gang milling

[Thoob]

Hi all. New to the forums and was wondering if someone could help me out. Its about gang milling. If I have 3 different diameter cutters on the arbor, how to I calculate the speed? Do I use the largest cutter diameter of the 3? If so, how would I calculate feed since the chipload would vary from each cutter cause of speed. Im kinda lost on this one. Searched around google but nothing actually specifies what calculation to use. I mean if I took the biggest cutter (3.0") on mild steel 100x4/3 = 133 rpm now that would make the 1" cutter also spin at that rpm but if I use the same feed wouldn`t that damage the 1" cutter cause of too much load?

[HuFlungDung]

Yes, the largest diameter of the cutter in use takes precedence, because that is the part that is going to overheat if you run it over rated speed. Once you have determined that, then of course, the number of teeth, and their rated chipload, belonging to that cutter, controls the maximum feedrate. However, other cutters in the same gang that cannot handle such a high chipload will have priority over chipload as well.

The biggest controls the speed, and the weakest controls the feed

[Thoob]

cool. thanks alot.