Long hot swarf

[redhouseluv]

Today I encountered very long swarf, which was eventually whipping around the work piece and causing all sorts of problems as well as being really dangerous! I had to stop intermittently to untangle it from everything before continuing; some of the ribbons were over a metre long, you can't really see it in the picture of the floor

I was machining mild steel approx 1" diameter at 800rpm on powerfeed with cut of 020". Should increase/decrease speed, decrease depth of cut? I tried applying some cutting oil, that just smoked and made interesting vapour trails!

[derekwarner]

I am sure many have experienced similar swarf, however it may help if you show the cutting tool & the geometry setup  being used at the time

[crueby]

When manually turning the crank, I'll often stop or slow the turns every couple of revs of the handwheel when the curls get too long, that tends to break them. If autofeeding, seems like changing the speed would do the same thing. I've noticed that when taking multiple passes to bring a bar down to desired size, that it will go in and out of the long-curl-generation mode, so I suspect its surface speed related.

[Jasonb]

A faster feed rate should help break it into chips as the thicker swarf is not as flexible.

[john mills]

what is the shape of the tool
have you got a chip braking shape  or a groove or a step  a shaped insert or a ground tool.
A faster feed if you can can help chip braking shape work better.dificult for finishing cuts as you want a finish.
John 

[redhouseluv]

Thanks all

I have attached some photos of the tool in question; I finished off by using a smaller CCMT tool with finer cuts and this gave a better finish and chips rather than long ribbons

[internal_fire]

I have attached some photos of the tool in question

W-style (Trigon) tooling is very strong, but is not the best for fine finishing. The edges tend to be stronger and blunter than those available for C-style and T-style inserts.

Even the sharpest available inserts, often designated by xF or FF in the latter part of the model number, are not as sharp as the "razor-edge" inserts available in the other shapes.

The "chipbreaker", which is common to many W-style inserts, really only works with heavy cuts. For anything less than, say, 0.010" the chipbreaker does nothing except make the curl tighter.

I use W-style inserts quite a bit, but for light cuts or fine finishing it is better to switch to a sharp insert or HSS.

Gene

[Jasonb]

I would not generalise that all W shape inserts are not sharp, You can get them polished and ground for non ferrous and stainless steel that are a lot sharper than the pressed type you look to have there. Though the sharper is less likely you break the chips anyway.

https://www.shop-apt.co.uk/carbide-inserts-for-turning-aluminium-alloys-non-ferrous-metals-plastics/wnmg-060404-alu-ak10-carbide-inserts-for-turning-ground-and-polished-for-aluminium-uni-tip.html

[internal_fire]

I would not generalise that all W shape inserts are not sharp, You can get them polished and ground for non ferrous and stainless steel that are a lot sharper than the pressed type you look to have there.

Interesting. I have looked at all the big guys like Sandvik, Kennametal, Iscar, Kyocera, Mitsubishi, etc., and I did not find anything like those.

Guess I should look elsewhere. 

Gene

[bent]

In the first photo, it looks like the tip of the tool is damaged/broken, may have affected the performance as far as chip breaking.

[Jasonb]

Now I've clicked to the larger size would agree that corner is passed it's sell by date

[redhouseluv]

Okay, thanks - hopefully a quick rotation should solve the issue