On 13 September 2010 10:51, Spiderdab <77...@tiscali.it> wrote: > than, as Brian suggest is interesting, but i really cannot know the > formulas of the arcs i'm drawing. > also writing by hand the acceleration like g1 f100, g1 f150, g1 f220, g1 > f400.... you know, the show is like 5 minutes of a volleyball doing > maybe 80 arcs in the air!! cannot write all by hand!!
It's fairly simple mathematics. Excel can probably do it, (using the goal-seek algotithms). In flight the path of the ball is governed by well-known ballistic equations. Given a start-point, velocity and launch angle and an end-point the rest is a simple piecewise calculation. I think it is worth getting it right, as I suspect that we have a much better idea of what objects in flight behave like (or we could never catch them, or hit them) and if the trajectories are unrealistic I think it will detract from the effect. I was about to start on a spreadsheet to generate ballistic trajectories as G-code, then remembered that I am at work and paid to do other stuff. When do you need this project working? > 1) immagine the ball flyng at 30mt/min in one direction, and then > suddenly the direction become opposite. the ball bounces for the > 'impact' (sorry for my poor english..) and the stepper motors loose some > step. This is the reason that EMC defines a max accelleration in the INI file. You should be able to set this such that you never lose steps. > 2) tryed to use in the .ini file a slow acceleration, but using that it > return me error when i jog in world mode. i realized that the slower is > acceleration, the slower is the jog speed that i can reach without > errors in world mode. This happens when the STEPGEN_MAXACCELL is lower than the MAX_ACCELERATION in the INI file. Generally the stepgen should have a higher number than the max_accel. I think you need to set these values to the actual physical maximum of the axes (with a bit of overhead) and the control the trajectory with feedrate. -- atp ------------------------------------------------------------------------------ Start uncovering the many advantages of virtual appliances and start using them to simplify application deployment and accelerate your shift to cloud computing http://p.sf.net/sfu/novell-sfdev2dev _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
