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Insert seat damage when turning copper

Is that the seat screw it came with, images I have looked up none look like that, most have a lot more surface area on the top and smaller center hole, just wondering.
SCLCR163
Kennametal catalog mentions CC...3252 gage insert, what ever that means but in reference to the inserts its applies to the 1/32 corner rad, dont why that would have anything to do with the tea in china.

I would say roll with a different type holder, something with dual support.

If I had to guess, looks like the wrong shim screw(hole too big), but anyway, I would say your getting insert screw flex, forward, and that then is allowing the insert once pulled away from its wall seats to wobble back and forth, there by widening the seats over time.
So like I said something with a larger better support, not just a little set screw in the middle.
 
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Is that the seat screw it came with, images I have looked up none look like that, most have a lot more surface area on the top and smaller center hole, just wondering.
SCLCR163
Kennametal catalog mentions CC...3252 gage insert, what ever that means but in reference to the inserts its applies to the 1/32 corner rad, dont why that would have anything to do with the tea in china.


Means it'll fit a CCXX 32.52 gage insert.

Example: 1716498464646.png
 
This a picture of the actual insert and holder in use?
If so .. many things wrong.
No, this is a picture of a 3/4 shank tool that holds the same insert. There's also no screw or insert in the holder, it's empty.
This tool was damaged in the pocket like I initially described. I only kept it because I figured i'd cut it into pieces and use it for something at some point.
It's hard to see because the picture is grainy and it's just a few thousandths of damage to the pocket. Part of the problem is that this issue isn't apparent by looking at the tool, only when you go to seat an insert and see it shift as you tighten it down.

The mclnr is the holder. You'll probsbly want cngp inserts. Call tech support!

Yeah I'm typing quickly and not paying close enough attention to my words.. I know it's the holder and not the insert, but thanks

Also to note: I'm not sure if the seat is being damaged by one event where the chips get smashed up against a wall, or if over time the pecking cycles (think 10" diameter copper by 10" long slug...) are just repeatedly pounding the insert into the steel shank until it has a slight impact , like just a few thousandths?
Hard to know... but I think the neutral insert idea is good, for obvious reasons, however I'm not excited about revisiting a chip issue in copper by changing tools. But it is what it is so might just do that
 
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Not sure if you can really see the "damage" to the back of the insert seat, but it's there. The insert can move back and forth even when tightened down.

Are you sure it's the walls of the pocket that are getting worn rather than the screw and female threads that accept the screw? In other words, have you tried replacing the seat-retaining hollow screw and the insert screw to see if that eliminates the slack?

Have you tried an SCLCR without carbide seat where the screw goes straight into the floor of the pocket? I'm thinking that since you're pecking maybe the problem is that the insert is getting pulled out of the pocket a little on every retract and then pushed back in on every plunge and that it's able to do that because the insert screw is longer and more flexible than if the seat weren't there.

The cam pin on an MCLNR might resist the pulling, or it might just work loose. I don't know.

I'd be be tempted to try something like Sandvik iLock where there are tapered keys that prevent the insert from shifting:
iLock.png
 
Those Sandvik ilocks are good at preventing insert movement. I had VNMGs moving and changing part size on me, but the Sanvik TR-VB inserts solved that problem.
 
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Are you sure it's the walls of the pocket that are getting worn rather than the screw and female threads that accept the screw? In other words, have you tried replacing the seat-retaining hollow screw and the insert screw to see if that eliminates the slack?

Have you tried an SCLCR without carbide seat where the screw goes straight into the floor of the pocket? I'm thinking that since you're pecking maybe the problem is that the insert is getting pulled out of the pocket a little on every retract and then pushed back in on every plunge and that it's able to do that because the insert screw is longer and more flexible than if the seat weren't there.

The cam pin on an MCLNR might resist the pulling, or it might just work loose. I don't know.

I'd be be tempted to try something like Sandvik iLock where there are tapered keys that prevent the insert from shifting:
View attachment 440886

Great point on the screw/threads. I haven't tried swapping the seat/female thread insert but I will definitely do that next time and see if that may be the issue.
Yes, the SCLCR without the carbide seat does the same thing.

The MCLNR is interesting and I'm definitely looking into it.
That Sandvik looks very interesting too... these are great suggestions thank you.

Those Sandvik ilocks are good at preventing insert movement. I had VNMGs moving and changing part size on me, but the Sanvik TR-VB inserts solved that problem.

Awesome. Looking into this now. What you're describing with repeatability is very enticing. The cost of copper is incredible
 
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Those Sandvik ilocks are good at preventing insert movement. I had VNMGs moving and changing part size on me, but the Sanvik TR-VB inserts solved that problem.
iLock holders are great for insert repeatability, but they are not immune to wear and are quite easily damaged if you break an insert. The increased cost of them needs to weighed against the potential process benefits...

I use them a lot on deep bores with silent bars, but I'm not sure I'd bother with them for something like this.

Are you sure it's the walls of the pocket that are getting worn rather than the screw and female threads that accept the screw? In other words, have you tried replacing the seat-retaining hollow screw and the insert screw to see if that eliminates the slack?

Have you tried an SCLCR without carbide seat where the screw goes straight into the floor of the pocket? I'm thinking that since you're pecking maybe the problem is that the insert is getting pulled out of the pocket a little on every retract and then pushed back in on every plunge and that it's able to do that because the insert screw is longer and more flexible than if the seat weren't there.

The cam pin on an MCLNR might resist the pulling, or it might just work loose. I don't know.

I'd be be tempted to try something like Sandvik iLock where there are tapered keys that prevent the insert from shifting:
View attachment 440886

You can see the pocket wall wear in the picture he posted. It's kind of difficult to see with the red dye, but it's there if you look closely.

I think the suggestion of single sided high positive CNxx inserts is the best one so far...
 
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I use them a lot on deep bores with silent bars, but I'm not sure I'd bother with them for something like this.

Is that because Sandvik is strong-arming you into using iLock inserts on their toolholders, or have you found that there's a particular benefit on damped boring bars but not on other tools?
 
Is that because Sandvik is strong-arming you into using iLock inserts on their toolholders, or have you found that there's a particular benefit on damped boring bars but not on other tools?

Not specifically for damped bars, but SL modular bars generally.

The ilock tools have much better clearances around the cutting edges and better tool geometry/reach options for contouring and backboring etc inside bores. All a result of requiring much less pocket around the insert compared to conventional inserts.
 
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