New traj planner

Hi Linuxcnc, I have a question relating to the new traj planner that was recently-ish implemented. In the video (see thread below) showing the improvement I note that the config is 500ipm - 30in/sec^2 and the new t.p runs at 400ipm. Am i correct in assuming that the limit of 400 is coming about as a function of the acceleration limitation (so increasing from 30in/sec^2 could theoretically get us to 500)? If not could somebody please explain to me what causes this limit?

Thanks 
Ant

forum.linuxcnc.org/forum/10-advanced-con...stersprograms-wanted

Hey everyone i thought I would add something to this in the hope of a kind expert sharing their knowledge. I’m currently using 2.54 and wondering if i should upgrade to mesa card to get the full benefit of the new traj planner? I use two parallel ports and gecko g540’s currently… lots of 3d tool paths with short segments. Thanks to anyone in advance for answering my perhaps poorly worded questions!

Thanks Tommy I will do as you suggest. Referring my other question about what limits the speed in the demonstration video for the updated traj planner to 400ipm - am I way off with thinking it’s the acceleration settings? I will try changing these when I have 2.84 up and running but keen to hear what others think all the same.

In the video here

forum.linuxcnc.org/forum/10-advanced-con...stersprograms-wanted

which compares the same spiral path with same config settings and shows the increased speed achievable with the new traj planner. I assume the increase is owing to the increase in look ahead allowing the tp to plan ahead and not have exact stops at the end of every segment. What I’m trying to figure out is what limited the speed to 400 ipm instead of achieving the 500ipm at which it was set. I.e is it that it can’t look far enough ahead to achieve the 500ipm on this spiral path or is it the acceleration setting or something else…

Thanks
Ant

Yes, if I try the arcspiral with my test setup (200 IPS/S accel, 20 IPS velocity)
It starts out at about 1200 IPM and gradually slows as the spiral radius decreases
due to being acceleration bounded.

Note that that spiral is only about 4" across so 1200 IPM is a bit crazy

Ok great thanks for the help guys.