Big chip problem on a Vertical Turret Lathe operation.

[danielm]

Our machine operators are having a tough time dealing with big-long chips on a VTL roughing op. The chips are an inch wide and way too long and heavy for the chip conveyor to handle.  We're turning up to 80" diameter. The mat'l is 625 Inconel. 

 

Is there a turning insert that is specially designed to break chips....or another way to break them up?

 

Thanks!!

[crazy^millman]

Got live tooling on that machine? Mill the material off. If not might look at calling in your tooling vendors and have them give you some different inserts to try. With VTL's and that size of part when cutting that kind of material sorry to say kind of comes with the territory.

[K2csq7]

WG300 .375 button

600SFM .004"/rev 

CONSTANTLY vary the DOC..... 

 

As Ron said, it comes with the territory, but I was able to manage chips during large dia. roughing of superalloys. 

[jeff]

Got live tooling on that machine? Mill the material off.

 

Wouldn't that take quite a bit longer than turning it off? I've never used live tooling on a lathe but it seems like turning would be way faster.

[crazy^millman]

Wouldn't that take quite a bit longer than turning it off? I've never used live tooling on a lathe but it seems like turning would be way faster.

 

Nope. I think can take a .250 depth of cut 5" wide with a face mill. Trying turning that same amount of material off. Once pass around the part and I have removed .25 x 5" x 240" of material. Turning it you have to take a certain step over. Lets say you could get away with .02 per revolution at 9 rpm which is hot for this material. That would be 5" / .02 for a total of 250 revolutions. Using 80: diameter 240" is the circumference(yes I did not do exact to pie math.) That would be roughly 60,000 liner inches of cut verse 240 liner inches of cut. I think the milling would much faster than the turning would be. Also 6 or 8 flute face mill is dividing the wear on the inserts evenly among them were as a turning insert is only wearing on one insert. I have done some 10-2-3 Ti this way because the lathe operations were failing and taking 16 to 18 hours on a part. We were milling them complete in about 4 hours. We got different customers using VTL's with no live tooling and I think  we could cut their 12 and 16 hour roughing operations down to 2 or 4 hours with a milling operation. Finishing would be what it is, but we have a customer with a dual RAM custom made CNC VTL and what was taking 14 hours to make one part they are now making 2 in 12 hours.

 

Other issue with VTLs is they hate inconsistent material so that turning tool may have to cut a lot of air before getting into a good solid cut. The milling tool could care less and is more forgiving where as a turning tool will not like that.

[K2csq7]

Nope. I think can take a .250 depth of cut 5" wide with a face mill. Trying turning that same amount of material off. Once pass around the part and I have removed .25 x 5" x 240" of material. Turning it you have to take a certain step over. Lets say you could get away with .02 per revolution at 9 rpm which is hot for this material. That would be 5" / .02 for a total of 250 revolutions. Using 80: diameter 240" is the circumference(yes I did not do exact to pie math.) That would be roughly 60,000 liner inches of cut verse 240 liner inches of cut. I think the milling would much faster than the turning would be. Also 6 or 8 flute face mill is dividing the wear on the inserts evenly among them were as a turning insert is only wearing on one insert. I have done some 10-2-3 Ti this way because the lathe operations were failing and taking 16 to 18 hours on a part. We were milling them complete in about 4 hours. We got different customers using VTL's with no live tooling and I think  we could cut their 12 and 16 hour roughing operations down to 2 or 4 hours with a milling operation. Finishing would be what it is, but we have a customer with a dual RAM custom made CNC VTL and what was taking 14 hours to make one part they are now making 2 in 12 hours.

 

Other issue with VTLs is they hate inconsistent material so that turning tool may have to cut a lot of air before getting into a good solid cut. The milling tool could care less and is more forgiving where as a turning tool will not like that.

 

Not to disagree at all, every situation is different...

I have had a completely opposite situation with Nitronic... Milling 1 inch off the face was taking about 8 hrs... Turning did it in about 3.

The facing probably would have gone better on a more rigid setup vs. the old horizontal I was using (with 5' tall angle irons)!

 

It's all about the setup.

[crazy^millman]

I agree ever situation is different and every situation and application comes down to using what you got to get the job done.