Tom Easterday wrote: > Thanks for the info Jon. We are seeing a small (about 0.001) position error > just on initial acceleration and deceleration that we cannot account for. It > may be due to the encoder. Since this is mainly a plasma machine we will > probably live with it. If we need to do better we'll look at replacing the > encoders. We now know the string attached to our cheap encoder If you can send me a picture form Halscope, I can compare it to what I get. Are you using FF2? This can be quite helpful in fixing errors on acceleration. You have to use it in VERY small amounts, though, like .005 or even less. It is easy to add too MUCH FF2 and cause jerks in the response. Also, there is a manufacturing issue in these, where the encoder ring may fit loosely on the splined hub that mounts to the shaft. On some units you need to put a little dab of RTV, super glue or whatever on the splined hub to lock the ring to it. You can poke the ring with an X-acto knife to see if there is any play between it and the hub when the whole thing is assembled.
Jon ------------------------------------------------------------------------------ Systems Optimization Self Assessment Improve efficiency and utilization of IT resources. Drive out cost and improve service delivery. Take 5 minutes to use this Systems Optimization Self Assessment. http://www.accelacomm.com/jaw/sdnl/114/51450054/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
