Boring first time with the 618 6" lathe

[forwheeler]

I used my lathe for the first time a few days ago. I bored out a cast aluminum pulley and used a boring bar for the first time. I put the small old craftsman bar in the lantern but the tip of the bar was above the centerline of the work. Is there another tool holder I am supposed to use for boring or can I use the same holder and lantern that I will use for turning?

 

[forwheeler]

I can rotate the bar so the cutting edge is pointing down slightly and then it should be at centerline but that doesn't seem right to me.

 

[Tony Wells]

If you rotate the bar, you change the cutting edge angles. If you grind properly, nothing wrong with that. There are Armstrong style bar holders, but with some thinking, and some spacers, you can do it. You won't quite the rigidity, because you can't get as close to the work as with a proper bar holder, but you can get by.

 

[wa5cab]

Technically, a cutting tool can be at any angle to the horizontal so long as it approaches the work at the proper angles to the tangent to the contact point. It's just easiest to set if the proper angles are achieved at the 3:00 or 9:00 points (assuming that the lathe bed is level). If you are going to be doing a lot of boring, Atlas also sold a dedicated boring bar holder that mounts to the compound in place of the lantern holder. Stiffer than the lantern, too. Myself, I use a QCTP with holders that have vertical as well as angular adjustment.

Robert D.

 

[wa5cab]

I agree about the QCTP. I still have the lantern tool post and complete set of tool holders in the fitted steel case. But haven't used any of it since I bought a 100 Series Yuasa set in the Summer of 1981.

Robert D.

 

[forwheeler]

Here are some pictures of the boring bar and holder I am using. I want to make sure this looks right to you guys.

 

[forwheeler]

Yes I see what you mean in the manual. I need to decide whether to buy those parts or go to a different holder. I assume the consensus is a different holder.