On Friday 11 September 2009, Ian R Upton wrote: >Gentlefolk, > >Thanks for all the comments and suggestions. > >Back looking at the basics. How do I know the motor is 50 steps/rev??? > >The motor is an Epson EM-257 which I have not been able to find much >about on the Internet. > >I held the shaft of the motor and rotated it carefully. 50 "steps" >(harder movements) per rev. > >Originally the thing seemed to go beserk when run at 200 steps/rev. But >this may have been effected by my early settings, excess current, >velocity, etc. > >I have just set the steps/rev to 200 and am now starting to fiddle >current, velocity, etc. Looks encouraging. > >So how do I determine the number of steps per rev accurately?? > >Ian
You have the right steps when the motion is otherwise accurate. For me, using 1.8 degree/step motors and a xylotex driver set at 8 microsteps, that is 1600 steps/rotation. With 20 tpi acme screws on the x/y, then its 32000steps/inch. You noted that you got a higher speed from 1/2 step than from full step. I don't know about your drivers, but the higher the microsteps, the less torsional vibration there will be per microstep taken, and the higher the speed will be achieved. The speed potential when running without dampers can be quite adversely impacted by this when the step rate and the vibration of the step are in resonance, even when running at 8 microsteps. I doubled the speed of my machine with the dampers I made, from a steel spool with one end flange removable/adjustable, some 1/8" sheet rubber similar to inner tube rubber, and a stack of the largest fender washers I could get at Tractor Supply. You can see them at <http://gene.homelinux.net:85/gene/emc> on the back ends of the motors. The shaft diameter just fits the holes in the fender washers, and the rubber washers holes were cut well undersized so that the rubber, by being stretched over the shaft has both a good grip on the shaft, and its fatter near the center & functions as a slip clutch to the steel washers. Magic marker the washers so you can see if they slip and adjust the tension on the stack so they do slip when its running. -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. <https://www.nrahq.org/nrabonus/accept-membership.asp> echo "ICK, NOTHING WORKED!!! You may have to diddle the includes.";; -- Larry Wall in Configure from the perl distribution ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
