World Record chip length? I may have a winner

M

MontanaLon

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So I am screwing around with the lathe, playing with different tool grinds, feeds and speeds to get that mirror finish everyone on youtube seems to get. I had a piece of 2 inch pipe 6 inches long that I slapped on the 3 jaw gripping on the inside hoping to get a good surface finish. First cut was OK meaning I could see the shop lights reflecting off of it, which is pretty good for me. So I regrind the tool and give it a little more radius and set up another cut at my slowest feed which is .0015 per revolution. Touched off and adjusted for a .001 cut and let her rip. It went about 1/8" with some smallish chips and then it started cutting without breaking a chip until I stopped it 1/2" from the chuck.

By my calculations I cut 5.25" roughly with a single wiry chip. I measured it and it is truly .010 by .015 inches in 1 continuous chip. If I am calculating correctly the chip should be right around 183 feet long.

I think I need to work on my tool grind some more to get the chips under control.

And just as a side note the surface finish is as fine as I have yet achieved. But that chip, damn.
 
No criticism intended but your work piece is a bit long to be cut unsupported by a tailstock center. This is made worse because you are holding it from the inside, which is not nearly as secure as holding it from the outside because the amount of stock engaged by the jaws is much more limited. Possibly having the piece come loose from the chuck is a real possibility. Moreover, deflection will be greater with a cut like this.

"Touched off and adjusted for a .001 cut and let her rip." ... "I measured it and it is truly .010 by .015 inches in 1 continuous chip."

Seems to me that something is off. You dialed in a depth of cut of 0.001", which should theoretically give you a reduction in diameter of 0.002" but the chip is 5 times thicker? Maybe you dialed in a bit more than 0.001"?

What I really intended to say is that the key reason for the long chip is due to a feed rate that is too slow. It also can happen when you take a very light depth of cut, so try increasing your DOC and feed rate and see what happens.



 
I think we might have some misplaced decimal points here. As Mikey pointed out, you're saying a .001" DoC gave you .010" chip thickness and .0015" feedrate gave you a .015" chip width. So, is the DoC .001" or .010"? Feedrate .0015" or .015"? And are the chip dimensions accurate in the OP?

Tom
 
That is very long. Some would use a stick or a long nose pliers to grab them because it is a bit dangerous and can damage tools. My lathe cross slide's mark is for diameter. So if I set 2 thous, it cut 1 thou.

Mirror finish is great.
 
Misplaced decimals. Cut depth was .010 and chip were .015.

I realize it is a bit long for that workholding method. Still learning and wanted to see how concentric it would be running that way. Was indicating less than .001 so ran with it. Looking for a bullnose center or to make one at some point.

Chip was clearing the work and tool and landing on the ground so I wasn't super concerned about it tangling up in anything.
 
A chip can easily compress while being cut, and would account for the increased thickness, especially if the tool does not have sufficient side rake to cut freely; as for record chip length, not even close! When I worked at Kaiser Steel in Napa Ca. back in the 1960s, George Apple, running a Colburn vertical boring mill with 5 ft. swing made a continous chip that stretched the whole length of our shop, 350 ft, it doubled over as it was being cut, and did not rotate, so he was able to reel it up as it was formed; this was on swing shift, I took it and stretched it down the center aisle for the day shift to marvel at.
 
MontanaLon said:
Chip was clearing the work and tool and landing on the ground so I wasn't super concerned about it tangling up in anything.
Click to expand...
How long was it in its natural state?

Tom
 
higgite said:
How long was it in its natural state?

Tom
Click to expand...
Don't know for sure, it landed in a pile on the floor that resembled a very loosely woven pot scrubber. I only measured the end to calculate the length.
 
We have made many wads of steel wool on occasion.

Sent from my SAMSUNG-SM-G930A using Tapatalk
 
Back in the old days (80's) when I was just starting at a shop we had a fellow run a curly chip down the aisle in the lathe department more than 55' long. I was told it wasn't his best work.
 
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