Reverse Boring Bar?

yukon_rose

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I have a nice collection of boring bars. But without exception they all point left. That is, if you hold a bar vertically with the cutting edge visible at the top, the cutting edge is on the left.

That's all well and good but frequently I want to cut something where having the cutting edge on the right would be ideal. The situation typically occurs when I'm cutting a slot on the lathe. And it ALWAYS occurs when I use a boring head in a mill.

Do "Right Handed" boring bars exist?

Gary
 
Any in HSS?
Not that I've found, how about HSS inserts?
For future reference, the type you have are right hand.
 
As MrWhoopee stated, what you are looking for is a LH boring bar (pointing to the right held in the orientation as you described).

Using a RH boring bar upside down to cut on the far side of the bore (away from you), you would still run the spindle in forward though (counterclockwise). If you use a LH boring bar like you want, then you would run the spindle in reverse (for an inside bore).

I'm curious why you want to use a LH boring bar, I've never ran in a case where I wanted one. I know you stated to cut a slot on the lathe but that sounds like a broaching type operation using the carriage & a boring bar doesn't seem to be ideal for that?

Something to consider IF you have a threaded spindle. If running a LH boring bar & running the spindle in reverse, there's a risk that your chuck can unthread.

Same if you run a LH boring bar in a boring head in the mill, need to run the spindle in reverse. Boring heads usually use threaded arbors so there's also risk of the boring head unthreading running in reverse.
 
I recently had a need for one of these. I needed to put a 7" radius on some aluminum flat bar in the mill. My boring head was only designed for 2", So why not put a boring bar in the horizontal slot in the boring head. Well with a standard boring bar I'd have to run the mill in reverse, this ended up unscrewing the boring head from the arbor, so I made a bar to fit the boring head horizontal slot, welded a piece of HSS parting blade to the bar. It was crude but worked. Now the radius that be can cut is almost limitless.
 
Do "Right Handed" boring bars exist?

Gary

Gary:

You can always make one to suit your needs.

I needed to cut to cut the outside profile of an IC model engine cam. I simply made a LH boring bar from CRS and a chunk of carbide insert then ran the mill in reverse.
Bill

LH Boring Bar - 2.jpg
 
Another time when a LH boring bar would be needed: milling a boss.
As mentioned above, the boring head will unscrew from the arbor (if I could run my Mini-mill in reverse.)
I don't recall the project, but this situation did occur to me a few years ago. The design had called for a round boss around a hole. Somehow I avoided the issue, perhaps by just milling face, approximating a circle by eye and hand. Or maybe I redesigned the project to obviate the need.
I did search for LH boring bars compatible with my boring head and don't recall finding any. Next time, I'll check Shars.com.
 
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