R Rogers wrote: > >Jon Elson <[EMAIL PROTECTED]> wrote: > > > >But, Mach2 doesn't actually USE the encoder information, except to >display it on the screen. If a motor stalls and it is a whole inch out of >position, it pays no attention, just displays where the machine actually >is, while blindly continuing to ruin the workpiece. What's the purpose >of encoder feedback, if not to keep track of machine position? > >Jon > >Ok. I'm confused here. I understood that Geckos after a 128 pulse/count >dicrepancy between encoder and drive will fault. At 800 counts per revolution >and 2.5 :1 reduction on the drive would only allow about .020" positioning >error before faulting. If I understand this correctly. Incidently, I've used a >Mach2/Gecko setup on a Bridgeport and have not lost a step/ruined a part due >to lost position nor ever lost position in a year and a half under normal >operation. To term it a "Hobby" or not a "Real" control software is a bit >unfair. It reliably does what it is supposed to do. Without the "Real" >software price and they do nothing more than hold position like Mach2. A >software that monitiors axis position via encoder feedback is only required >when the axis actuator is inadequate for the task at hand i.e. insufficient >torque etc. Who wants that anyway? > Well, the difference is that with Gecko drives you don't know WHERE in that +/- .020" region the machine actually is. (Normally it is very close to the commanded position, but you don't know for sure.) As the velocity increases, the following error increases. For some applications, a .020" error is totally unacceptable. For others, it would be no problem.
Obviously your bridgeport setup satisfies your needs, and that is great. Mach2 and Gecko (or Xylotex, Rutex, etc.) drives are making a lot of parts for a lot of people. EMC costs LESS than Mach2, and does offer encoder feedback to the PC. One thing this allows is a sliding scale of acceptable following error. You can permit a larger following error at rapid traverse speeds, but a very small following error limit for low-speed cutting moves. Also, you can switch back and forth between CNC and manual movement (on machines with handwheels) with the same coordinate system. I don't know if it works that way in Mach2. Jon Addresses: FAQ: http://www.ktmarketing.com/faq.html FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/ Post Messages: [EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] Unsubscribe: [EMAIL PROTECTED] List owner: [EMAIL PROTECTED], [EMAIL PROTECTED], [EMAIL PROTECTED] Moderator: [EMAIL PROTECTED] [EMAIL PROTECTED] [EMAIL PROTECTED] [Moderators] URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO OFF Topic POSTS: General Machining If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if you have trouble. http://www.metalworking.com/news_servers.html http://groups.yahoo.com/group/jobshophomeshop I consider this to be a sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list. NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........ bill List Mom List Owner Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
