Head vs Knee

[cobra]

Is there a view on the pros and cons of knee mill arrangement vs moving head?

 

[Krutch]

I take the query to mean Knee mill and bed mill. With the knee mill the head usually is adjustable by the ram, turret, ram knuckle, and the head swivels left & right. All these joints allow that type of mill to be quite useful, but makes it also subject to flexing while under heavy cuts. There is much which can be done with the typical knee mill. The work can be clamped to the table and the head tilted to many positions to mill, drill or bore at almost any angle. Work can be fixed hanging over the table and the head moved to access the work. For instance, end work on a shaft too long for the lathe or to mount directly to the table.
The bed mill has a more stable mill head in that heavy cutting pressures do not tend to move the head. Therefore the bed mill can hog out more metal per minute and one has not to worry about moving the head out of adjustment. Work that has angles to mill or other machining will have to be mounted to the angle needed on the bed mill.Most bed mills are good for production work where as a knee mill is for more of a variety of work.
I have two knee mills and though not US made, are good solid mills. I happen to like them. I do wish I had a bed mill, but get along OK with out one.
Hope that helps.



Those who have bed mill swear by them and the knee guys like their machines. It mostly depends on which one you use most often and for what machine work.