Why have a feed force in the cutting process?

[exln]

You knew there is a cutting force in the orthogonal process, it is exerted by cutting speed, buy why have a feed force?

 

[Baluncore]

The profile of the cutter has an effect on the force needed to feed the cutter into the cut.
A tool steel saw with positive rake may hook or pull the cutter into the material.
A carbide cutter with negative rake may be forced back from the material.
The increased use of negative rake requires stronger, more rigid machine tools with more powerful feed.
https://en.wikipedia.org/wiki/Rake_angle

What material are you machining?
What tool material and profile are you using?

 

[exln]

The profile of the cutter has an effect on the force needed to feed the cutter into the cut.
A tool steel saw with positive rake may hook or pull the cutter into the material.
A carbide cutter with negative rake may be forced back from the material.
The increased use of negative rake requires stronger, more rigid machine tools with more powerful feed.
https://en.wikipedia.org/wiki/Rake_angle

What material are you machining?
What tool material and profile are you using?

thank you, but you knew whatever the type of tool, there is no motion in the direction of feed force. If the rake angle equal to zero, is there a feed force?

 

[Baluncore]

There are too many different possible interpretations of the cutting geometry. The relative motion of the work and the tool in 3D have not been specified.

You need to restrict the discussion to a simple situation, such as a parting-off tool in a lathe. A zero rake angle would then have a low feed force while the edge was perfect. The moment the cutting edge became slightly dull or rounded, it would present a higher feed force, but it would continue to cut.