<cogo...@...> writes: > > where I work we have a Shizuoka with an old Bandit control. ...
> I would like to convert this to an EMC2 servo system with quadrature encoders for feedback to EMC2, and for > the proof of concept, I'd like to have EMC2 do pulse-width-modulation of 3 parallel port pins, which I > would convert to +- 10V with a quad op amp and filter circuit (already have those parts). Since I'd be > spending someone else's money, I'd like to avoid buying a Pluto servo board, or a MESA 5i20 until I can prove > it can cut parts. I'm also planning on doing an "open quadrature encoder" project, to save some bucks up > front, and hopefully come up with a cheap and fairly reliable replacement for expensive encoders. > cogoman, I just converted a Kasuga knee mill that had a Bandit III controller on it. I am very happy with the conversion. Going from the Bandit to Emc2 was like trading in my Volkswagen for a Ferrari. The Emc2 controller is way faster, smoother, and more accurate. The old Bandit used to impart dwell marks on all of my parts no matter how I tuned the backlash settings. Now all my curved surfaces are smooth and I have no backlash marks at all. I am using my old brush servos which I retrofitted with inexpensive Renco RCML15-500/0 encoders (ebay) that were reasonably simple to install. I upgraded my amplifiers to Advanced Motion AC powered units (no transformer) and I used the Mesa 5i20 and 7i33. I also have flood/mist coolant, and a vfd powered spindle motor with an encoder on the spindle so I can do tapping. I don't know what your time frame is, but I am concerned that if you try to save some bucks by making your own proof of concept control and feedback circuits, you may only prove that it takes too much time to be practical. It took me about 6 weeks from the moment I ripped out the old Bandit until I was back making parts again. I had no hardware, computer, or software problems. The Mesa cards performed flawlessly. I had some issues with noise in my 15 ft. long ribbon cables which caused false tripping on my limit switch inputs, but I solved the problem by using a "debounce" hal filter function. Learning to configure the ini and hal files was the steepest learning curve, but there are a lot of smart, and friendly people here on this forum that helped me with my questions - in fact I often got answers to my questions within hours. Near the completion of my conversion it took me a few weeks to familiarize myself and get comfortable with the Emc2 gcode commands and tool length offset system. Now I am making parts faster than I thought possible. I highly recommend Emc2 - assuming that your Shiz was well cared for, I think you will be amazed at what it will be capable of under the control of Emc2. You may even want to build some sort of chip/coolant shield enclosure for it because I bet you will use it a lot more. ------------------------------------------------------------------------------ Open Source Business Conference (OSBC), March 24-25, 2009, San Francisco, CA -OSBC tackles the biggest issue in open source: Open Sourcing the Enterprise -Strategies to boost innovation and cut costs with open source participation -Receive a $600 discount off the registration fee with the source code: SFAD http://p.sf.net/sfu/XcvMzF8H _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
