Hi guys, its been a while since I have posted / used my CNC for that matter.
Yesterday I designed and cut a bracket out of T6 Alum from a .25" thick stock.
The bracket is 0.125 thick so I used a pocketing operation to mill the top down to that thickness.
Here are my milling settings:
Cutter, 1/4" 4 Flute (
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1)
RPM- ~8,000
Feed: 30 IPM (maybe I should have done 20IPM?)
Tool Step over: 25% (1/16")
Depth of Pass: 0.0125" (10 depth passes to a final depth of 0.125")
Cut direction: "Mixed"
1- What is usually the cause of a high pitch screeching sound. At some point the cutting action would make a high pitch sound for a second(s). Most always at the same places.
2- What is the best way to minimize tool marks on the bottom of a pocket or face; or better yet what caused them? (see photos).
Here is a video, notice the screeching at the corners - I am guessing it doesn't like to "upcut" ? (which unfortunately you always either cutting one side of a parts interior features downcutting or upcutting.
http://[<a href="https://youtu.be/jg...U7cMKHgmQ]</a>