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I was looking at annular cutters. I know you can use them on a drill press or milling machine (I think they are typically used on magnetic drills), but you need to run slow speeds for large cutters.
is it possible to use these on a lathe?
I was just thinking that if I have to drill out a 2" hole, it would be faster to use maybe a 1-7/8" annular cutter and bore out the last 1/8" rather than step drilling in so many steps that you could call it a 12-step program.
You would have to make a holder, as these don't chuck into a drill chuck.
Would this be viable, or would the rotational force be too much, particularly with a Morse taper 2 tailstock?
You are right they need a holder, but the shank is 3/4" dia. I used a Morse endmill holder for a 3/4" end mill to run mine. Just finished 30+ 1 7/8" holes, the size I needed, in 1" steel, using a drill press. Worked like a charm, most of the time. Several of the cutters were probably name brand knockoffs , got a few holes, then they literally exploded, no indication of overload or overheating. With a real name brand cutter, ran the rest of the holes. I also made an adapter to run these in another tool holder.
John Saunders did a tour of a shop where they had trepanning tools for large holes. These were way bigger than your example, but all of these tools (trepanning tools, hole saws, annular cutters) accomplish the same thing. Don't see why it wouldn't work as long as you can make sure it's centered up.
Russ Hanscom wrote: ↑Tue May 19, 2020 11:20 am
You are right they need a holder, but the shank is 3/4" dia. I used a Morse endmill holder for a 3/4" end mill to run mine. Just finished 30+ 1 7/8" holes, the size I needed, in 1" steel, using a drill press.
That would actually give me a double-duty tool as my tailstock and my drill press are both MT2.
You can absolutely run them with your lathe. I try to keep the surface footage around 100sfm and use plenty of lubricant. I like to flood mine, when using them on the lathe. I use an mt4 shank that is modified to hold annular cutters. You could also probably use any collet system that will accommodate 3/4" and hold tightly.
I've used them on my lathe to do exactly what you're intending to do, I used the annular cutter
to cut holes in cast iron lathe chuck back plates, I needed to finish bore a register in them to a certain size.
I bought a MT2 annular cutter holder from Mcmaster, which fits my drill press and lathe tail stock.
Lately I've been using annular cutters on my mill with a dedicated annular cutter holder.
They work quite nicely in a 3/4 collet. There are straight shank and MT shanks available. I have an MT3 shank. I don't know if MT2 is available. I have a 5/8" straight shank holder I don't use but is missing the spring and pilot.
Bill Shields wrote: ↑Tue May 19, 2020 6:24 pm
Are you drilling a blind hole into thick material?
I was looking at thru holes.
Can't envision a use of using one for a blind hole, but I'm sure there's something.
Steve
Interesting thought on using them for a blind hole, I'd guess if you had annular cutters
that would overlap enough, it would be possible.
That would probably not be much different than step drilling.
If you actually needed a ring shape milled into something, like if a tube needs to go inside something and have the material both inside and outside the tube, an annular cutter would work.
