I tried to explore different possibilities and I am turning to use LinuxCNC to close a PID loop and maybe use MESA cards, but.. Where should I seek for motors, compatible with 7i39? If not 7i39, where to seek for PWM / dir or analog amplifiers, servo motors? Would you give some good suggestions?
Marius On 2013.04.02 19:18, Dave wrote: > If you can keep the required step rate within reason, the LPT port works > fine for industrial stuff. If you need to go fast, there are cards > that can increase your step rate obviously and for low cost. > If you already have analog only drives then the solution is to go with > analog interfaced servos obviously. But the number of machines being > controlled via step and direction is huge, especially for low end > machines which > is what I think you are talking about. > I do not consider Mesa cards to be expensive, but perhaps your machines > are very inexpensive.. so then it becomes a "relative cost issue". > Also, the more you buy the cheaper they get. > If you don't need speed and high power, most of what you need can > probably be done with stepper motors. Less than 200 watts is stepper > motor territory. > > Using an LPT port with a stepper driver and motor is about as > inexpensive as you can get for motion control. If you need more power, > you can move up to a step and dir interfaced Servo drive. > > Dave > > > > On 4/2/2013 4:23 AM, andy pugh wrote: >> On 2 April 2013 09:19, propcoder<[email protected]> wrote: >> >> >>> The question is: which way to go? >>> >> I guess there are two ways to do this, either choose the optimum for >> each application, or try to find one technology which fits all >> applications. >> >> The latter approach is likely to be a lot more expensive, but does >> have the advantage that upgrades will simply involve bigger motors >> and/or bigger drives and no changes to the control system. >> >> >>> 1. Take AC servo motors and drives like Yaskawa, Panasonic, Delta >>> electronics, add gearboxes, tune PID, use position control mode using >>> LPT and step/dir. >>> 2. The same as 1, but with mesa card and velocity control mode, position >>> loop in LinuxCNC. I think this way is logical only where trajectory >>> following needed. >>> >> I don't think I would consider using the parport in an industrial >> setting. However I might be tempted to use step-dir servo drives with >> internal position control for the more undemanding applications. >> If all that is needed is for something to go to a position, then a >> Limit3 and stepgen is easily controlled direct from HAL. >> >> >>> As for the 5th, I think it is possible to use a bridge, make PWM >>> frequency booster or serial-in to PWM-out controller with current >>> limiter and encoder counter with serial shift-out interface. >>> >> It is possible to control a 3-phase inverter bridge directly from a >> Mesa card, the three-phase PWM generator and the HAL bldc component do >> all that is required. >> However, I doubt it makes sense to install home-brew drives in an >> industrial setting, especially if the plan is to install, get paid, >> and walk away. >> >> > > ------------------------------------------------------------------------------ > Own the Future-Intel(R) Level Up Game Demo Contest 2013 > Rise to greatness in Intel's independent game demo contest. Compete > for recognition, cash, and the chance to get your game on Steam. > $5K grand prize plus 10 genre and skill prizes. Submit your demo > by 6/6/13. http://altfarm.mediaplex.com/ad/ck/12124-176961-30367-2 ------------------------------------------------------------------------------ Minimize network downtime and maximize team effectiveness. Reduce network management and security costs.Learn how to hire the most talented Cisco Certified professionals. Visit the Employer Resources Portal http://www.cisco.com/web/learning/employer_resources/index.html _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
