Hi all,

Bit of a weird one, this - I noticed it a while back, but using mainly smaller tools and cutting at pretty slow feeds it hasn't really bothered/affected me. I quite fancy getting to the bottom of it though...

The issue:

If I generate a tool path using straight lines at at a feed of 1800mm/min the machine runs at 1800mm/min - this is true regardless of whether those straight lines are horizontal/vertical (using only one of the motors) or diagonal (using both the X&Y motors).

If I generate a tool path where there are radii present the machine slows to around 1000-1100mm/min (it fluctuates) when it hits the corners.

Here's an illustration using three distinct shapes. Each shape has an identical path length and the CAD software reported that each scenario would take the same time to cut, but check out how everything slows down when cutting the circle.



Weird, huh? Machine is pretty beefy and happy at 2400mm/min rapids (well beyond that even, but I don't..)

Here's a real world example where you can clearly see the speed discrepancy between the 'straight' and 'curvy' bits of the cut:



Probably a simple solution to a dumb question - anyone..?

Wal.