I also broke a 274-Z. It was the only one out of the 9 endmills I tested that broke under harsher cutting conditions.
Given the price of the Carbide 3D endmills, I’d recommend looking elsewhere. For the price of their ZrN endmills, you can easily buy a handful of decent DLC endmills somewhere else and I’ve found DLC to be fantastic with Aluminium. Nothing sticks to it!
If you want to go fast, you should also look into 6mm multi-flute endmills and an air blast. More teeth + same feed per tooth = more feed. You only want to use larger multi flute endmills though, otherwise chip evacuation is really hard unless you have flood coolant.
The rule I found worked well on the 883 Pro is:
- High RPM (I’d go 24k RPM on the Nomad 3)
- Conservative feed per tooth (e.g. 30um, or 720mm/min at 24k RPM)
- Around 60-75% radial engagement
- Start with around 0.1 x endmill diameter of axial engagement
Start with these settings then do test cuts. For each cut, increase axial engagement. Don’t touch anything else, especially don’t touch feed per tooth. Eventually you’ll reach a point where the machine sounds like a dying cat or the spindle starts to visibly slow down. When you reach that point stop and back off a bit axially until it sounds nice again.
You’d probably like someone to just tell you “cut like this” but it’s really hard to be able to do that. Different alloys, endmills, geometry etc. can complicate it. The most reliable way is test cuts.
Amana is mainly for wood from what I saw.