[tool-nose]

Hey guys, been watching and reading this forum for a good while now and have learned some things from here. This is my first post so lets see how this goes.

We are machining Inc.718 on a Swiss. Running some test on the tool life.
Getting around 1000-1500 pcs per cutoff insert, but every every once and a while the insert will fail (explode) well before 1000pcs. Is this jusy the nature of the beast (Inc 718) or is there something I should be looking for?

[ProProcess]

I think you should be really jazzed about getting that type of tool life in the first place!

As for the catastrophic failures...

Insert seating in the holder
Oil line placement/movement
Errors during setting that cause small chips in the insert
Abnormal barØ that cause excessive loose or tight guide bushing conditions.
Hard spots in the bar (the worst!)

[tool-nose]

Thanks pro-process, I am jazzed about the insert life, but new management (young college guy) thinks that this insert failure can be fixed. I've been machining these parts and others from Inc.718 for around 15-20yrs. And have always had a problem with cutoff inserts failing early. I've actually hade inserts fail back to back, change the bar, inserts run fine. Tried explaining this to him, he seems to think it's in the program or something else. So again thanks fro the info..........

[Fabitfast]

This blog might help you in cutting Inconel 718: How to Best Cut 718 Iconel | BandSawBlogBandSawBlog .

[SirDenisNayland]

I love the bandsaw attachment I rigged in my swiss machines

[danrudolph]

With the insert life you are getting, I would focus on detection of the random failures.

Do you have cutoff tool breakage detection on your machines?

[gizmo_454]

Material variation can really suck from time to time. We have run jobs where, like you mentioned, after a bar change everything goes to h3ll in a hand basket. Change to another bar, and everything is good to go again.

Do talk to your tooling rep. You know the one I mean. Not the distributor, the guy who actually works for the company whose tools are in the machine, ie: Iscar, Mitsubishi, Kennametal, etc. They may have a suggestion as to a different grade, and/or chipformer that may help the situation. We have a few jobs in 316B (27 HRc) and I have had a similar issue to you. Some cutoffs last several hundred parts, some last 2. Moving to a stronger chipformer didn't gain me anything more than the several hundred I would occasionally get before, but at least made it consistent and somewhat bearable.

Good luck!

Mike

[Ned-Dragon]

Did you tried use G75
If insert gets bad after 1000 parts, I wouldn't worry about it.
What is size of material and what swiss lathe?

[tool-nose]

What is G75 ??
I'm not the one that is worried, that would be the college kid...........
This is being done in a citizen L20 using 9/16 dia barstock.

[Ned-Dragon]

The Fanuc G75 grooving cycle has multiple parameters, which can be set according to your needs.
Star Swiss lathe:
X.62
G75R100(R IS HOW MUCH TOOL WILL RETRACT AFTER EACH CUT)
G75X.08P100F.00000
G0X.08
G1X-.03F.0000

OR
X.98 Z2.
G75R100(R IS HOW MUCH TOOL WILL RETRACT AFTER EACH CUT)
G75Z2.505X.605P100Q1000F.0000(IN THIS CASE IT WILL ROUGH MATERIAL ON "Z" TOO)
(Q IS STEP OVER AMOUNT IN Z)


CITIZEN
G0X1.05
G75R.005
G75X.32P.015F.004

OR
G0X1.05 Z.73
G75R.005(R IS HOW MUCH TOOL WILL RETRACT AFTER EACH CUT)
G75X.5Z.86P.015Q.1F.004(IN THIS CASE IT WILL ROUGH MATERIAL ON "Z" TOO,)
(Q IS STEP OVER AMOUNT IN Z)