So this is the case that I am milling out of EcoCast.



These are the end mills I have so far.
3.175mm http://www.ebay.co.uk/itm/1824106825...%3AMEBIDX%3AIT
2mm https://www.aliexpress.com/item/10pc...608.0.0.EJZ3Jx
1mm https://www.aliexpress.com/item/10pc...608.0.0.EJZ3Jx

The case is like 75x60mm so I don't want to carve that all out with a 3.175.

Was thinking of getting something along the lines of a 6mm end mill to do the main hogging out.

What is the max these spindles can take?
I have collets up to 12mm.


Also, where is the best place to learn speeds and feeds? I have been testing these 3mm on a bit of this EcoCast and broke 2 end mills within minutes.
One I accidentally knocked into the work piece. The other because I did not know how to correctly set up the Z in Fusion CAM.