Thread: Quick test of Cermet CCMT inserts

Originally Posted by andrew_mx83

That's more like it fellas!

you were in short sleeves and there was no screams of pain from hot chips, so crank it up another notch

sadist .....

Originally Posted by RayG

Another Cermet CCMT video... noisy bugger...

Ray

Looks good Ray. What look even better are the short chips. The high positive inserts I use produce continuous strands of swarf which, when turning 4140, are particularly nasty. What is the horsepower of your lathe's motor? Mine's 1.

Oh, and have you tried the cermets on 4140?

Bob.

Hi BT,

I think from memory it's 1.5Kw 2hp, but now I need to go and double check...

Same problems with chip breaker and not enough DOC on 4140, but I feel a bit of playing around might come up with a combination that works for 4140.

I still like the high rake for sneaking up on size.. Josh prefers the HSS shearing tool.

Ray

Hi Ray,
Is your lathe really that loud at high speeds, or is it just the video?

Do you have a DRO? I'd be interested to see if you can reliably take a 1mm DOC to size with it. take a clean up cut on a bar, then take another 1mm DOC. Measure, set DRO to this size.
You need to machine to 30.00mm. Cut to 32.00mm on the dro and then take the last cut to 30.00mm. You have taken the same size cut as when you set the dro so it should be accurate.....

I use a normal HSS tool for creeping up on a size, i find the Shear tool is too slow as it doesn't like a high feed rate.

As far as chip breaking goes i have 2 words....negative rake! My WNMG's have no problems breaking the chips on 4140.

Ew

Originally Posted by Ueee

Hi Ray,
Is your lathe really that loud at high speeds, or is it just the video?

Not that loud at all, it's quite a bit louder..

Taking a deepish cut to hit final size, hasn't worked on this machine. A more rigid cnc machine, yes of course.

I'll try negative rake on the next 4140 job. Those long razor sharp ribbons are deadly.

Ray

Originally Posted by RayG

Another Cermet CCMT video... noisy bugger...

Ray

Looks good to me Ray, finish looks okay to for MS. I wouldn't have thought 1.5kw would be that easy to stall. I'll put up a vid on some harder stuff latter if I get some time.

Ueee, hand fed cut, one pass 41XX, quick and rough setup...

Diameter = 9.31mm

D.O.C = 1.15mm

Target Diameter = 7.01mm

Actual Diameter = 7.025mm

Mic1.jpg

For some reason I can only upload one pic per post?? Anyway, setup for the cut...

Setup.jpg

Finished cut...

mic2.jpg

Thanks. I'm still tossing up whether I should get a dro for the lathe at the same time as the mill or just live without one. I've done ok so far.....

Ew

No worries. Yeah nice to have one but not a necessity, a couple of cheap vernier scales would be good enough for a lathe if you were that wayinclined... The mill on the other hand, now that's a different story

Originally Posted by slhouetteV8

For some reason I can only upload one pic per post?? Anyway, setup for the cut...

Setup.jpg

Hi Silhouette,
there is a plus sign so you can upload more than one.

Phil
screen grab 1.jpg

Originally Posted by Steamwhisperer

Hi Silhouette,
there is a plus sign so you can upload more than one.

Phil
screen grab 1.jpg

It wasn't just Silhouette requiring that tip Phil.

I thought it was a new forum ploy to discourage multiple images accompanying a post. It was working.

Bob.

Originally Posted by Steamwhisperer

Hi Silhouette,
there is a plus sign so you can upload more than one.

Phil
screen grab 1.jpg

https://www.woodworkforums.com/f36/manage-attachments-180993

I thought it was just me to start with....

Ew