Speeds And Feeds Question

[WalterC]

This video source has been a great help to me. The videos on chips, feeds and feeds might echo some of what has been said here but it has more explanation on choosing speeds, feeds and depth of cut.
http://www.thatlazymachinist.com/my-shop-videos.html

Thanks- good source of information.

 

[Tozguy]

Walter,
Yes, that video seemed to be just the right amount of info that I needed at the time. In case it might help someone, these are some quick reference notes kept handy for when I loose my way.

Notes from M. Lecuyer’s videos on chip control:
Factors: Speed, feed, depth of cut, tool angle.
Speed:
Speed is generally chosen according to the material used and the tool material (HSS or carbide).
Can be found on speed charts from many sources but these are always maximums. Start at 2/3 of listed speed and work up as feels OK. General guidelines for the hobbyist:
· Mild steel = 100 fpm Too slow = discontinuous chips.
· Med. Steel = 70 fpm Too fast = built up chips or adherent
· Hi carbon = 50 fpm Proper = continuous chips
· Aluminum = 300 fpm
· Brass = 200 fpm
· Bronze = 80 fpm
For carbide X4
Feed:
Feed is generally based on the finish required. Finer feed equals finer finish.
Depth of cut:
Depth of cut is usually set to get the right chip formation and color. Aim for continuous and curly (tight) chips that are shiny on the outside and matte on the inside. With a HSS tool the chip should be white to slightly yellow (400*). With carbide tools, the chip should be slightly blue (600-650*). Dusty small chips and chunky built up chips are to be avoided (hard on tool life and vibration affects finish). Low depth of cut will never give a good finish.
Angle:
Softer materials accumulate better, need positive rake and less heat generated in the chips to avoid welding.
Harder materials need negative rake to accumulate more metal so that metal heats up and softens. More power is required.
Roughing = deep cut, fast speed, small nose radius
Finishing = moderate cut, slower speed, large nose radius.

 

[barrydc1]

Here's another very simple approach that I use now because he explained it in a way I could grasp.