Too fast or too slow?

[OTmachine]

Forget about the book on feed and speeds. Every machine, tool holder , tool length, coolant type, endmill quality IS different. If you are on BP mill try 600 rpm for HSS and about 1400 for carbide.

What about tool / work diameter? Need to figure S.F.P.M.. Just sayin’

 

[Fasturn]

I have watched many times where a cnc mill will run fast and take small cuts and hog out metal.
I also watched a cnc mill take a super deep cut while running fast and slower feed.
While I am sure your experience is a thousand times more than mine, I have seen it in videos. I have also started using higher speeds and faster myself. So, I don't understand.

Well they now do dynamic milling. The prior art was slow with large DOC. Today a 1/2 EM carbide would run 3000 rpm and .012 per pass. Around 50 IPM feed. Idea is small bites and not load up the cutter. Looks great, but kind a like the tortoise n the hare. It does have a place at times. Morphing is another type of cnc milling. This is with fire hose coolant and ridged spindle. BP mill , ya got to slow down. The new ( high quality endmills ) are pretty amazing with aggressive milling. The machine and the cutter will let you know what it can do and can't.

 

[Fasturn]

What about tool / work diameter? Need to figure S.F.P.M.. Just sayin’

I know... I am from the rpm / ipm time.
I can just look at the spinning endmill and say " good start". The divider on ipm turns it up or down and will take me about 4 seconds to match chip loading. Every machine ( size ) will be different. Same with drills n reamers. Now in very high production !!!! Tool brand suggestions are important. Hard to convey old school knowledge to the SFPM guys. I did prototype and tooling most of my life. The owners didn't want to kill a Machine in 2-3 years, so we were pretty conseritive on feeds n speeds. Now a hobby guy needs to be more conservative, endmills n machines don't come cheap ??

 

[epanzella]

I'm no machinist just a guy who has machines to keep his other machines running. The power feed on my mill drill has no real numbers on it so I conservatively pick my speed from a chart. Then I make my first cut shallow (like.030) while playing with the feed until the chips look good and the machine sounds happy. The next cuts determine how much DOC I can get away with. It goes kinda slow but trashing a $50 cutter to save a few minutes is a sad day in my shop.

 

[RaisedByWolves]

I have watched many times where a cnc mill will run fast and take small cuts and hog out metal.
I also watched a cnc mill take a super deep cut while running fast and slower feed.
While I am sure your experience is a thousand times more than mine, I have seen it in videos. I have also started using higher speeds and faster myself. So, I don't understand.

Do you have the same equipment and experience as those who made the videos?

How many times did they do it wrong before they hit the send button to post thise vids?