Always breaking parting tools

[MrWhoopee]

I use carbide tooling for everything on my lathe, EXCEPT parting.

My keys to successful parting:
1. Sharp tool, as short as possible
2. Tool on center or a whisker below.
3. Keep the feed rate up. If it chatters, feed harder. Keep a nice curl going.
4. Lubrication is important, get the cutting fluid down to where the cutting is happening (gets more difficult as the groove gets deeper).

When I had the business, we gave up on inserted parting tools. Every crash resulted in a trashed blade as well as insert, it just got too expensive.

 

[great white]

I use carbide tooling for everything on my lathe, EXCEPT parting.

My keys to successful parting:
1. Sharp tool, as short as possible
2. Tool on center or a whisker below.
3. Keep the feed rate up. If it chatters, feed harder. Keep a nice curl going.
4. Lubrication is important, get the cutting fluid down to where the cutting is happening (gets more difficult as the groove gets deeper).

When I had the business, we gave up on inserted parting tools. Every crash resulted in a trashed blade as well as insert, it just got too expensive.

Same. I like inserts for everything except parting. Its not that I can’t make my own hss cutters, its just a lot easier to replace/turn an insert and keep going. I do try and avoid interrupted cuts with inserts. I find they chip too easily on the interrupts and I have to replace them more often than I’d like.

Same experince with crashes with carbide parting tools. When it goes wrong, it goes wrong big time…

 

[Winegrower]

What helped my parting was two things: First, I got a heavier and more HP lathe, and second, advice from Mikey and got an Aloris 71 parting tool and holder with GTN3 inserts. I still find that running the X axis by hand is best, watching the chip and keeping a constant curl coming off. I have not hack- or band-sawed a part off for a long time now.

 

[Manual Mac]

After many years, my biggest breakthrough with parting has been upside down rear parting.
many threads on this.
i can thank Mikey and others for finally convincing me.

 

[taiwanluthiers]

After many years, my biggest breakthrough with parting has been upside down rear parting.
many threads on this.
i can thank Mikey and others for finally convincing me.

I had done that when I used to have a PM-1228LB because that lathe can't part steel directly, and upside down parting worked. But I just figure the Victor would work much better considering it's like 4 times the weight...

 

[great white]

I had done that when I used to have a PM-1228LB because that lathe can't part steel directly, and upside down parting worked. But I just figure the Victor would work much better considering it's like 4 times the weight...

My th42 atlas parts 1018 easily and thats only around 300 lbs. its not weight that matters, its rigidity.

As I mentioned, my biggest improvement with parts came when I ditched the top compound and made a steel plinth direct to the cross slide.

 

[AGCB97]

See post #32 in this thread

Another Parting off Thread

I guess I'm confused with terminology, I was thinking the blade and the part had to be exactly parallel on the face, as in no tangents. to cut straight. That would make them perpendicular.

www.hobby-machinist.com

 

[wachuko]

See post #32 in this thread

Another Parting off Thread

I guess I'm confused with terminology, I was thinking the blade and the part had to be exactly parallel on the face, as in no tangents. to cut straight. That would make them perpendicular.

www.hobby-machinist.com

I recently saw a video of someone using a setup like that... he even had a guide/slot on the bottom plate to minimize any side forces issues...

 

[wachuko]

Found it... it was from Winky's Workshop channel... you can clearly see it at 26:06

But he also made another one cutting from under...

 

[rabler]

Are you using wood veneer shims below your parting tool as you discussed in your tool post thread?