Hello, I am designing a machine that will make grooves on round objects. Not a perfect groove actually, think of a sheave, so round profile. I have the attached formula for cutting power taken from below website: http://www.iscar.com/Products.aspx/countryID/1/ProductID/32 In my case, W=80mm, f=0.1mm/s. Vc=375m/min, efficiency I assumed as 0.8. If I take Kc as around 2000 (steel is St52), I get power as 98kW! Obviously it is not possible to use such a motor-gearbox couple in my paltry device. The possible problems: - Groove width of 80 is too big: but this is what I need. - Vc is too big: the round object is 800 mm in diameter, so even at average RPMs the velocity at the contact point becomes big. -Kc is too big: Actual Kc in my case will be much lower because I will preheat the material. HOwever I can't find specific cutting force vs. temperature chart. What can I do to find a reasonable power requirement? I have seen such a device with very small dimensions, so I know it is possible. I have limited experience with machining though.