While I can't comment on the wireless network other than it should work. I do have some comments on steppers and encoders. Unless you have some real high rent stepper drives capable of running your steppers at rediculess micro step counts encoder feedback is poimtless. First thing a proper stepper setup should NOT lose steps! Second if you add all the variables, tolerances, assembly, and missalignments in the machine you still probably can't justify using encoder feedback. Unless your machine is extremely accurate and near perfectly aligned, you would need drives and motors capable of very high microstep counts. Then your steppers could be run with encoder feedback and would act more like servos than steppers. IMO it would be much more cost effective and practical to just switch to actual servo drives. Less burden on the computer (EMC) and easier to implement. Glass scales are also expensive at high resolutions. To use Glass scales for position feedback requires a very tight positioning system with zero or near zero backlash. I'm sure that encoder feedback is possible to setup, I just don't see the need or benefit of it. Last words, a properly setup stepper system should NOT LOSE STEPS! And minor amounts of backlash can probably be ignored. I have .002" ~ .003" backlash. It's not really backlash but more of a windup due to motor coupling and the extra load of spring loaded anti backlash nuts. It doesn't present a problem as the machine repeats within .001 or better so the windup issue get's ignored and I have no problems with it.
Just my 25 cents, (inflation) Dale RogerN wrote: > Would my EMC2 system work with USB wireless networking? I'm thinking of > this because I could connect the USB wireless adapter to a USB extension > and position it for better reception. I'm just not sure if it would > work on my Ubuntu Linux EMC2 system. Another option would be a PCI card > and an external antenna with cable. > > Also, after getting to play with hal configurations a bit, It seems like > it wouldn't be too difficult to get steppers working with encoder > feedback. If you would set up a pid loop => frequency generator and > configure velocity feed forward to run the steppers at the commanded > velocity, then pid gains could be set to take care of position > deviations. This would be useful in detection and correction of lost > steps for one. It would also give you the ability to connect encoders > directly to lead screws or use linear encoders for actual position > feedback. It seems like this would be a little more to set up than just > plain open loop steppers but shouldn't be much more difficult than > setting up a servo system. I don't think I've ever heard of a stepper > based system that is capable of positioning from linear scales. That > should take care of lost steps, lead screw errors, minor amounts of > backlash, etc. > > Just a thought... > > Roger Neal > > > > > ------------------------------------------------------------------------- > This SF.net email is sponsored by: Splunk Inc. > Still grepping through log files to find problems? Stop. > Now Search log events and configuration files using AJAX and a browser. > Download your FREE copy of Splunk now >> http://get.splunk.com/ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
