.060" Carbide End Mill = broken after second pass =HELP

[pdentrem]

This is using CNC mill.
I spin .020” at 60K rpm with a 30 ipm feed. This is not in steel, I am milling some special alloys. When I did some Platinum disks that are used in electron microscope, I did a minimum of 3 passes to get through the .030” thickness of the material and a slow 15 ipm (I think, my notes are at work). This is dry cut as recovery of precious materials is critical.
Pierre

 

[ErichKeane]

According to my FSWizard Pro (great F&S app for android btw!)you should be running it at 15k RPM, with a feed of 16.8 in/min. So you have to run it REALLY slow feed, really fast RPM.

 

[Janderso]

This is using CNC mill.
I spin .020” at 60K rpm with a 30 ipm feed. This is not in steel, I am milling some special alloys. When I did some Platinum disks that are used in electron microscope, I did a minimum of 3 passes to get through the .030” thickness of the material and a slow 15 ipm (I think, my notes are at work). This is dry cut as recovery of precious materials is critical.
Pierre

60,000 rpm!!!!
Holy schnikies. I can run at 5% of that speed

 

[tq60]

Your slitting saw got got.

For hobby, slow it way down.

Use oil can to apply oil.

Speed kills tooling.

Small carbide requires too much speed, you could put in a hand piece fixed in the mill, they call it a speeder.

But too expensive to play.

Sent from my SM-G781V using Tapatalk

 

[Larry$]

The advantages of CNC! On our router we run 15,000 rpm using a 3/8" end mill on aluminum. We cut oversized parts for the machine shop down the street. He provides the tooling and DOC & feed rates. Squirt bottle coolant. 40 HP vacuum pump.

 

[JimDawson]

I run those end mills at around 50,000 RPM. You are just not turning fast enough.

 

[MrWhoopee]

It's counter-intuitive, but you would probably have been better off with a HSS endmill. Lower speed and more flexible. Carbide isn't always better.

 

[twhite]

It's counter-intuitive, but you would probably have been better off with a HSS endmill. Lower speed and more flexible. Carbide isn't always better.

That and especially if you have any runout on that small of cutter to boot.


Cutting oil is my blood.

 

[pdentrem]

On these tiny bits, runout is so critical!
With .012” I have to reduce the feed to about 15 ipm from 30-40. We could upgrade to 100k spindle but major dollars above the already expensive 60k. You could go to an air spindle to get up in rpm. We did that for awhile.

 

[ltlvt]

I agree with Nutfarmer. I broke 2 of the .125 carbide end mills in one afternoon. Think that is why they sold them in the 5 pack. lol. This was only taking .050 DOC cuts at a time and sometimes even less DOC. That is why they call it Expendable tooling... lol