Thread: Quick test of Cermet CCMT inserts

Originally Posted by andrew_mx83

Anyway, back on topic -have you tried a decent cut yet Ray?

Yes, stalled the motor ( well tripped the current limit on the VFD )

Ray

Originally Posted by RayG

Yes, stalled the motor ( well tripped the current limit on the VFD )

Ray

*Now* you're talking! Time for a bigger motor. If the chips aren't red hot (instantly turning blue) off the tool, and shooting at least 1m away to burn hell out of the operator and anyone nearby - it's time to up the speed & feed.

.... and stop machining in T shirts & joggers, because the chips melt through the uppers and it's hard to get them off fast enough. Guess how I know that.....

PDW

Bit to read about Kyocera cermet inserts here:
Cermets Get Assertive : Modern Machine Shop
Generally though with the 0.4 nose radius of the inserts you have, would make them a good finishing and light cutting insert only.

Originally Posted by Clubman7

Generally though with the 0.4 nose radius of the inserts you have, would make them a good finishing and light cutting insert only.

Ha, where's your sense of adventure...

Ideally I'd prefer it if these would actually give a good finish on light cuts, but so far I don't think they are as good as the CCGT high rake inserts on light cuts.

Ray

Originally Posted by PDW

*Now* you're talking! Time for a bigger motor. If the chips aren't red hot (instantly turning blue) off the tool, and shooting at least 1m away to burn hell out of the operator and anyone nearby - it's time to up the speed & feed.

.... and stop machining in T shirts & joggers, because the chips melt through the uppers and it's hard to get them off fast enough. Guess how I know that.....

PDW

Pretty much what he said....
If you are cutting properly the chips will melt into your skin in a few seconds.
Generally my chips are white right at the cut zone then turn blue after 1mm or so.


WRT stalling the motor, you are on the right track. For heavy cuts i just juggle the feedrate until you can hear the motor load right up. Basically feed it as fast as you can til the motor slows. I have my vfd setup to drop the frequency (speed) when the current limit is reached, rather than shut down so i can keep working and just back off the feed a bit until it recovers.

Keep at it, they take some getting used to but are well worth it once you work them out.

Using the lathe today and remembered this post so thought i'd drag it up for a little more comment. CCMT inserts, 8.5" x 16" lathe, 10mm tooling, cold rolled bar, 5.25mm cut!!! Can't take much bigger a cut with these inserts, the edges are only 6mm. I have loaded the whole edge up before though. These inserts slice through stainless well to, beautiful bright blue ribbons. With CCMT inserts the SCBCR/SCKCR holders come in handy, lets you use all four corners, that's SCBCR in the pic. I took some video for the untrusting, lol. Don't know how to post it though if someone could help?

This is a heavy cut on a tiny 95kg lathe...

20140205_185502.jpg

Originally Posted by slhouetteV8

I took some video for the untrusting, lol. Don't know how to post it though if someone could help?

Upload it to youtube. or vimeo.

Ray

Originally Posted by RayG

Ha, where's your sense of adventure...

Ideally I'd prefer it if these would actually give a good finish on light cuts, but so far I don't think they are as good as the CCGT high rake inserts on light cuts.

Ray

Hi Ray,

What CCGT high rake inserts are you using? I wouldn't mind finding something less expensive than the Kennametal KC5010 grade inserts I'm using. The Cermets have a strong appeal but the eBay offerings I have seen have not been high positive/rake. Flat stuff doesn't work on my bitty lathe.

BT

Originally Posted by Anorak Bob

Hi Ray,

What CCGT high rake inserts are you using? I wouldn't mind finding something less expensive than the Kennametal KC5010 grade inserts I'm using. The Cermets have a strong appeal but the eBay offerings I have seen have not been high positive/rake. Flat stuff doesn't work on my bitty lathe.

BT

Hi BT,

IMG_0671s.JPG

The two on the left are the high rake , the one on the right is cermet.

Josh has been making shafts for the sliding side gate bearings, so I've carefully posed a couple at the top of the picture.. Nice sliding fit on the bearings and hex heads done on the mill with rotary table.

Ray

Originally Posted by RayG

Upload it to youtube. or vimeo.

Ray

Thanks Ray, vimeo, never heard of it. You tube wouldn't work for me. Video uploaded I'll put a link up shortly.

Okay here's the vid. I'm not laying into this cut, only one hand on the lathe the other leaning over it trying to film, with two hands on the wheel i'd push it harder. Still gets a bit of color as the cut heats up. With the compound removed and a solid toolblock bolted to the crosslide i reckon this lathe would take a 6.5 - 7mm cut in carbide.


https://vimeo.com/85914218


Hopefully that worked.


Brett.

Hi Brett,

That video came out well, handled the cut, no drama... Although, I would have expected a bit more colour in the chips...

Ray

Originally Posted by RayG

Hi Brett,

That video came out well, handled the cut, no drama... Although, I would have expected a bit more colour in the chips...

Ray

Yeah i'm not really game enough to hook into it like that, everything's going pretty fast. I wonder how many people have come to grief over you tube, lol.

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



Ray