External turning with a boring head

[Mr Ron]

With a boring head, one can bore holes of any size. I have seen where one can turn an external diameter using a boring head, but the cutting bits cannot be reversed to cut externally. I would think bits would be available to do external turning, but I can't find anything anywhere. Is there such a thing?

[Richard_W]

Look for a Left had boring bar.

https://www.ebay.com/itm/1-2-Turning-Bo ... XQ-alQ4b2b

https://www.ebay.com/itm/3-4-Boring-Bar ... SwPe1T8q08

[Magicniner]

Use a left hand boring bar or reverse your mill!

[Mr Ron]

I searched through the MSC catalog on line, but did not see any left hand bars. I noticed they were listed as "right hand cut", but could not find any listed as "left hand cut".
Richard_W; Those left hand bars are for the cross hole in the head. I want the left hand bars that operate in the vertical position.

[warmstrong1955]

LH available here, and I have some: http://www.mesatool.com/products/boring-bars/

Good tools. I have many from Mesa.

Bill

[tornitore45]

My boring head has a threaded shank and could not be run in reverse.

I drilled a hole at a convenient angle to intercept the shank thread almost tangentially then tapped the hole, then milled a divot on the shank thread where the set screw would touch. The set screw hold the tread from unscrewing. Now I run the boring head in reverse with the usual RH boring bar. Cheaper than a LH boring bar to be rarely used.

[Richard_W]

Richard_W; Those left hand bars are for the cross hole in the head. I want the left hand bars that operate in the vertical position.

Think about it some more. Some times things are hard to visualize. I have used left hand boring bar on the lathes. Both CNC and manual. They will work just fine for turning an O.D. with a boring head in the vertical position. I have done it. Usually on larger parts on an HBM with a boring head.

You are right that they will work fine out the side hole. I have done that to.

Richard W.

[RMinMN]

My boring head has a threaded shank and could not be run in reverse.

I drilled a hole at a convenient angle to intercept the shank thread almost tangentially then tapped the hole, then milled a divot on the shank thread where the set screw would touch. The set screw hold the tread from unscrewing. Now I run the boring head in reverse with the usual RH boring bar. Cheaper than a LH boring bar to be rarely used.

A bit of lockite on the threads will solve the problem of not being able to run in reverse. Heating the head can destroy the bond so you can later unscrew it if necessary.

[Mr Ron]

LH available here, and I have some: http://www.mesatool.com/products/boring-bars/

Good tools. I have many from Mesa.

Bill

The shortest one is 3" long; too long to be used vertically; that was designed for use in the horizontal cross hole. My mill doesn't reverse and the head is screwed onto the shank.

[Mr Ron]

I could turn the diameter on the lathe, but sometimes you may have a setup on the mill which may require a diameter feature to be incorporated. It is more precise to do all machining operations with one setup. It's like having a 4 axis machining center.

[warmstrong1955]

Is 3" too long due to the size of your mill? I have RH bars from 3" to 8", which I have used vertically, for ID's of course.
If you are turning the OD, the machine will need to be turning forward if you use a LH bar.

Bill

[ChipMaker4130]

A bit of lockite on the threads will solve the problem of not being able to run in reverse. Heating the head can destroy the bond so you can later unscrew it if necessary.

Careful, here. After thorough cleaning, using 'red' loctite and allowing full cure, the shank on my boring head came loose running in reverse on what amounted to an interrupted cut while taking off the high spots on the part. It worked fine after it was all round though.