I need some recommendations on CCMT inserts

[G-ManBart]

I worry about alignment for parting and threading. Pretty much anything else, I'm just "ballpark". I've done it every which way and there really isn't a discernible difference when using carbide (because it will have the same edge and clearance all around) while conventional HSS cutters can be more picky because they are not usually symmetric. Nothing wrong with setting everything square, it's just not a requirement, nor would I expect one to see any improvement from it.

GsT

There would be an improvement if the tool was set at an angle that allowed too much of the insert to come in contact with the shoulder, causing the chatter he's experiencing. The same could be true if too much of the insert is touching the work when facing causing the chatter he describes.

Someone with your experience won't usually make those mistakes, but someone just learning might easily run into that problem and not know any better. That's why I described what I did...eliminate the mistake variable and put that particular tool parallel to the chuck. That way we know the geometry is at least ballpark close enough and if he's still having a problem, it's time to look at other factors. It also lets him do the two operations he's talking about without making any changes....win-win. If it doesn't help it's still not going to hurt, which is important when trying to fix a problem.

 

[D.sebens]

After some clear head thinking I know why I had the issue with the shoulder. I was rough turning and was stopping near the shoulder but not turning all the way to the stop. So I ended up with the shoulder moving out incrementally. Then I would try to turn in and that’s when the chatter was an issue.

 

[mmcmdl]

After some clear head thinking I know why I had the issue with the shoulder. I was rough turning and was stopping near the shoulder but not turning all the way to the stop. So I ended up with the shoulder moving out incrementally. Then I would try to turn in and that’s when the chatter was an issue.

Those inserts are made to face and turn as you know . Turn to the stop and feed out to face . It will cut .005 on a face while feeding out FWIW . Most CNC lathes use these inserts although a larger size . As to squaring these up true , they should be leaving correct angle clearance . I cant see this making a difference on a manual as your not following a generated path .

 

[D.sebens]

Well I had a chance to try the recommended inserts. I have to say my no name ones must be ground or something. They break easy but the give an amazing finish at .060” doc at 768rpm starting with 1” stock. I was unimpressed with the new ones at first. I decided to try a bunch of different settings. These like my 1300 rpm top speed, .050” doc and .005-.008 in/rev(I was able to do .010” but it was a toss up on if it would chatter).

These inserts really do not like light cuts or slow speed. The light cuts tend to chatter occasionally (light as in .020”. .005” doc seems fine). Slow speed is incredible tearing.

I think the 04 nose radius is great. I struggle to find a setting that works with my lathe for the 08 noise radius inserts. I get a better surface finish slowing down the 04 inserts than I can with the 08 inserts at any speed.

As the stock decreased I would occasionally have a hard time breaking the chip before it was about 3ft long. This is when the stock was about 5/8”. Speeding the feed helped some (I was maxed out on speed with the lathe motor).

I think I need to 3d print all my end gears as the cast iron gears are quite loud at that speed.

I learned some valuable info today. It’s amazing how much material I am able to remove at the higher speeds. I will use that info to find the best spot when I use it for actual use.

 

[Jimsehr]

I have CCMT09T30 inserts on my 11” lathe. My lathe would probably be better suited for hss but I like the finish I get with carbide when it all works. My problem is that the inserts I have chip really easily. They usually chip if I am hand facing or turning to a shoulder and getting chatter from touching the shoulder.

Is this nature of these inserts or is there any recommendations for inserts that can take abuse?

Oh it’s for steel. I have CCGX’s for aluminum.

I am so old I remember the crap tools from when I started in 1953. And I was doing production work on mostly stainless material.
Then we used mostly brazed carbide tools that we hand ground
That was years before carbide inserts were common.
The worst inserts today are much better than what we had.
Most carbides inserts were expensive like 12 bucks each.
Shop rates were $3 bucks an hour.
We did not have all the options in inserts like today.
Most home shops never run 1000 parts at a time.
I laugh at people running 3 pieces and complain about tools not lasting.
I learned to sharpen dull inserts over and over.

 

[Batmanacw]

I have CCMT09T30 inserts on my 11” lathe. My lathe would probably be better suited for hss but I like the finish I get with carbide when it all works. My problem is that the inserts I have chip really easily. They usually chip if I am hand facing or turning to a shoulder and getting chatter from touching the shoulder.

Is this nature of these inserts or is there any recommendations for inserts that can take abuse?

Oh it’s for steel. I have CCGX’s for aluminum.

Is your part slipping?

I used cheap Chinese ccmt inserts for interrupted cuts often. I used a Chinese ccmt insert to bore the jaws on my really bad 12" 3 jaw chuck. Talk about tough conditions. Lol!

Something is going wrong. Maybe your toolpost is moving or your part is slipping?

I get better finishes with the smaller radius and 0.005" per rev feed.

 

[SouthernChap]

Well I had a chance to try the recommended inserts. I have to say my no name ones must be ground or something. They break easy but the give an amazing finish at .060” doc at 768rpm starting with 1” stock. I was unimpressed with the new ones at first. I decided to try a bunch of different settings. These like my 1300 rpm top speed, .050” doc and .005-.008 in/rev(I was able to do .010” but it was a toss up on if it would chatter).

These inserts really do not like light cuts or slow speed. The light cuts tend to chatter occasionally (light as in .020”. .005” doc seems fine). Slow speed is incredible tearing.

I think the 04 nose radius is great. I struggle to find a setting that works with my lathe for the 08 noise radius inserts. I get a better surface finish slowing down the 04 inserts than I can with the 08 inserts at any speed.

As the stock decreased I would occasionally have a hard time breaking the chip before it was about 3ft long. This is when the stock was about 5/8”. Speeding the feed helped some (I was maxed out on speed with the lathe motor).

I think I need to 3d print all my end gears as the cast iron gears are quite loud at that speed.

I learned some valuable info today. It’s amazing how much material I am able to remove at the higher speeds. I will use that info to find the best spot when I use it for actual use.

If you have a way of making gears and fancy the challenge, see if you can source some Tufnol or equivalent. That should give you a quiet set of gears.

 

[Huub Buis]

I also had a lot of noise after replacing the original POM gears for aluminum versions so I switched back to the POM gears. If you put a non metal gear between two metal gears, the noise reduces.
In my bigger lathe I have 3D printed (PLA) gears for some years now. If they break, to reduce damage, I will replace them again by 3D printed gears even I have made new gears out of POM.