[Fawaz CNC]

hello, my problem with 4th axis(A-axis), the time calculated by HSM Works in 4 axis machining is less than the actual when machined on my CNC milling machine using Fanuc control system. the difference in time is so far (Actual machine time = 2.77 simulated time), is there any body can help me with this problem??

[peteeng]

Hi Fawaz - The cam system uses the programmed speed to calculate the run time, even around corners. But in reality the trajectory planner slows down the machine around corners. So if the program has lots of corners or changes in trajectory the actual run time is much longer than the calculated time. No way around this really as the CAM system does not talk to the planner and vise versa. If the path is majority straight the run times will agree. Something you just have to live with and by experience adjust to. If you can preview or pre-run the code in your controller this may calculate your run time more accurately. But if its a long program this may not be convenient. Peter

[deadlykitten]

hy fawaz besides what peteeng replied, another cause may be feed calculation when rotary axis are involved, as they sometime are <> linear axis

for example G1 Z10 F100mm/min and G1 A10 F100mm/min may have different real execution times, in a fraction of 1:2 2:1 1:10, etc, depending on pivots, etc

such formulas related to rotaries may have a bigger impact on simulated time inacuracies

if you wish, i can try to guide you through it, to find the cause / kindly