Lathe, Max. load in chuck, betwen centers and spidle speed

[engjmb]

I am an electrical engineer that I have received the order of calculating the capacity of load of a lathe. I have realized the calculation considering the life of the bearings, but I obtain values very high of capacity. I would want to know that criteria can apply to obtain a few safe results.

Thank you

 

[ornerynorsk]

Almost all manufacturers have their "advertised" maximum workpiece weights and corresponding rpm's. I would imagine that most machines could far exceed their advertised capacity if you were to calculate using bearing capacity alone, but remember, the instant a toolbit hits the workpiece, the calculation changes. RPM is another story. You can have a very heavy seemingly balanced workpiece turning just fine at, say , 350 rpm, but bump that up to 500 and the machine might start vibrating like crazy. The weight and footprint of the machine have a lot to do with its practical capacity as well.