose of the quill and becomes an
integral part of it. A picture would be worth a thousand words but I'll try
and describe the one I made for my Bridgeport.

Part 1 is the clamp ring. Some mild steel scrap bar about 2" larger in
diameter than the quill nose and 1" tall. Bore through to the quill
diameter, machine or just hacksaw a slot through the side of the resulting
tube and drill and tap for a 3/8" UNC cap head screw to close the slot up.

Part 2 is the flycutter bar. Mine is 2" wide x 1" deep x 10" long. With
hindsight something even more rigid wouldn't hurt for roughing out. This
attaches to the underside of the clamp ring with two more 3/8" UNC cap head
screws. I slotted my bar so I can alter the cutting diameter. I also
countersunk the slot so the screw heads sit under the surface. This lets me
gets the tallest possible work piece on the mill table.

The cutting tool can be either a brazed tip carbide tool held in the
flycutting bar with a grubscrew or like me you can make a holder for a
carbide turning insert. Mine is a DNMG insert held in place with a 4mm screw
through the centre hole. You want a very sharp edged insert to get a clean
cut so uncoated non ferrous types for aluminium or cast iron are best even
if you're flycutting steel.

With a setup this rigid you can flycut engine blocks and cylinder heads and
put a mirror finish on aluminium with a slow feed and high speed. I can just
about take a 1mm deep cut on cast iron when I'm roughing out but the machine
and everything near it shakes and the noise is fairly intimidating. The
final 2 or 3 thou finish cut on a slow feed puts a finish on cast iron that
almost looks surface ground though.

The only thing I might do in the future is go to a PCD (polycrystalline
diamond) tool which lets you cut very hard materials as cleanly as a carbide
tool cuts aluminium.
--
Dave Baker

On Sat, 21 Jan 2006 22:06:52 -0000, "Dave Baker" Dave
wrote:


Bill Schwab wrote in message
hlink.net...
Hello all,

The added strength, no worries about slipping, and some extra work for
tool changes that go with R8 are obvious. $28+/- will get me either
three round shaft cutters or one R8.

Since I envision using a flycutter mostly for squaring raw stock, I'm
leaning toward R8, but would be easily persuaded the other direction.
Any preferences?

Bill

If you only want to do Mickey Mouse flycutting (3" to 4" diameter) then
something that mounts into an R8 or other mill tool holder will just about
suffice. For serious flycutting (8" to 12" diameter) you want something very
sturdy that clamps round the protruding nose of the quill and becomes an
integral part of it. A picture would be worth a thousand words but I'll try
and describe the one I made for my Bridgeport.

Part 1 is the clamp ring. Some mild steel scrap bar about 2" larger in
diameter than the quill nose and 1" tall. Bore through to the quill
diameter, machine or just hacksaw a slot through the side of the resulting
tube and drill and tap for a 3/8" UNC cap head screw to close the slot up.

Part 2 is the flycutter bar. Mine is 2" wide x 1" deep x 10" long. With
hindsight something even more rigid wouldn't hurt for roughing out. This
attaches to the underside of the clamp ring with two more 3/8" UNC cap head
screws. I slotted my bar so I can alter the cutting diameter. I also
countersunk the slot so the screw heads sit under the surface. This lets me
gets the tallest possible work piece on the mill table.

The cutting tool can be either a brazed tip carbide tool held in the
flycutting bar with a grubscrew or like me you can make a holder for a
carbide turning insert. Mine is a DNMG insert held in place with a 4mm screw
through the centre hole. You want a very sharp edged insert to get a clean
cut so uncoated non ferrous types for aluminium or cast iron are best even
if you're flycutting steel.

Interesting setup. For a look at my flycutter (that I made for
surfacing heads) the first pic on this page shows it in action.

http://members.dslextreme.com/users/.../tailstock.htm

Since my mill has a #40 taper it was easier to make do to the fact
that the there's 4 bolt holes drilled and tapped on the face of the
spindle. Thus I just had to bore a recess that fit the spindle and
then drill 4 holes for the 1/2" bolts to hold it in place on the mill.
I also milled slots for the two keys on the face of the spindle but I
could of gotten by without them (by removing the keys from the
spindle). The size was determined by the stock I had on hand at the
time and was big enough for me to surface a Pontiac 350 head (which
was what I built it for).
Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook/index.htm

"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

In article , Harold and Susan Vordos says...

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.

I love the finish but I always have trouble 'recalibrating' the
spindle speed to keep the sfpm under control. My first attempt
at flycutting invariably winds up with the part getting larger
from one side to the other, and the toolbit gets shorter!

Only then do I wind the speed down after re-sharpening.

I think this is another reason that fly cutters tend to sport
carbide toolbits.

Jim


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