Looking for references on Boring

How about starting with the chamber of commerce?

Lathe or mill?

Really, either one is simple if you already have a feel for feeds and speeds.

jsw

Well, I can't tell you a lot but if your bar sticks out more than 4L to 1d with steel, you risk chatter.

Carbide takes you farther down the road since it is stiffer. Can't remember the ratio atm.

Wes

-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller

Make sure your cutting tool/insert is aligned on centerline.

Wes

-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller

Make sure the cutting tool has sufficient front clearance so as not to rub on the inside wall.

Set the cutting edge at or slightly above the centre line of the lathe.

If you get serious vibration slow the speed and/or increase the feed/ rev.

Point 1) and 3) also apply when using a boring head in the mill.

Keep the bar extension as short as possible.

Wolfgang

Another good tip. We were trying to run jobs with 1.5d" boring bars when 2" can be marginal using round turrets where the tool holder adds to the overhang. Thankfully we now have more machines that take 2"d side mounted in decent holders and don't have the problem.

Wes

-- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller

The world is ruled by those who could bore straight holes in guns, big and little.

Get a copy of Kibbe:

Does this apply to all boring bars? I found one (carbide insert) with a negative rake. This puzzled me and some research on the net suggested that it should be used below the center. Is this wrong?

I am happy to photograph it an post on flickr if it helps.

When you are turning a outside diameter in the lathe , you want the tool on the centerline of the part or very slightly below centerline. The reason is that if the tool digs in, it is deflected down which moves it away from the cut. If it is above center, when it digs in , it is deflected down and into the cut. Which makes it dig in more.

When boring everything is exactly reversed. The tool should be on centerline or slightly above centerline. If it is below centerline, if it digs in, it will move down and dig in more. I prefer slightly above centerline. Because boring bars are more flexible than tool used for outside turning. So they are very likely to deflect and if above centerline they will not dig in more. That is true whether the rake is positive or negative.

Dan

It's a town (officially a "village" within the city of Damascus) in Oregon, USA. It used to be a lumber and mill town. Now it's a bend in the road, surrounded by bedrooms that feed into Portland and a whole bunch of nice farmland.

It was founded by a very Boring family.

When you are turning a outside diameter in the lathe , you want the tool on the centerline of the part or very slightly below centerline. The reason is that if the tool digs in, it is deflected down which moves it away from the cut. If it is above center, when it digs in , it is deflected down and into the cut. Which makes it dig in more.

When boring everything is exactly reversed. The tool should be on centerline or slightly above centerline. If it is below centerline, if it digs in, it will move down and dig in more. I prefer slightly above centerline. Because boring bars are more flexible than tool used for outside turning. So they are very likely to deflect and if above centerline they will not dig in more. That is true whether the rake is positive or negative.

Dan While that's of some concern, the biggest one is that boring requires considerable relief, especially on small holes, where the radius of the part is quite small. Running below center often yields dragging of the tool on the front relief, which isn't acceptable.

Harold

Were they related to the Boeings, Boers or Bongs?

Strange things happened to names at Ellis Island. Yeager was Jaeger (hunter, gamekeeper), and I think Chrysler was Kreisler. Cronkite was originally Krankheit (sickness).

jsw

At one time the UK commercial phone directory used to say

"Boring: see Civil Engineers"

There are no 'Civil' engineers. ;-)

Thanks for that, Richard. I just ordered one on ebay. (and I'm still drinking seltzer - the 20# CO2 tank is, apparently, bottomless).

Or about 1000 liters of seltzer, whichever comes first.

It's in there as a liquid, lotsa packaging density. I used it all the time for unclogging AC condensate lines and air dusting, and the tank lasted for months.

Which is why it's great for powering "air" operated things in remote places without electric power and you don't want to change gas bottles very often - if the systems are compatible with it.

Now they sell little 2-pound portable bottles with a carrier and all the accessories, and a Transfill adapter to fill it from a 20-pounder.

-->--