Right/Left boring bars - newbie help needed!

Thanks Billy. I found it at my local flea market for fifty bucks a few years ago. Since then I've spent thousands for a complete collet set and tons of other accessories, all by the original maker...Rivett.
 
I agree - that is a beautiful lathe! Craftsmanship like that will never come out of China.

Your tool holder will work fine for the carbide bar I cited. Yes, Kennametal owns Circle Machine now but CM products are still produced. I would not recommend buying this bar retail; too expensive. Wait for it to come up on ebay and buy the bar and inserts there if you are interested. If I could only have one bar I would buy this one for the scale of work your lathe can handle. Used correctly, it is extremely accurate and will serve you well.

Nose radius on inserted tip boring bars are extremely important, especially on smaller lathes. Yes, it is the radius on the cutting tip of the insert and the size of that radius will help guide your depth of cut, feeds and speeds for both roughing and finishing passes. The geometry of the bar, the insert, and the nose radius has to do with minimizing or accommodating the cutting forces inherent in the boring process.

I'll contact you by PM later to clarify this a bit more.
 
I'm even more of a newbie than the newbie. In the 3 photos of the boring bar, is that right or left handed? I need to make some for my lathe SB9A, the chuck of which is screw on, so I want to have my chuck running counterclockwise, which is forward direction

oh, one more thing. If the boring bar is left handed, is the cutting part right or left handed. And do all left handed boring bars have right handed tips or how does that work?

Dave
 
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mikey said:
I agree - that is a beautiful lathe! Craftsmanship like that will never come out of China.

Your tool holder will work fine for the carbide bar I cited. Yes, Kennametal owns Circle Machine now but CM products are still produced. I would not recommend buying this bar retail; too expensive. Wait for it to come up on ebay and buy the bar and inserts there if you are interested. If I could only have one bar I would buy this one for the scale of work your lathe can handle. Used correctly, it is extremely accurate and will serve you well.

Nose radius on inserted tip boring bars are extremely important, especially on smaller lathes. Yes, it is the radius on the cutting tip of the insert and the size of that radius will help guide your depth of cut, feeds and speeds for both roughing and finishing passes. The geometry of the bar, the insert, and the nose radius has to do with minimizing or accommodating the cutting forces inherent in the boring process.

I'll contact you by PM later to clarify this a bit more.
Click to expand...

Mike, thanks VERY much for your learned perspective - that's why I come here! PM received and responded to.
 
Doug, that is a sweet piece of machinery! What a beauty! I'd love to have that just to ogle it every day. :p
 
One more question for Doug. The 3 pictures of the boring bar you made. Looking at it, it seems that the cutting part of the bit is right-handed. I just went online to look up boring bar bits and it said they should be left-handed when using the lathe in a normal CCW rotation.
 
The bar he is holding would be a left hand bar chuck spinning CCW. Although you could turn it around and cut on the right hand side the chuck would still need to turn CCW. the cutting edge would be on the bottom in that case. Now this is looking at the lathe from the tail stock end.
 
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