On 08/16/2011 11:15 PM, Scott Hasse wrote: > All- > > I'm about a month into retrofitting an older Anilam 1100M 3-axis mill to > EMC2 using a Mesa 5i23 PCI board with a 7i33TA for servo interfacing and > 7i37TA for general I/O. I'm documenting the build here: > > http://code.google.com/p/sector67-sandbox/wiki/ProjectSheetCake > > with my build notes here: > > http://code.google.com/p/sector67-sandbox/wiki/SheetCakeBuildLog > > although my documentation is a work in progress, you can get a feel for > where I am at with this project. It's volunteer work for a hackerspace and > eventually EMC2 is going to enable us to do all sorts of interesting stuff > with this hardware. > > I have been extremely impressed with the overall maturity and capability of > the EMC2 ecosystem. The live CD was an absolute time saver and wonderful > resource. The sample configurations got me basically going out of the box, > pncconf has been unbelievably helpful as I've advanced in what is hooked up, > and halmeter and halscope are pure genious. Great job to all involved, and > I hope to do my small part by documenting another mill conversion in > (hopefully) very accessible detail. > > To the point, though, I am having one not-so-minor problem. When I enable > the servos, they are not completely stable, and I'll get following error > almost immediately after enabling them. They don't run away, but the > encoders show them moving ever so slightly, and physically the motors > actually are moving. > > The Anilam system I'm converting is a servo drive with velocity feedback > directly to the servo amps and rotary encoder output that I've wired to the > 7i33TA board. The servo amps take +/-10V for direction and velocity. I can > move the axis using the pncconf tuning page, and have tried to stabilize > them using the DAC compenstation, but there is not a fixed amount of DAC > compensation that seems to work. The Anilam controls still work perfectly > fine and the servos are stable when that control is running. > > I suspect a problem like ground differential, but the cable to the servo amp > has ground, signal and shielding, so I was thinking I should be OK. Despite > the schematic on the wiki above, I am not powering the 7i33TA or 7i37TA > on-board, but instead am using cable power (but I believe that is the only > inaccuracy in the schematic). The 50 pin ribbon cables are ~3 feet. > > Would it be better to power the boards from the 5V supply already in the > chassis? Is this a problem that can be solved with PID tuning? Has anyone > seen anything like this? I've searched the email list and have not been > able to find anyone with the same problem. > > Thanks very much in advance, > > Scott > Scott,
I like the setup of your documentation. Does it allow pictures? As we all know, unless you have pictures, it didn't happen... ;-) It's nice to see the beginning through the end of the rebuild through photos, and Sam likes to take videos of his tiny machines. We all here enjoy cheering on machine builds. And the folks here, on the web site forum, and on the IRC are about the most helpful group of folks you'll ever meet. I'm very thankful to the gents both here and on the IRC that walked me through setting up my oddball machine, and helped me over the speed bumps. Mark ------------------------------------------------------------------------------ Get a FREE DOWNLOAD! and learn more about uberSVN rich system, user administration capabilities and model configuration. Take the hassle out of deploying and managing Subversion and the tools developers use with it. http://p.sf.net/sfu/wandisco-d2d-2 _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
