Dynomotion

Group: DynoMotion Message: 8755 From: Hugh Sontag Date: 11/30/2013
Subject: Feed rate limiting by KMotionCNC
Hi Tom,

I guess a companion question is whether the movement in X and Y is limited to the values in the Trajectory Planner settings, as opposed to those that might be in the GCode. 

If a GCode program has an F100 (inches/min), and the X axis maximum velocity in the Trajectory Planner is 1 inch/sec, is the max velocity going to be 60 inches/min?

Thanks,
Hugh
Group: DynoMotion Message: 8756 From: Tom Kerekes Date: 11/30/2013
Subject: Re: Feed rate limiting by KMotionCNC
Hi Hugh,

That seems clearly to be a bug.  You didn't include the Version you are using or the starting Z position, but I'm able to duplicate the problem starting with Z=0 and the latest Test Version.  Please give me some time to look into it.

Yes all the Axis Velocity and Acceleration Constraints specified in the Trajectory Planner should always be honored.  However Rapids intentionally use different settings.  Also each should never violate its max velocity, but the combined velocities may be higher.  For example if both the max velocities for X and Y are 1 inch/sec then the combined velocity at a 45 degree diagonal would be 1.41 in/sec or 84inches/min.

Regards
TK

Group: DynoMotion Message: 8757 From: Hugh Sontag Date: 11/30/2013
Subject: Re: Feed rate limiting by KMotionCNC
I'm using version 430.

My observation is that the starting point doesn't matter, in that it'll happen even when the delta Z is quite small.

What seems to matter is the last feed rate that was programmed, which was generally intended for a previous X-Y move.

Hugh



On Sat, Nov 30, 2013 at 2:34 PM, Tom Kerekes <tk@...> wrote:
 

Hi Hugh,

That seems clearly to be a bug.  You didn't include the Version you are using or the starting Z position, but I'm able to duplicate the problem starting with Z=0 and the latest Test Version.  Please give me some time to look into it.

Yes all the Axis Velocity and Acceleration Constraints specified in the Trajectory Planner should always be honored.  However Rapids intentionally use different settings.  Also each should never violate its max velocity, but the combined velocities may be higher.  For example if both the max velocities for X and Y are 1 inch/sec then the combined velocity at a 45 degree diagonal would be 1.41 in/sec or 84inches/min.

Regards
TK