Milling aluminum brackets (First time milling aluminum) 

Great work! The only thing I could suggest is to clamp the spindle much closer to the bottom instead of the middle of how you got it. I see you’re bottoming out your Z rails travel to reach the stock so stacking up a bunch of small sheets of spoilboard to make a raised work area for small tools like his helps them reach the bottom. Also saves your spoilboard if you happen to be milling a lot of things and want to mill into the spoilboard so to get a nice clean cut all the way through to the bottom. Small parts like that can get sketchy if the tape will hold them down on the last pass of slotting them out. On parts that have holes in them. I find it best to mill/drill the holes as the first op and than use those holes to screw down the part so it doesn’t go anywhere while you slot it out. Other than that try ramping into the slot at the start instead of plunging, It’ll be less hard on the tool as you can tell by the crushing sound it makes when it enters.