Personnel from Boeing's Research & Technology group recently answered readers' questions. One reader asked the following. To see the list of experts taking questions from readers right now, see our Ask An Expert page.
I recently have been involved with the acquisition of a new milling machine. It is a large 5-axis gantry-style mill with a nutating head. This head is A-axis swing and C-axis rotation. Travels are 200 degrees for A and 400 degrees for C. I want to have the head modified to unlimited C-axis rotation, though my managers question whether we can justify this request. What is your opinion?
Response from Boeing’s Research & Technology group
We have three machines with the same 400-degree C-axis limitation, and from a programming standpoint it can be challenging. When we program 5-axis pocket and periphery motion, the head hits the limits often enough that it requires added programming time and machine time to repeatedly “unwind” the head.
Our opinion (though we have no hard numbers to back this up) is that unlimited C-axis rotation would pay for itself in reduced programming time and increased machining efficiency.