On 02/13/2015 11:33 AM, Horváth Csaba wrote: > Hi, > > This is the first time I try to set the gantry mode on a machine (XYZX). > I cast a lot on the object related to these following errors, but I > couldn't find any solution. > > I have 2 major problems with the gantry machine: > 1. In World mode I get the error ""joint 2 following error". This error > also come up when I transcribe Ferror and Min_ferror for a high rate. > Until I move jogging mode Z axis into either direction the Ferror rate > continues to grow. > > Joint 2 is your Z axis. (Joint numbers start from zero.) So, either your servo tuning is not good, or something you did when setting up the XYZX configuration in the hal files has broken the proper connection of signals related to the Z axis. You should NOT need to set up 4 axes in [TRAJ], as far as LinuxCNC is concerned, this is a 3-axis machine. Only the motor side needs to know about the 4th motor. It is NOT a separate axis, it is only an extra motor added to an existing axis.
So, you DO need 4 PIDs if you have encoders feeding back position, but you don't need a 4th AXIS. If you don't have encoders, then you may not need any special details to move the 4th motor. Or, you could use another step generator for the 4th motor, and gate that with something related to homing the gantry so that motor is in proper alignment to the other side of the gantry. Jon ------------------------------------------------------------------------------ Dive into the World of Parallel Programming. The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
