Endmill failure or wrong feeds and speeds?

[CNCOlly]

Hi,

I'm trying to pocket into 40mm oak to make a key tray. My first attempt worked fine and then I did a redesign and when cutting the bit failed. I was filming the cutting so I thought I would share it with you to get opinions on what went wrong.

My thoughts are it was a mildly blunt cheap old endmill. I think the feeds and speeds were correct for the size of the endmill just not the quality of the endmill.

These are my setting

Feed rate 4000mm/min
Spindle Speed 18000 r.p.m.
Pass depth 5.96mm
stepover 40%

This is the endmill

https://www.screwfix.com/p/erbauer-s...B&gclsrc=aw.ds

And here is the video to see what you make of it.



My thought are should I buy a new cheap endmill of the same type and reduce the feed rate a bit and try again or buy a more expensive endmill?

Regards,
Oli