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End mill chipping

That sounds like it shouldn't be a problem. From everything I'm getting from you, unless I'm missing something, this should be an easy cut. What are we missing? Can you post any pics?
yeah its really sounding like they have crashed the macheen :scratchchin:
waiting for diagnostic feed back:toetap:
How much play do you have in the tool assembly?

What I'm really getting at is inside the turret there is (usually) a female keyway for the male drive key in the milling drive. Of there is too much play, on a channel cut the drive key alternates between push and pull... similar to what happens when you climb cut on an old manual mill.

You mention it may have been crashed... make sure the drive key in the turret is still within spec.

Of there is too much play, on a channel cut the drive key alternates between push and pull... similar to what happens when you climb cut on an old manual mill.

It sounds like you're talking about a key on the shaft that transmits power to the live tool. Like the flattened tang shaft or the male spline on the tool side.

I think you're saying that backlash in this rotary drive coupling can cause excessive chip thickness similar to climb cutting on a mill with leadscrew backlash where the tool suddenly climbs into the work when the linear axis slips.

I'm not seeing how rotary tool drive backlash could cause that kind of thing. Please explain. Do you mean some other key?
Correct. You explained it much better.

There's supposed to be almost no play when you have a live tool engaged. If there is play and you're channel cutting, the cutting forces push and pull. That "could" cause chipping. Like others have mentioned excessive runout of the tool, the milling holder may be due for a rebuild, the collet could be not gripping on the tool properly, the cutting parameters could be incorrect.

It could be a combination of all or some of these, or ot could be something entirely different. Just offering something additiona to look at.
Haha really sorry I missed the crucial part. I am cutting stainless steel, 316.
The radial depth of cut is 0.5mm.
tool stickout, length of tool holder, rigidity of part, fixture or holding setup have large effect, literally
you can reduce tool life easily from vibration to only minutes. obviously tool/tool holder gage length
of 500mm compared too 50mm gage length obviously have different vibration limits. some parts
and work holding setup vibrated more than others. for example part 1500mm above table compared to
100mm above table have different vibration limits
stainless 316 I would ask is it cold rolled or workhardened as compared to annealed. workhardening
from rolled plate or drawn bar can reduce machinability 100 to 400%, some stainless has larger slag inclusions
or hard spots that can be abrasive on tooling causing tool life of less than 20 minutes. I have seen
hard spots damage 6 each separate tools in 1 second each. Pictures show bigger slag inclusions, coolant
or cutting fluid helps with bue or built up edge that is chips sticking to cutting edges, some chips breaking
free take pieces of cutting edges with them. harder materials often have to go easy on depth and width of cut
too much just chips the cutting tool edges
obviously if somebody gives you recommendations and endmill goes red orange white hot melts in minutes
take the advice with some skepticism. most have a tool database of standardized tool holder and tools with
tolerances on tool stickout, tool database can have a range of feeds and speeds with harder materials
being machined noted compared to softer materials and some settings for parts that vibrate easy, its
not always the tool and tool holder. some parts/ work holding setups vibrate easy
also some tools when going dull vibration can increase 100 to 1000%, 4th picture shows vibration
pattern of mill with inserts going dull and vibration resonance can randomly happen, if getting
mirror surface reflection as shown obviously vibration is under control


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A few questions for @Black_mamba:

Have you checked for radial and axial slop in the live tool by trying to wiggle the tool (or an equivalent rod to avoid getting cut)? A bunch of people have asked this, but I don't see the answer.

Have you checked for radial slop of the workpiece? Maybe the chuck jaws are bellmouthed, chuck is at end of travel, collet is wrong size, or something else is going on that's letting the work move.

How does the cut sound: chatter?

Is there any point where the tool isn't spinning while it's touching the work?

Are you sure that the tool is spinning the right way?

Like others have said, a few pics of the cut surface, chipped cutter, and the setup would really help.