Running large 3d code in linear interpolation mode (G1)

[ArtF]

Hi F:

  The planner is a work in progress, as you know Tempest sat for a long while used only by
those with heavy gantries primarily.  Im still working on it to see if I can smooth it out,
but its very specific to use, small line segments still can make it twitchy, but we'll see what happens
over time.

:)
Art

[chicoxiba]

Art

I imagine that it is a big ask, I remember you writing that the maths behind tempest is scary. I have kind of followed it since the beginning and have read most forum threads i think. Even downloaded docs on trajectory planning from google.. yes, right over the top lol. The main reason I started chasing these avenues is that I saw mach3 didn't have symmetrical accel/decel ramp during G1 (I do have a heavy load for not so powerfull motors). The accel respected the motor tuning curve but the deceleration was always quite abrupt and short, still is. On version 3.043.022 Brian did make the accel/decel symmetric for me, although there are 2 other imperfections he said he would fix it but in m4. I use it a lot and it works fine, I can get good job cut times out of it.

Since then I have tried many different controls. To my surprise the chinese pendants do a brilliant job maintaining CV versus cutting true to the path (bangbang tp). But I still like to have the computer and not have to be carrying files around on a flashdrive, nice toolpath display, customizable and way more fun.

In saying that I have never known an Scurve acceleration motion controller that works good apart from those million dollar machining centers. It would be SICK if you were able to get it there.

Thanks,
Francisco

F

[ArtF]

Hi F:

  I think I will do a write up on how tempest works so everyone has a chance at
understanding the why's as to its strengths and weaknesses..


Art

[chicoxiba]

Art,

Heres something I came across a few days ago and I remembered you. This guy improved the TP for linuxcnc recently. I have never seen it in action.

https://www.youtube.com/watch?v=412N5A-N8Fc

F

[ArtF]

Thanks for the link,

I havent followed EMC for a long time in terms of its code, but I have to say I could almost
copy that video as a primer on the Tempest planner. Not the same, exactly, but close in many ways
and I can hear, as the lecture continues, many of the math papers I read in developing tempest.
 
    It really shows in soem depth just how much there is to a planner, how they are a rocket
science of their own and a facinating puzzle to play with.. and I suspect each players puzzle
shows a somewhat different picture in the end.

Art