by cncdrive » Sun Jan 15, 2017 1:32 am
Don,
The axes moving with the feedrate you commanding them to move and the upper limit is the rapid feedrate set by the velocity parameter of the axis.
For example if you command X axis to move 1000 units/minute G1 X100 F1000 then your axis should accelerate up and move with 1000 units per minute speed and finally deccelerate down to stop on the X=100 coordinate.
Ofcourse I'm assuming here that your axis is far enough from the X100 point to be able to accelerate up to F1000, otherwise if the distance is shorter then the axis will accelerate up to half of the way and deccelerate down from halfway to endpoint without reaching the end-speed.
I'm also assuming that the axis has an equal or higher Velocity parameter than 1000, otherwise if the velocity parameter is lower then that is the upper limit and that will be the limit in the feedrate for that axis, so the axis in this case can't reach the F1000 feedrate.
And if you commanding 2 or more axis then they run together, for example G1 X100 Y200 F1000, then X and Y will run with speeds to reach the programmed point the same time, so there is only one case when they will run the same speed if they are the same distance away from the target point, because then they need to run the same speed to reach the endpoint the same time.
In all the other cases the 2 axes will run with different speeds, otherwise the movement was not linear.
And in all cases the programmed feedrate F is the feedrate on the movement vector and not on the individual axis.
There is one case when the axis feedrate is the same as the programmed feedrate is when only one axis is commanded to move, because then the movement vector lays on the axis.