Strange Swarth

[PeterT]

Your chips are indicating very hot. The odd one might bounce a few feet but if its spraying 4 feet, that crazy. Are you still at 1000 rpm like post #1 or have you since reduced speed? Dumb question but are you sure its 1000 rpm? Maybe a different sheave combo was swapped on the drive line or motor was replaced with another at some point? Same slug of plain 1018 so not mystery metal. Swapped the cutting tool, tip is centered... I'm running out of ideas. Have you tried another piece of steel with the same setup & you get the same results or these issues came about with this particular slug?

 

[YYCHM]

Ok, I lied. Was running more like 500 RPM according to my lathe face plate and belt setup. Will check it with my optical RPM meter tomorrow. Same material. Still.... a very radical change in behavior.

 

[Johnwa]

I switched to an indexable carbide tool.
Got pelted by this stuff. It was thrown a good 4' from the lathe and hotter than blazes. Had to dawn lather gloves to finish the cut as my hands were being bombarded with hot shrapnel. Was picking fragments out of my hair, shirt pocket, still finding fragments here, there, every where.

I'm liking the long stringy stuff better

Been there, and I agree stringy stuff can be better LOL
I tend to use HSS partly because of that. I still haven’t quite figured out how to grind a chip breaker but usually I don’t get the real long strings so it hasn’t been a problem. HSS allows you to take way finer finishing cuts as well.

 

[Tom Kitta]

This is more or less what I get when cutting on my lathe with carbide. Yes it burns holes in shirts and yes it can throw into hair once in a while. Color is the same as well. Remember that blue as per color chart is around 300C which is not a big deal for carbide cutter - the swarf is what is taking the heat away from the piece you are cutting. Yes if a large piece lands on your hand it burns.

Some metals are worse then others - I get burned hands more with hard stuff - say turning 4330 vs. 1018.

I also get very hot - even more then blue, like red with dull carbide - change tip and try again. Are you sure it is 1018? If its some cheap stuff it may have hard spots.

 

[YYCHM]

500 RPM according to my optical RPM meter.

 

[kylemp]

I switched to an indexable carbide tool. Same stock, same speed.

View attachment 6934

And got this.....

View attachment 6933

Got pelted by this stuff. It was thrown a good 4' from the lathe and hotter than blazes. Had to dawn lather gloves to finish the cut as my hands were being bombarded with hot shrapnel. Was picking fragments out of my hair, shirt pocket, still finding fragments here, there, every where.

I'm liking the long stringy stuff better

Those chips are closer to correct.. Long and stringy are very dangerous as if somehow they manage to get ahold of you they'll rip you apart. The whole function of a chipbreaker is to get tight curls that break into small pieces, ideally 1in or less so that they can't get wrapped up in the chuck and thrown as a birds nest or get ahold of you. The lathe is going to throw them to some degree, if it's that big of an issue for you build a guard to protect from flying chips.

 

[Dabbler]

Still a little fast in the SFPM range. Efficient turning is going to get u pelted by stuff. I recommend a leather welders apron with regular work gloves. Last week I got a small burn on my neck (tender!)

 

[Brent H]

 

[YYCHM]

Nice setup!

Is that your machine Brent?

Craig

 

[Brent H]

Not my machine but looks like something you can make. Cutting the stuff like 4140 etc will make bloody smoking hot chips and they fly around like crazy. The lathe on the ship has a guard like it.

 

[YYCHM]

Ok, today I experienced first hand why long stringy swarf isn't the best thing to have happening. As pointed out earlier by @Dabbler

Just as I was completing a power feed cut, this birds nest erupted out of no where flailing around at 500 RPM. I was so startled I hit the ESD.

 

[Janger]

If you pulse the power feed on / off then the chip will break off. Surface finish may sufffer. I love it when the birds nest flies out of the chip tray and whacks you in the face. I've had a near miss with that... learning learning... I see I made exactly the same comments last year. I'll shut up now...

 

[Brent H]

That is quite the impressive piece of art you have going there Craig! Interesting how you were able to pile the chips up so high - well done!

Looks like your lathe is leaving a good finish on your part though.....just have to dial in the speed and feed and cutter chip breaker to get things breaking off nice - some materials will always be a pain and you just have to keep the long strings clear of the tray and the chuck jaws - sometimes involves lots of start and stops! I especially get annoyed when you are approaching a stop and you are watching to stop the feed and then the big string wraps around so you can't see ...frustrating!

 

[Tom Kitta]

Depending on insert and metal cut and depth of cut and feed the chip breaker will make it all into tiny chips. Usually chip breaker works with a bit of a deeper cut - like say 40 thou per side. Finishing cuts to size frequently create lots of nesting. So to limit the nest, if possible, do heavy cuts and one final cut.