Cutting down QCTP tool holders

We've touched on this subject. The BXA QCTP I bought for my Grizzly G0773 lathe / mill combo (12 x 27 swing & c - c) doesn't sit low enough on my cross slide. I couldn't begin to mill the holders as they are too hard. So it was suggested that I mount 1 up in the 4 jaw & starting from the center, cut it to size. OK, got it chucked up. What insert or cutter should I use?

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Depends what you have available. As it will be an intermittent cut I'd consider which of my current tooling has the strongest cutting edge. For me it is a WNMG cutting tool. Maybe also have a look to see if any inserts are available for intermittent cutting as these will have a stronger cutting edge.

That being said most any carbide tooling should work OK. Just take it easy and expect that you may chip a few inserts.
 
We've touched on this subject. The BXA QCTP I bought for my Grizzly G0773 lathe / mill combo (12 x 27 swing & c - c) doesn't sit low enough on my cross slide. I couldn't begin to mill the holders as they are too hard. So it was suggested that I mount 1 up in the 4 jaw & starting from the center, cut it to size. OK, got it chucked up. What insert or cutter should I use?

View attachment 278418

How much over height are you? Aloris and Shars both sell oversize tool holders for BXA. The floor of the Aloris 2S slot is 7/16" and for the Shars 201-XL, its 3/8".
 
That looks spooky, I would think carbide end mill should cut it, better yet surface grinder
 
This is a Shars AXA boring bar holder that I modified. I used an insert boring bar, bur the cut became interrupted as I got into the pinch bolt bosses. Nevertheless, it machined without much effort.
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(from mobile)
 
I hardness tested a Chinese AXA boring bar holder, and it came up as Rc30, not so very difficult to machine, especially with carbide.
 
I am surprised that a part like this could be machined on a lathe but not on a mill. Comments?
Likely, it could be milled just as easy, but for the holder being bored as is shown, it would be faster in the lathe; if the bottom was to be machined as in the original post, if one had an insert end mill or face mill, milling would likely be faster, and its likely to have the bit or insert chipped when passing center if done in the lathe.
 
I am surprised that a part like this could be machined on a lathe but not on a mill. Comments?
I think that it has something to do with the quality of the tool and the rigidity of the setup. Somehow, facing on a medium lathe is more solid than surface milling with a Jet Bridgeport clone. That was what I found at Techshop, when I was a member. I was trying to cut 4140 prehard, and the heavy mill felt like it was about to shake its table off. There was little progress on the slot I was cutting. The lathe tools, while hand sharpened, probably had a superior edge in comparison to the cheap Chinese gold colored public end mills. Since I had to cut a slot, I eventually TIG welded a small vertical geometry fly cutter with a cobalt (hand sharpened) lathe bit in it. It was able to finish the job on the mill where the cheap end mills failed. Even a broken drill bit in a block toolholder is capable of doing some tough cutting in a lathe.
 
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