CNC Tooling

[Cory]

Originally Posted by techhelpbb

At this link...
http://www.daycounter.com/Calculator...lculator.phtml

Plug in 0.25", 300SFM, 3 flutes.
You get: about 4,500 RPM, 27.5 IPM
Makes sense that this works.

Plug in 0.25", 1,310SFM, 3 flutes
You get: about 20kRPM, about 120 IPM
This is probably not going to work.
I would be a bit suspicious of a carbide end mill rated at 1,310SFM uncoated.
Even more suspicious if your router can sustain the feed rate to keep it from rubbing.

At a spindle speed of 20kRPM I think you should consider a TiAlN end mill for the router with 2 flutes and 1/8" diameter.
That would get you:
655SFM, 20kRPM spindle speed, 80IPM feed.
If your gantry mill is outfitted with either really powerful steppers or servos it will work.

1300 SFM is perfectly reasonable for uncoated carbide. Most vendors will recommend 700-2000 SFM for a carbide end mill with aluminum specific geometry.

TiAlN, AlTiN, and TiN are always bad for aluminum. They have an affinity for aluminum which leads to galling, causing your end mill to load up and break.

While you are correct that TiAlN and AlTiN are designed to perform best at elevated temperature, you could never even get them to that elevated temperature in aluminum as you would have to run without coolant and you would be guaranteed to melt your chips and pack the flutes long before getting up to temp, completely disregarding the fact that these coatings are not advisable in aluminum due to their physical properties.