Curious corner cutting

[tomgardiner]

It took me a while to get my head around this.
I was cutting a series of nested frames from sheet goods a while back. The toolpath was profile outside of vectors. All right angle corners. What I noticed was the cnc came into some corners and made a slow dwell at the apex and then resumed cutting while in other corners the transition was quicker with little to no dwell.
I watched the file scrolling by on the control screen and noted the code was a different format for some corners. The light bulb went on when I realized the difference was inside corners to outside corners. Inside corners coded as simple X-Y coordinate moves but outside corners incorporated I-J radius.
I know the machine control is responsible for the acceleration decceleration but I was perplexed until understood how the program addresses outside corners by having the head cut a radius equal to the tool radius. I'm guessing the Fagor control has more aggressive acceleration based on the size of the radius. And effective zero radius slows the machine to a crawl through inside corners.