< copy from .ini> MAX_VELOCITY = 1.5 MAX_ACCELERATION = 1.5 STEPGEN_MAXVEL = 1.7 STEPGEN_MAXACCEL = 1.7 BACKLASH = 0.0000 <end copy> OK so max velo is 90 ipm seems pretty hot for steppers but I'm not a stepper person. On the other hand the accel at 1.5 seems pretty soft. Stepper people can advise better but I should think that 4-6 would be closer. I don't have it straight in my mind which way the max accel and stepgen max accel should be... i.e which one should be larger. Just poking in hopes it may do some good. :-) Lets hope the 'experts' solve this one. ;-) How do things look if you put a long travel dial indicator ( e.g. 1" ) on an axis and do the back and forth stuff?
Dave On Jun 5, 2007, at 6:23 PM, Jon Elson wrote: > Jack Ensor wrote: >> Jon Elson wrote: >>> If you make >>> several 1" moves in the same direction with incremental jog, >>> what is the error? >>> >> >> Zero, ignoring backlash when giving it individual G1 or G0 commands. > The rest of your data is hard to interpret. I think the most > important piece is this one, that the error only happens when > the direction changes! That has to mean something. With > step/direction drives, the most common error is from the > direction signal changing too soon, while the steps are still > being generated by the drive. That can't be the case here, as I > understand it. > > I would suggest you slow down the acceleration markedly, and see > if the problem changes. I also note that the X problem doesn't > seem that bad, and could be partially attributed to the > machine's actual position landing somewhere within the backlash > bound. The Y axis is so much worse that I have to start looking > at hardware. Why should the Y axis be showing so much more > change in position than X? The software driving the axes are > the same. Maybe you have a bad transistor, bad motor, loose > pulley or coupling, etc. > > But, what I was getting at above was if the error only shows up > on direction reversals, then maybe the "bump" that happens when > the backlash is taken up causes the motor to jump a few > multiples of 4 full steps. Slower acceleration would allow the > motor to still be moving slower when it bumps into the other > side of the leadscrew/nut. > > Jon > > ---------------------------------------------------------------------- > --- > This SF.net email is sponsored by DB2 Express > Download DB2 Express C - the FREE version of DB2 express and take > control of your XML. No limits. Just data. Click to get it now. > http://sourceforge.net/powerbar/db2/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------- This SF.net email is sponsored by DB2 Express Download DB2 Express C - the FREE version of DB2 express and take control of your XML. No limits. Just data. Click to get it now. http://sourceforge.net/powerbar/db2/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
